Articles de revues : « Panicle development »

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Dai, Dongqing, Huali Zhang, Lei He, Junyu Chen, Chengxing Du, Minmin Liang, Meng Zhang, Huimei Wang et Liangyong Ma. « Panicle Apical Abortion 7 Regulates Panicle Development in Rice (Oryza sativa L.) ». International Journal of Molecular Sciences 23, n^o 16 (22 août 2022) : 9487. http://dx.doi.org/10.3390/ijms23169487.

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The number of grains per panicle significantly contributes to rice yield, but the regulatory mechanism remains largely unknown. Here, we reported a loss-of-function mutant, panicle apical abortion 7 (paa7), which exhibited panicle abortion and degeneration of spikelets on the apical panicles during the late stage of young panicle development in rice. High accumulations of H2O2 in paa7 caused programmed cell death (PCD) accompanied by nuclear DNA fragmentation in the apical spikelets. Map-based cloning revealed that the 3 bp “AGC” insertion and 4 bp “TCTC” deletion mutation of paa7 were located in the 3′-UTR regions of LOC_Os07g47330, which was confirmed through complementary assays and overexpressed lines. Interestingly, LOC_Os07g47330 is known as FRIZZY PANICLE (FZP). Thus, PAA7 could be a novel allele of FZP. Moreover, the severe damage for panicle phenotype in paa7/lax2 double mutant indicated that PAA7 could crosstalk with Lax Panicle 2 (LAX2). These findings suggest that PAA7 regulates the development of apical spikelets and interacts with LAX2 to regulate panicle development in rice.

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Chamberlin, J. R., et J. N. All. « Influence of Panicle Maturity on Infestation of Grain Sorghum by Corn Earworm and Sorghum Webworm (Lepidoptera : Noctuidae) in Georgia ». Journal of Entomological Science 26, n^o 4 (1 octobre 1991) : 419–24. http://dx.doi.org/10.18474/0749-8004-26.4.419.

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The influence of panicle maturity on oviposition by the corn earworm, Helicoverpa zea (Boddie), and sorghum webworm, Celama sorghiella (Riley), was investigated on grain sorghum in Georgia during 1986 and 1987. Stage of panicle development, density of corn earworm and sorghum webworm, and egg parasitism by Trichogramma spp. were recorded at 2–3 day intervals in three field tests. Sorghum webworm and corn earworm began oviposition as panicles emerged from the boot. Oviposition peaked 4–8 days later, near the time panicles began anthesis, but then declined quite rapidly. Oviposition by sorghum webworm ceased approximately 10–12 days after panicle emergence began. Corn earworm oviposition continued at low levels until sampling was terminated 14 - 17 days after panicles began emgergence. Rainfall appeared to mediate effects of panicle maturity on oviposition. Corresponding peaks in larval density were not observed for corn earworm or sorghum webworm, possibly because of heavy parasitism by Trichogramma spp. A paired comparison procedure was used to determine preference of small, medium, and large corn earworm larvae for panicles of different maturity. Early instars preferred newly flowered panicles and concentrated feeding on pollen filled anthers. Late instars preferred panicles in the soft-hard dough stages, while intermediate instars exhibited no significant preference. These data suggest that corn earworm oviposition is concentrated at anthesis because pollen enhances larval development and survival.

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Menzel, CM, et DR Simpson. « Flowering and fruit set in lychee (Litchi chinensis Sonn.) in subtropical Queensland ». Australian Journal of Experimental Agriculture 32, n^o 1 (1992) : 105. http://dx.doi.org/10.1071/ea9920105.

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The pattern of panicle and flower development of lychee (Litchi chinensis Sonn.) trees was studied in subtropical Queensland (lat. 27�S.). The cultivars studied were Tai So at 3 sites, Bengal at 4 sites, Kwai May Pink at 2 sites, Salathiel at 3 sites, and Wai Chee at 2 sites. Tai So was the earliest cultivar, with panicle emergence in late May and flower anthesis in mid September. The other cultivars were 5-7 weeks later. Tai So had a longer period of flower anthesis than the other cultivars (4 weeks v. 1-3 weeks). Cultivars Tai So and Bengal generally had longer panicles than cvv. Kwai May Pink, Salathiel and Wai Chee (17-32 v. 10-14 cm), and more flowers per panicle (1800-3400 v. 400-900). Similarly, the number of fruit per panicle ranged from 7-33/panicle 2-3 weeks after the end of flowering, to 4-22/panicle at harvest. The proportion of female flowers setting fruit ranged from 2.1 to 19.5%. Similar estimates for fruit carried to harvest ranged from 0.8 to 6.8%. Variations in the times of panicle emergence, panicle development, and anthesis among the cultivars in relation to seasonal progressions in temperature affected the number of fruit set. The number of fruit set per panicle increased as the number of female flowers per panicle increased. Higher numbers of female flowers were associated with maximum temperatures during flower development of 18�C, with lower numbers at 23�C. Higher maximum temperatures during anthesis (30�C v. 24�C) increased the proportion of female flowers setting fruit.

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ABBASI, M. F., A. U. DIN et F. M. ABBASI. « DEVELOPMENT OF NEW RICE STRAIN WITH IMPROVED SINK SIZE AND SOURCE CAPACITY USING A MULTI-PARENT ADVANCED GENERATION INTERCROSS (MAGIC) APPROACH ». SABRAO Journal of Breeding and Genetics 54, n^o 5 (31 décembre 2022) : 963–75. http://dx.doi.org/10.54910/sabrao2022.54.5.1.

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A new rice strain that grows six feet tall with four times higher potential yield than the conventionally bred variety, JP5, was developed using the MAGIC approach. This new rice type underwent analysis on sink size and source capacity traits, including superior and inferior spikelets, vascular bundles of panicle neck and stem internode, tillering pattern, grain filling pattern, yield, and other morphological attributes. Results indicated that the new strain had more vascular bundles of the stem (42) and panicle neck (35), primary rachis branches of panicle (16.1), superior spikelets, and greater grain weight than the conventionally bred variety, JP5. The panicle measured 45 cm long, with fertile grains of 500 per panicle and a stem diameter of 1.2 cm. During the grain filling duration, the spikelets of this strain and superior spikelets of JP5 gained maximum weight earlier than the inferior spikelets of JP5. Six feet tall plants of this new strain with long and heavy panicles had greater stem wall thickness. There occurred a positive and significant correlation (0.97) between yield and small vascular bundles of the panicle neck, lumen diameter (0.98), leaf length (0.99), leaf width (0.99), flag leaf length (0.99*), flag leaf width (0.97<), panicle length (0.97), fertile grains per panicle (0.98), and plant height (0.97*). The study noted that improving sink size, source capacity, and transportation of assimilation contributed positively toward yield. This novel strategy for grain yield enhancement in rice proved beneficial for other cereals to get significant breakthroughs in their production for ensuring food security.

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Hastini, Tri, Irma Noviana, Yati Haryati, Bebet Nurbaeti, M. Iskandar Ishaq, Fyannita Perdhana, Ratna Sari et Iyan Septiana. « Panicle branching behaviour of rice Inpari IR Nutri Zinc ». E3S Web of Conferences 316 (2021) : 03002. http://dx.doi.org/10.1051/e3sconf/202131603002.

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As a staple food, rice can be used as a bio fortification. For this necessity, Indonesian Agency for Agriculture Research and Development (IAARD) developed rice variety which was rich of Zn content to overcome child stunting. To understand the panicle branching behavior of Inpari IR Nutri Zinc, we collected panicle branching data from different sites and agronomical practices. Data were collected from three locations in West Java, i.e Cianjur, Majalengka, and Ciamis during May until October 2020. Among sites showed a significant differences of panicle branching. The best performance of Inpari IR Nutri Zinc panicle branching was showed at Majalengka rather than Ciamis and Cianjur. It was predicted because of temperature differences, as Cianjur’s was higher than those Majalengka’s and Ciamis’. Based on planting space, L5 was better than that L2 in number of grains per panicle, number of primary branches, number of secondary branches, total length of primary branches, and number of filled-grain per panicle characters. Meanwhile, L2 in Majalengka and Ciamis showed higher value in three panicle branching characters. Further, the L2 in Majalengka showed higher value and significantly difference than that in Ciamis in seven panicles branching characters bio pesticide application also affected some panicle branching characters significantly.

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Gaballah, Mahmoud, Hassan Hamad, Atif Bamagoos, Hesham Alharby, Sharif Ahmed, Ismail A. Ismail, Md Sohidul Islam et Ayman EL Sabagh. « Flowering Synchronization in Hybrid Rice Parental Lines at Different Sowing Dates ». Sustainability 13, n^o 6 (15 mars 2021) : 3229. http://dx.doi.org/10.3390/su13063229.

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Hybrid seed set on the female line depends primarily on its flowering synchronization with the restorer line (R), therefore, the sowing of male and female lines must be planned properly to achieve this. Field experiments on different sowing dates (May 1st, May 15th, and May 30th) of R lines (Giza 178R, Giza 179R, and Giza 181R) and cytoplasmic male sterile (CMS) lines (IR69625A, IR70368A, IR58025A, K17A, and G46A) were carried out at the farm of Sakha Agricultural Research Station, Kafr El-Sheikh, Egypt during 2019 and 2020 to study the effect of sowing dates on flowering synchronization in hybrid rice. The results indicated that the synchronization of flowering between CMS lines and R lines has highly significant effects on the days to 50% heading, number of leaves, effective accumulated temperature (EAT), plant height, panicle exertion percentage, panicle length, number of fertile panicles, panicle weight, seed set percentage, harvest index and seed yield of hybrid rice. The highest seed yield (1.72 and 1.41 t ha−1, respectively in 2019 and 2020) was recorded from the sowing date May 1st and the hybrid combination of Giza 178R × IR58025A (2.06 and 2.12 t ha−1 in 2019 and 2020, respectively). The grain yield had a significant and highly significant positive correlation with the plant height (cm), panicle exertion percentage, panicle length, number of panicles plant−1, panicle weight, seed set percentage, and harvest index. In Egypt, May 1st is the best time for the synchronization of hybrid rice lines and a combination of Giza 178R × IR58025A may be recommended for better performance.

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BROWNE, R. A., E. M. WHITE et J. I. BURKE. « Responses of developmental yield formation processes in oats to variety, nitrogen, seed rate and plant growth regulator and their relationship to quality ». Journal of Agricultural Science 144, n^o 6 (2 novembre 2006) : 533–45. http://dx.doi.org/10.1017/s0021859606006538.

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Outcomes of developmental yield formation processes in oats, namely number of panicles/m2, number of grains/panicle, mean grain weight and incidences of aborted and tertiary grains, were measured in a series of experiments in Northern Ireland and the Republic of Ireland in 1997/98 and 1998/99. Seed rate (200 and 300 seeds/m2), nitrogen (0–200 kg/ha) and plant growth regulator (chlormequat chloride) treatments were applied to the spring oat varieties Aberglen and Barra in one spring- and two autumn-sown experiments, and to the winter varieties Gerald and Image in one autumn-sown experiment. Large variation in number of panicles/m2 and grains/panicle was observed between the experiments and varieties and in response to seed rate, with number of grains/panicle generally being inversely related to number of panicles/m2. At the higher rates of nitrogen rate both number of panicles/m2 and grains per panicle increased. Mean grain weights were relatively constant and were largely determined by variety. Chlormequat chloride had relatively little effect on the yield components, the most consistent being small reductions in mean grain weight.Tertiary grains occurred rarely in the varieties and agronomic treatments used in the programme but were more frequent at higher rates of nitrogen in most of the experiments. Numbers of aborted grains were usually higher where grain numbers were higher although the effects of variety, seed rate and nitrogen on aborted grains were not consistent. Structure of the grain population, i.e. the relative proportions of primary and secondary grain, was stable despite the large differences in number of panicles/m2, spikelet numbers and mean grain weight.The greater yield and growth enhancing effects of nitrogen compared with seed rate and plant growth regulator were apparent in responses by developmental processes active later in the life cycle, namely production of tertiary grains and grain filling.Wide variation in number of panicles/m2 (c. 200–450) and number of grains/panicle (c. 55–145) produced in the crops grown under a very full expression of agro-ecological conditions in this programme was accompanied by small variation in mean grain weight (c. 38–47 mg/primary grain and c. 22–29 mg/secondary grain) and in numbers of tertiary (<2/panicle) and aborted grains (<10/panicle). Plasticity of development throughout the life cycle, manifested both as the established yield components and in numbers of tertiary and aborted grains, was largely effective in ensuring stability of mean grain weight and quality in oats.

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Wang, Yaliang, Yikai Zhang, Qiang Zhang, Yongtao Cui, Jing Xiang, Huizhe Chen, Guohui Hu et al. « Comparative transcriptome analysis of panicle development under heat stress in two rice (Oryza sativa L.) cultivars differing in heat tolerance ». PeerJ 7 (29 août 2019) : e7595. http://dx.doi.org/10.7717/peerj.7595.

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Heat stress inhibits rice panicle development and reduces the spikelet number per panicle. This study investigated the mechanism involved in heat-induced damage to panicle development and spikelet formation in rice cultivars that differ in heat tolerance. Transcriptome data from developing panicles grown at 40 °C or 32 °C were compared for two rice cultivars: heat-tolerant Huanghuazhan and heat-susceptible IR36. Of the differentially expressed genes (DEGs), 4,070 heat stress-responsive genes were identified, including 1,688 heat-resistant-cultivar-related genes (RHR), 707 heat-susceptible-cultivar-related genes (SHR), and 1,675 common heat stress-responsive genes (CHR). A Gene Ontology (GO) analysis showed that the DEGs in the RHR category were significantly enriched in 54 gene ontology terms, some of which improved heat tolerance, including those in the WRKY, HD-ZIP, ERF, and MADS transcription factor families. A Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed that the DEGs in the RHR and SHR categories were enriched in 15 and 11 significant metabolic pathways, respectively. Improved signal transduction capabilities of endogenous hormones under high temperature seemed to promote heat tolerance, while impaired starch and sucrose metabolism under high temperature might have inhibited young panicle development. Our transcriptome analysis provides insights into the different molecular mechanisms of heat stress tolerance in developing rice.

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Xi, Te, Huaiqu Feng, Yongwei Wang, Dunhong Yang, Dongfang Li, Fuqiang Yao et Jun Wang. « Optimizing the Working Parameters of Pneumatic Pollinators Based on the Kinematic Properties of Rice Panicles ». Journal of the ASABE 66, n^o 1 (2023) : 65–74. http://dx.doi.org/10.13031/ja.15308.

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Highlights An experimental platform for the kinematic characteristics of panicles was constructed. A regression model for the kinematic characteristics of panicles and working parameters was established. The multi-objective optimization based on the kinematic characteristics of rice panicles was carried out. The optimized combination of working parameters was verified by field pollination experiments. Abstract. Pollen shedding and dispersal processes are inextricably linked to the movement state of hybrid rice panicles. The purpose of this work was to study the effect of the working parameters of the pneumatic pollinator on the kinematic characteristics of hybrid rice panicles during flowering and to further optimize the working parameters of the pollinator. An experimental platform was built to characterize the movement of the panicle. Orthogonal experiments were conducted with airflow velocity, action position, and walking speed as experimental factors and kinematic parameters such as displacement, velocity, and acceleration of the rice panicle as experimental indicators. A quadratic regression model between the working parameters and the motion characteristics of the rice panicle was constructed and analyzed by analysis of variance (ANOVA). Matrix analysis was used for multi-objective optimization of the working parameter combinations. Field pollination trials were conducted for the optimized combination of parameters. The results showed that the coefficients of determination of the regression models were all above 0.85, which indicated good accuracy. The motion characteristics of the panicle, including the displacement maximum, velocity maximum, and acceleration maximum, can be maintained at a high level when the airflow velocity is 24 m/s, the action position is 120 mm from the top of the panicle, and the walking speed is 0.4 m/s. The field experiments showed that the optimization results could obtain the desired pollen density, distribution, and uniformity. This study can serve as a reference for the development of pneumatic hybrid rice pollination theory and the optimal design of the pollinator structure. Keywords: Hybrid rice seed production, Kinematic characteristics, Mechanized pollination, Multi-objective optimization.

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He, Dong, Rui Liang, Tuan Long, Ying Yang et Changyin Wu. « Rice RBH1 Encoding A Pectate Lyase is Critical for Apical Panicle Development ». Plants 10, n^o 2 (30 janvier 2021) : 271. http://dx.doi.org/10.3390/plants10020271.

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Panicle morphology is one of the main determinants of the rice yield. Panicle abortion, a typical panicle morphological defect results in yield reduction due to defective spikelet development. To further elucidate the molecular mechanism of panicle abortion in rice, a rice panicle bald head 1 (rbh1) mutant with transfer DNA (T-DNA) insertion showing severely aborted apical spikelets during panicle development was identified and characterized. The rbh1-1 mutant showed obviously altered cell morphology and structure in the degenerated spikelet. Molecular genetic studies revealed that RBH1 encodes a pectate lyase protein. Pectate lyase-specific activity of Rice panicle Bald Head 1 (RBH1) protein assay using polygalacturonic acid (PGA) as substrates illustrated that the enzyme retained a significant capacity to degrade PGA. In addition, immunohistochemical analysis showed that the degradation of pectin is inhibited in the rbh1-1 mutant. Further analysis revealed that a significant increase in reactive oxygen species (ROS) level was found in degenerated rbh1-1 spikelets. Taken together, our findings suggest that RBH1 is required for the formation of panicle and for preventing panicle abortion.

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Chanon, Ann M., Pablo S. Jourdan et Joseph C. Scheerens. « (233) Comparison of Inflorescence Morphology, Anthesis and Floral Sex Expression in Bottlebrush and Red Buckeye ». HortScience 41, n^o 4 (juillet 2006) : 1020B—1020. http://dx.doi.org/10.21273/hortsci.41.4.1020b.

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As a prelude to interspecific hybridization, we compared the floral biology of bottlebrush buckeye (Aesculus parviflora) and red buckeye (A. pavia) by examining inflorescence morphology, pattern of floral anthesis, sex expression, and the effects of panicle decapitation on complete flower development. Inflorescences of both species (n = 1606) were randomly selected and analyzed for length, total number of flowers and complete flower number and location. The pattern of anthesis was observed in four genotypes using 10–30 inflorescences per plant. For each flower, its date of anthesis, position on both the rachis and cincinnus, and sex were recorded. For studies of panicle decapitation, sets of panicles were selected and one member was severed in half early in development in an attempt to increase the number of complete flowers. More than one-fourth of all panicles observed were completely staminate. For both species, the ratio of complete flowers to male flowers (C:M) within mixed panicles was about 5%. Complete flowers were observed in the basal portion of A. pavia inflorescences and in the apical portion of A. parviflora inflorescences. Anthesis progressed from base to tip over a period of 6–11 days. Complete flowers are present in A. pavia from the beginning of anthesis but do not appear in A. parviflora until the fifth day of anthesis. Staminate flowers are present throughout anthesis in both species. Severing panicles in half increased the potential for differentiating complete flowers. In conclusion, the frequency of complete flowers in both species was quite low, but could be increased by panicle decapitation to increase opportunities for controlled hybridization.

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Suaib, Suaib, Woerjono Mangoendidjojo, PDN Mirzawan et Ari Indrianto. « PROPORSI MIKROSPORA UNINUKLEAT PADA EMPAT KLON TEBU (Saccharum spp.) ». Berkala Penelitian Hayati 12, n^o 2 (30 juin 2007) : 145–52. http://dx.doi.org/10.23869/bphjbr.12.2.20078.

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An experiment to study the two different morphological characters of four clones of sugarcane (Saccharum spp.) panicles containing more than 50 percent of uninucleate microspore development was conducted in Tissue Culture Laboratory at Biology Faculty, Gadjah Mada University, Yogyakarta, since March until May 2006. Morphological characters of both kinds of panicles i.e. unsheated- and sheated flowers from sheat flag leaf were observed. Mean, percentage, and standard deviation from the mean value of the six different stages of microspore development e.g. tetrad, early- and late-uninucleate, early- and late-binucleate, and multinucleate or pollen grains were statistically used in this calculation. All data percentages were analyzed by variance analysis through General Linier Model Procedure, and comparisons between means of the uninucleate microspore development based on the two different morphological characters of four clones was calculated by Least Significance Difference method. Comparisons between the two different panicles characteristics in accordance with the proportion of the uninucleate microspore development, however, were analyzed by T-student procedure. All calculations were done by using SAS program of computer statistics package. Result of the research showed that: (1) the unsheated panicles were contained less than 50 percent of uninucleate (early- and late-uninucleate) microspore development; (2) the sheated panicles tend to be in high proportion of early- and late-uninucleate microspore development, and multinucleate or pollen grains, and (3) the more away of spikelets or anthers positioned in the panicle or sub-panicle, the more number or percentage of uninucleate microspores development were tend to be gradually decreased.

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Gladman, Nicholas, Yinping Jiao, Young Koung Lee, Lifang Zhang, Ratan Chopra, Michael Regulski, Gloria Burow et al. « Fertility of Pedicellate Spikelets in Sorghum Is Controlled by a Jasmonic Acid Regulatory Module ». International Journal of Molecular Sciences 20, n^o 19 (8 octobre 2019) : 4951. http://dx.doi.org/10.3390/ijms20194951.

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As in other cereal crops, the panicles of sorghum (Sorghum bicolor (L.) Moench) comprise two types of floral spikelets (grass flowers). Only sessile spikelets (SSs) are capable of producing viable grains, whereas pedicellate spikelets (PSs) cease development after initiation and eventually abort. Consequently, grain number per panicle (GNP) is lower than the total number of flowers produced per panicle. The mechanism underlying this differential fertility is not well understood. To investigate this issue, we isolated a series of ethyl methane sulfonate (EMS)-induced multiseeded (msd) mutants that result in full spikelet fertility, effectively doubling GNP. Previously, we showed that MSD1 is a TCP (Teosinte branched/Cycloidea/PCF) transcription factor that regulates jasmonic acid (JA) biosynthesis, and ultimately floral sex organ development. Here, we show that MSD2 encodes a lipoxygenase (LOX) that catalyzes the first committed step of JA biosynthesis. Further, we demonstrate that MSD1 binds to the promoters of MSD2 and other JA pathway genes. Together, these results show that a JA-induced module regulates sorghum panicle development and spikelet fertility. The findings advance our understanding of inflorescence development and could lead to new strategies for increasing GNP and grain yield in sorghum and other cereal crops.

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Li, Guan, Yichen Cheng, Man Yin, Jinyu Yang, Jiezheng Ying et Changlan Zhu. « Detection of QTLs for panicle-related traits using an indica × japonica recombinant inbred line population in rice ». PeerJ 9 (29 novembre 2021) : e12504. http://dx.doi.org/10.7717/peerj.12504.

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Background The panicle is the most important organ in rice, and all the panicle-related traits are correlated with rice grain yield. Understanding the underlying genetic mechanisms controlling panicle development is very important for improving rice production. Methods Nine panicle-related traits including heading date, panicle length, number of primary branches, number of secondary branches, number of grains per panicle, number of panicles per plant, number of filled grains per plant, seed-setting rate, and grain yield per plant were investigated. To map the quantitative trait loci (QTLs) for the nine panicle-related traits, a PCR-based genetic map with 208 markers (including 121 simple sequence repeats and 87 InDels) and a high-density linkage map with 18,194 single nucleotide polymorphism (SNP) markers were both used. Results Using a recombinant inbred line population derived from an indica variety Huanghuazhan and a japonica line Jizi 1560, a total of 110 and 112 QTLs were detected for panicle-related traits by PCR-based genetic map and by high-density linkage map, respectively. Most of the QTLs were clustered on chromosomes 1, 2, 3, 6, and 7 while no QTLs were detected on chromosome 10. Almost all the QTLs with LOD values of more than 5.0 were repeatedly detected, indicating the accuracy of the two methods and the stability of the QTL effects. No genes for panicle-related traits have been previously reported in most of these regions. QTLs found in JD1006–JD1007 and RM1148–RM5556 with high LOD and additive values deserved further research. The results of this study are beneficial for marker-assisted breeding and provide research foundation for further fine-mapping and cloning of these QTLs for panicle-related traits.

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Fraga, Thiago Isquierdo, Felipe de Campos Carmona, Ibanor Anghinoni, Silvio Aymone Genro Junior et Elio Marcolin. « Flooded rice yield as affected by levels of water salinity in different stages of its cycle ». Revista Brasileira de Ciência do Solo 34, n^o 1 (février 2010) : 175–82. http://dx.doi.org/10.1590/s0100-06832010000100018.

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Losses of productivity of flooded rice in the State of Rio Grande do Sul, Brazil, may occur in the Coastal Plains and in the Southern region due to the use of saline water from coastal rivers, ponds and the Laguna dos Patos lagoon, and the sensibility of the plants are variable according to its stage of development. The purpose of this research was to evaluate the production of rice grains and its components, spikelet sterility and the phenological development of rice at different levels of salinity in different periods of its cycle. The experiment was conducted in a greenhouse, in pots filled with 11 dm³ of an Albaqualf. The levels of salinity were 0.3 (control), 0.75, 1.5, 3.0 and 4.5 dS m-1 kept in the water layer by adding a salt solution of sodium chloride, except for the control, in different periods of rice development: tillering initiation to panicle initiation; tillering initiation to full flowering; tillering initiation to physiological maturity; panicle initiation to full flowering; panicle initiation to physiological maturity and full flowering to physiological maturity. The number of panicles per pot, the number of spikelets per panicle, the 1,000-kernel weight, the spikelet sterility, the grain yield and phenology were evaluated. All characteristics were negatively affected, in a quadratic manner, with increased salinity in all periods of rice development. Among the yield components evaluated, the one most closely related to grain yields of rice was the spikelet sterility.

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MANJARREZ-SANDOVAL, PEDRO, VÍCTOR A. GONZÁLEZ-HERNÁNDEZ, LEOPOLDO E. MENDOZA-ONOFRE et E. M. ENGLEMAN. « DROUGHT STRESS EFFECTS ON THE GRAIN YIELD AND PANICLE DEVELOPMENT OF SORGHUM ». Canadian Journal of Plant Science 69, n^o 3 (1 juillet 1989) : 631–41. http://dx.doi.org/10.4141/cjps89-079.

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Many studies have reported responses to drought stress in sorghum (Sorghum bicolor (L.) Moench) but little is known about its effects on panicle development. To determine the stage of development most susceptible to water deficiency, in terms of grain yield components, eight plants of two sorghum lines were subjected to each of 10 single, successive drought stress treatments covering the entire life cycle. In each stress treatment, water was withheld until half of the plants remained wilted at sunrise. Effects on panicle development were also studied. Single sorghum plants were grown in pots containing a 3:1 soil (Typic Argiustoll)-sand mixture in a polyethylene greenhouse at Chapingo, Mexico. Drought stress during microsporogenesis destroyed the whole panicle. Prior to this stage, drought produced abortion of the panicle-branch primordia, and a reduction of 25–55% in the number of grains per mature panicle. Later drought stress periods did not reduce the number of grains per panicle, but reduced individual grain weight by as much as 50%. Consequently, the yield was reduced by drought stress periods at all stages of panicle development before physiological maturity. Furthermore, drought stress before anthesis slowed the subsequent developmental rate of the panicle; drought stress after anthesis accelerated it. The proportion of fertile pollen grains remained above 90% in all drought stress periods. It is concluded that microsporogenesis and the milk dough stage are the most sensitive stages of sorghum panicle development to water deficits.Key words: Sorghum bicolor (L.) Moench, grain sorghum, yield components, pollen sterility, sorghum cold-tolerance, microsporogenesis

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Ramadhan, Fitrah, Willy Bayuardi Suwarno, Anggi Nindita et Dan Hajrial Aswidinnoor. « Analisis Genetik Arsitektur Malai Padi Menggunakan Dua Populasi F2 ». Jurnal Agronomi Indonesia (Indonesian Journal of Agronomy) 46, n^o 1 (26 avril 2018) : 1. http://dx.doi.org/10.24831/jai.v46i1.17265.

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Improvement of rice panicle architecture is one important objective in the development of improved new-plant-type rice varieties. Panicle architecture is directly related to yield components in rice. The aims of this study were to obtain information on inheritance pattern of panicle architecture on F2 generation and to obtain the best selected individuals. The experiment was conducted at Sawah Baru Experimental Farm Bogor, from May to October 2016. Two F2 populations derived from crosses of IPB 3S/IPB160-F-36, IPB160-F-36/IPB 5R and three genotypes of parents were used as experimental materials. A total of 208 and 204 plant samples were taken representing each of the two F2 populations and 20 plants representing the parents. Three panicles were taken randomly from each individual as observed samples. The results showed that additive gene action influenced number of primary branches in population of IPB 3S/IPB160-F-36, whereas in the population of IPB160-F-36/IPB 5R, most of the panicle architecture traits were controlled by additive gene action except for the length of primary branches. All of panicle architecture traits were controlled by relatively many genes except length of primary branches and number of grains on primary branches in the IPB 3S/IPB160-F-36 population. The panicle architecture of the two observed population was genetically varies. The heritability estimates were moderate to high. Selection could increase the mean of panicle architecture traits using either single or multiple traits simultaneously. Keywords: gene action, heritability, genetic variability, panicle traits

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Craufurd, P. Q., D. J. Flower et J. M. Peacock. « Effect of Heat and Drought Stress on Sorghum (Sorghum Bicolor). I. Panicle Development and Leaf Appearance ». Experimental Agriculture 29, n^o 1 (janvier 1993) : 61–76. http://dx.doi.org/10.1017/s001447970002041x.

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SummarySeven sorghum lines, flowering from 50 to 87 days after sowing, were subjected to early drought stress, late stress, and both early and late stress in the field during the dry season in India. Panicle initiation was delayed by 2–25 days and flowering by 1–59 days by the drought stress treatments, the greatest effect being in the treatment subjected to both early and late stress. Stress increased the period between panicle initiation and flowering by retarding the rate of panicle development; when stress was severe panicle development stopped. Upon relief of stress following irrigation, panicle development resumed at rates comparable to those in a fully irrigated control. The rate of leaf appearance was affected in a similar manner to panicle development soon after water was withheld. Rate of leaf appearance and panicle development decreased as pre-dawn leaf water potential decreased and ceased at water potentials of −0.55 and −0.7 MPa, respectively.

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Marie-Noel, Melie Feyem, Bell Martin Joseph, Tanzi Liliane, Foncha Felix, Malaa Dorothy et Djouffo Prince Salvador. « Effect of Plant Spacing on the Growth and Yield of Rainfed Rice (Oryza Sativa) in the Bimodal Rain Forest Zone of Cameroon ». Journal of Agriculture and Crops, n^o 72 (13 février 2021) : 48–59. http://dx.doi.org/10.32861/jac.72.48.59.

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A study was carried out on plant density at the experimental field of the Institute of Agricultural Research for Development (IRAD) Nkolbisson, Yaoundé to determine the appropriate spacing to improve rainfed rice production in the bimodal rainfall forest zone of Cameroon. The experiment was conducted during the main cropping seasons of 2017 and 2018. The planting spacing used were 15cm x 15cm, 20cm x 20cm, 25cm x 25cm and 30cm x 30cm giving the plant populations of 444444, 250000, 160,000 and 111,111 plants / ha respectively using two varieties (Nerica 3 and Nerica 8). The experiment was laid out in a randomized complete block design with three replications. Significant differences were observed in the growth and yield across the years. Treatments were highly significant concerning the number of days to the appearance of the first flower, the number of days to 50% flowering, and the number of days to 50 % maturity. Plants were taller with more tillers and gave higher yields in 2017 than those of 2018. The spacing significantly affected the plant height, number of tillers, and panicle length for both varieties. The interaction of spacing and variety was significant for the number of tillers per m2 and the number of seeds per panicle, however, it was not for the weight of 1000 grains and the percentage of full bales. The yield components determining yield increase were the number of panicles / m2 and the number of seeds/panicles. Nerica 3 variety gave higher yields compared to the Nerica 8, the closer the spacing, the higher the yield. There were a strong significance and positive correlation between yield, number of panicles, and the number of grain per panicle. The spacing that gives the highest number of panicle per m2 was 15 cm X 15 cm and this spacing gave good yield in the region where the study was carried out.

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Sutoro, NFN, Tintin Suhartini, Mamik Setyowati et Kurniawan R. Trijatmiko. « Keragaman Malai Anakan dan Hubungannya dengan Hasil Padi Sawah (Oryza sativa) ». Buletin Plasma Nutfah 21, n^o 1 (12 octobre 2016) : 9. http://dx.doi.org/10.21082/blpn.v21n1.2015.p9-16.

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Morpho-physiological and yield components of rice are important character that affect the crop yield potential. Seeds as a sink of crops, its yield are very much determined by the panicle yield components, one of which is various type of tillers. The purpose of the research was to study the variability of panicle types andtheir relationshipwith grain yield of rice. Thirty rice varieties/lines were planted and observed in experimental pots. The study revealed that there are differencesin total number of panicle among varieties or lines. Average number of panicle ranges from 20&ndash;50 panicle. Among varieties, there were also differences in total number of panicles grown from primary, secondary, tertiary and quarterly tillers. The number of empty seeds of the panicles increases in the order of the sequences of tiller emergence, i.e., main panicle (11%), primary (12%), secondary (12%), tertiary (16%) and quartery (22%). High yielding rice could be obtained through the development of varieties or cultivation techniques that enable the crops produce more panicle in primary and secondary tillers compare to that in tertiary and quarterly tillers. Keywords: rice, panicle, variability. AbstrakKarakter morfofisiologi dan komponen hasil merupakan karakteristik tanaman yang mempengaruhi produktivitas. Hasil biji sebagai salah satu bagian dari sink tanaman ditentukan oleh komponen hasil, di antaranya malai yang berasal dari berbagai tipe/ jenis anakan padi. Tujuan penelitian ini untuk mengetahui keragaman malai anakan dan hubungannya dengan hasil padi. Percobaan dilaksanakan dengan menanam 30 varietas/galur pada pot percobaan. Hasil analisis menunjukkan perbedaan jumlah total malai di antara varietas/galur yang diuji. Jumlah malai berkisar antara 20&ndash;50 buah. Di antara varietas yang diuji juga terdapat perbedaan yang nyata pada jumlah malai yang berasal dari anakan primer, sekunder, tersier, dan kuarter. Kehampaan gabah dari setiap jenis malai cenderung meningkat menurut urutan pemunculan malai anakan padi, dimulai dari malai tanaman induk (11%), primer (12%), sekunder (12%), tersier (16%), dan kuarter (22%). Tanaman padi yang dapat memberi hasil tinggi dapat diperoleh melalui perakitan varietas atau teknik budi daya yang dapat menghasilkan terutama malai anakan primer dan sekunder yang relatif banyak dan sedikit atau tanpa anakan tersier dan kuarter.

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Mohapatra, Pravat Kumar, Pradeep Kumar Naik et Rajesh Patel. « Ethylene inhibitors improve dry matter partitioning and development of late flowering spikelets on rice panicles ». Functional Plant Biology 27, n^o 4 (2000) : 311. http://dx.doi.org/10.1071/pp99057.

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Primary branch development of the rice panicle was in the order of a basipetal sequence from the top to the bottom at the time of anthesis. Delayed development of spikelets on the proximal branches of the panicle resulted in reduced grain filling. Two experiments were carried out to manipulate growth and development of the proximal spikelets with exogenous application of chemicals regulating formation or action of ethylene. In the first experiment, inhibitors of ethylene synthesis (cobalt) and action (silver) improved grain biomass and specific gravity of the basal spikelets, while 2-chloroethylphosphonic acid (CEPA) depressed these parameters significantly. In the second experiment, the ethylene synthesis inhibitor 1-aminoethoxyvinylglycine (AVG) promoted spikelet development on the basal primary branches and improved their survival and grain biomass. On the contrary, the ethylene precursor 1-aminocyclopropane-1- carboxylic acid (ACC) inhibited growth and development of these spikelets. The action of AVG was reversed when ACC was applied in combination with AVG. In both experiments, the chemicals did not influence growth and development of the superior spikelets on the apical primary branches of the panicle. Depression of growth and development by CEPA or ACC coincided with a concomitant rise in soluble carbohydrate concentration of the spikelets, whereas treatments with ethylene inhibitors decreased the concentration of the materials. The role of ethylene in metabolic dominance of the apical spikelets and its impact on grain yield of rice panicles is discussed.

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Shynkaruk, L. « Efficacy of funcicides in maize growing ». Karantin i zahist roslin, n^o 1 (27 avril 2022) : 17–20. http://dx.doi.org/10.36495/2312-0614.2022.1.17-20.

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Goal. To determine the technical efficiency of fungicidal treatments against helminthosporiosis, rust and fusarium ear rot in the conditions of the western forest-steppe of Ukraine. Methods. Field. The research scheme included 13 variants with different amounts of fungicidal treatments. The following fungicides were used in the experiments: Abacus e.c. (epoxiconazole 62.5 l/ha + pyraclostrobin 62.5 l/ ha), Coronet 300 SC (trifloxystrobin 100 g/l + tebuconazole 200 g /l), Custodia CS (tebuconazole 200 g/l + azoxystrobin 120 g/l), Acanto KS (picoxystrobin — 250 g/l. Records of diseases were performed according to generally accepted methods in the phase of wax ripeness. Results. Studies have shown that fungicidal treatments reduce the development of helminthosporiosis by 14.9—25.9%, rust — by 4.0—19.4% and fusarium ear rot by 3.2—6.3%. The weighted average development of maize diseases depended on the period of application and the amount of fungicidal sprays. Among the one-time treatments, the lowest level of disease development was when spraying in the phase of panicle ejection, among double treatments — 10 leaves and panicle ejection. Three uses of fungicides in the phase of 10 leaves, shedding of panicles and after flowering reduced the development of helminthosporiosis to 4.4%, rust — to 3.5%, fusarium ear rot — to 1.2%. The highest level of protection was obtained in the variant of four preparations in the phase of 10 leaves, ejection of panicles, after flowering and grain filling, where the development of helminthosporiosis was 4.4%, rust — 2.9%, fusarium ear rot — 1.1%. The technical efficiency of the studied drugs increased with increasing number of fungicidal treatments and was the highest in the variant of four applications of fungicides, which is 86.6% against helminthosporiosis, 87.0% against rust and 85.5% against fusarium ear rot. Conclusions. The technical effectiveness of fungicides depends on the period of application of the drug and increases with an increase in the number of treatments. High technical efficiency was noted in the variant of the three-time introduction of fungicides in the phase of 10 leaves, throwing out the panicle and after flowering. The highest efficiency is in the variant of the four-time introduction of fungicides in the phase of 10 leaves, throwing out the panicle, after flowering and filling the grain.

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Krinski, Diones, et Luís Amilton Foerster. « Quantitative and qualitative damage caused by Oebalus poecilus (Hemiptera, Pentatomidae) to upland rice cultivated in new agricultural frontier of the Amazon rainforest (Brazil) ». Ciência e Agrotecnologia 41, n^o 3 (juin 2017) : 300–311. http://dx.doi.org/10.1590/1413-70542017413036816.

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ABSTRACT Oebalus poecilus (Dallas 1851) is one of the stink bug species of great economic importance for rice producers in Brazil of irrigated, flood and upland cropping systems. These pentatomids are known as stink bugs of panicles, because both nymphs and adults feed mainly on panicles. Stink bug attacks result in pecky (spots) seeds, lower mass, germinative reduction and deformed grains. Bearing these factors in mind, the aim of this study was to evaluate the quantitative and qualitative losses in commercial cultivars of upland rice (Cambará variety), submitted to different population levels of stink bugs of panicles, O. poecilus, at different reproductive growth stages. The results show that in upland rice (Cambará variety), the rice grains are susceptible to quantitative (number and weight) and qualitative (pecky, atrophy, chalky and broken grains) damage during all panicle development. However, when the insects feed during anthesis/caryopsis and milky stage cause significantly greater percentage of empty grains (up to 83%) than when they feed of grains during later phases of panicle development. This characteristic was also observed for the reduction in grain weight. This information may benefit producers and other researchers, allowing them to focus on the monitoring efforts of O. poecilus in most susceptible phases of the attack of this insect. This will enable decision-making about what control measures should be taken, and when, in order to control stink bugs of panicles.

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Menzel, CM, ML Carseldine et DR Simpson. « Crop development and leaf nitrogen in lychee in subtropical Queensland ». Australian Journal of Experimental Agriculture 28, n^o 6 (1988) : 793. http://dx.doi.org/10.1071/ea9880793.

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Heaviest flowering of 6-9-year-old lychee trees (Litchi chinensis cv. Tai So) over 3 seasons in subtropical Queensland (lat. 27�S.) was associated with a growth check in the terminal shoots prior to panicle emergence (May-June). Leaf nitrogen was the main factor controlling the level of flushing before panicle emergence. Flushing was active (on >40% of terminal branches) when leaf nitrogen concentration exceeded 1.85% N in April. These results suggest that flowering of lychee in subtropical environments where heavy rain precedes panicle emergence in autumn can be promoted by restricting leaf nitrogen levels prior to panicle emergence below 1.75-1.85% N to reduce vegetative flushing. Studies on the seasonal pattern of leaf nitrogen showed that the period during flowering to just after fruit set was the most stable for sampling for leaf nitrogen.

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Fraser, Joanna, et Eric G. Kokko. « Panicle, spikelet, and floret development in orchardgrass (Dactylis glomerata) ». Canadian Journal of Botany 71, n^o 4 (1 avril 1993) : 523–32. http://dx.doi.org/10.1139/b93-058.

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The initial stages of panicle, spikelet, and floret development in field-grown 'Kay' orchardgrass were examined using scanning electron microscopy. Spikelets arose from a complex multilevelled sequence of initiation from branch apices. Spikelets developed indirectly in a two-tiered progression: (i) an acropetal and basipetal sequence of first order, second-order, and third-order inflorescence apices, and (ii) an acropetal development within subclusters of higher-order lateral branch inflorescence apices. The panicle had the unique feature of dorsiventrality as well as bilateral symmetry. The basal apex from first-order, second-order, or third-order apices developed on the same side of the main axis as the first-order apex. The two glumes subtending each spikelet primordium developed alternately and acropetally. Development and initiation of florets within spikelets was basipetal within the panicle, basipetal within clusters and subclusters of spikelets on lateral branches, and acropetal within spikelets. Within florets, paleas developed later than lemmas. Key words: Dactylis glomerata, cocksfoot, scanning electron microscopy, development, panicle.

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Hasan, MJ, Umma Kulsum, MMH Rahman, MMH Chowdhury et AZMKA Chowdhury. « Genetic diversity analysis of parental lines for hybrid development in rice (Oryza sativa L.) ». Bangladesh Journal of Agricultural Research 37, n^o 4 (2 avril 2013) : 617–24. http://dx.doi.org/10.3329/bjar.v37i4.14386.

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Genetic divergence of 40 parental lines comprising 30 restorer and 10 maintainer lines were studied through Mohalanobis's D2 and principal component analysis for eleven characters. Genotypes were grouped into five different clusters. Cluster V comprised maximum number of genotypes (thirteen) followed by cluster I and II. The inter-cluster distance was maximum between clusters I and V (13.495) indicating wide genetic diversity between these two clusters followed by the distance between cluster I and 11 (9.489), cluster IV, and cluster V (8.969) and cluster I and cluster III (8.039). The minimum inter-cluster distance was observed between cluster II and cluster III (3.034) followed by cluster 111 and cluster IV (3.834) and cluster II and cluster V (4.945) indicating that the genotypes of these clusters were genetically close. The intra cluster distance in the entire five clusters was more or less low which indicated that the genotypes within the same cluster were closely related. Among the characters panicle weight contributed most for divergence in the studied parental lines. Difference in cluster means existed for almost all the characters studied. Highest mean value for number of effective tillers (7.8), days to 50% flowering (95.5), panicles/m2 (192.6), panicle weight (2.9), spikelet fertility (84.8), number of grains/panicle (177.8), days to maturity (123.6), and grain yield/plot (1065.5) were observed in cluster I indicated the parental lines fallen in this cluster having the genetic potentiality to contribute better for yield maximization of hybrid rice. DOI: http://dx.doi.org/10.3329/bjar.v37i4.14386 Bangladesh J. Agril. Res. 37(4): 617-624, December 2012

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Liu, Jiajun, Xi’an Shi, Zhongyuan Chang, Yanfeng Ding et Chengqiang Ding. « Auxin Efflux Transporters OsPIN1c and OsPIN1d Function Redundantly in Regulating Rice (Oryza sativa L.) Panicle Development ». Plant and Cell Physiology 63, n^o 3 (9 décembre 2021) : 305–16. http://dx.doi.org/10.1093/pcp/pcab172.

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Abstract The essential role of auxin in plant growth and development is well known. Pathways related to auxin synthesis, transport and signaling have been extensively studied in recent years, and the PIN-FORMED (PIN) protein family has been identified as being pivotal for polar auxin transport and distribution. However, research focused on the functional characterization of PIN proteins in rice is still lacking. In this study, we investigated the expression and function of OsPIN1c and OsPIN1d in the japonica rice variety (Nipponbare) using gene knockout and high-throughput RNA sequencing analysis. The results showed that OsPIN1c and OsPIN1d were mainly expressed in young panicles and exhibited a redundant function. Furthermore, OsPIN1c or OsPIN1d loss-of-function mutants presented a mild phenotype compared with the wild type. However, in addition to significantly decreased plant height and tiller number, panicle development was severely disrupted in double-mutant lines of OsPIN1c and OsPIN1d. Severe defects included smaller inflorescence meristem and panicle sizes, fewer primary branches, elongated bract leaves, non-degraded hair and no spikelet growth. Interestingly, ospin1cd-3, a double-mutant line with functional retention of OsPIN1d, showed milder defects than those observed in other mutants. Additionally, several critical regulators of reproductive development, such as OsPID, LAX1, OsMADS1 and OsSPL14/IPA1, were differentially expressed in ospin1c-1 ospin1d-1, supporting the hypothesis that OsPIN1c and OsPIN1d are involved in regulating panicle development. Therefore, this study provides novel insights into the auxin pathways that regulate plant reproductive development in monocots.

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Kuzenko, M. V., et V. I. Kuzenko. « Influence of morphological characteristics of stem and panicle length on wintering oat lodging resistance ». New Technologies 16, n^o 5 (31 décembre 2020) : 63–70. http://dx.doi.org/10.47370/2072-0920-2020-16-5-63-70.

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The article presents the results of investigating morphological parameters of a stem and a panicle of wintering oat varieties and hybrid populations of the nursery of competitive variety trial and Avena fatua (L.) field weed species. The research has been carried out in order to identify differences in morphological characteristics of cultivated and weed-field types of oats, as well as to search for economically useful characteristics for practical use in breeding. The research focuses on lodging resistance as one of the significant economically valuable signs of increasing wintering oat productivity. The studied samples have been analyzed according to plant height, number and length of internodes, and panicle length. The role of the length of internodes and panicles in the formation of the height of both species has been determined. Differences in the length of internodes have been revealed when compared with the standard and Avena fatua (L.). The relationship between internodes and panicles with height has been shown, as well as the dependence of the developed length of each internode between the nodes of the plant itself. The performed correlation analysis has revealed the presence of a high positive relationship between the height of wintering oat plants and the length of the fifth internode (0,61) and panicle (0,91). The presence of these connections indicates the need for forms of oats with a short fifth internode and a panicle in order to increase the resistance to lodging in crosses. The use of the results of morphological analysis complements the visual assessment of lodging resistance, makes it possible to characterize the parental forms used in the hybridization process, and to promote the accelerated development of varieties resistant to stem lodging.

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Zhang, Jinshan, Zhenyu Zhou, Jinjuan Bai, Xiaoping Tao, Ling Wang, Hui Zhang et Jian-Kang Zhu. « Disruption of MIR396e and MIR396f improves rice yield under nitrogen-deficient conditions ». National Science Review 7, n^o 1 (27 septembre 2019) : 102–12. http://dx.doi.org/10.1093/nsr/nwz142.

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Abstract The microRNA miR396 directly represses GROWTH-REGULATING FACTORs (OsGRFs) and has been implicated in regulating rice yield and in nitrogen assimilation. Overexpressing the miR396 targets OsGRF4 and OsGRF6 improves rice yield via increased grain size and panicle branching, respectively. Here, we used CRISPR/Cas9 to assess the function of miR396 genes in rice. Knockout of MIR396ef (MIR396e and MIR396f), but not other isoforms, enhanced both grain size and panicle branching, resulting in increased grain yield. Importantly, under nitrogen-deficient conditions, mir396ef mutants showed an even higher relative increase in grain yield as well as elevated above-ground biomass. Furthermore, we identified OsGRF8 as a new target of miR396, in addition to the known targets OsGRF4 and OsGRF6. Disruption of the miR396-targeting site in OsGRF8 was sufficient to both enlarge grain size and elongate panicles. Our results suggest that rice-seed and panicle development are regulated by miR396ef-GRF4/6/8-GIF1/2/3 modules and that miR396ef are promising targets of genome editing for breeding environmentally friendly rice varieties that require less nitrogen fertilization.

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KHAN, W. U., S. M. A. SHAH, H. ULLAH, I. H. KHALIL, S. A. JADOON et D. WANG. « DEVELOPMENT OF RICE GERMPLASM BASED ON GENETIC VARIABILITY IN F5 SEGREGATING POPULATIONS ». SABRAO Journal of Breeding and Genetics 54, n^o 5 (31 décembre 2022) : 993–1003. http://dx.doi.org/10.54910/sabrao2022.54.5.3.

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Water scarcity is a global dilemma, and rice crop needs plenty of water for optimum growth and yield. In the current climate change scenario, developing a broad-based gene pool of rice to help the crop breeders develop high-yielding cultivars needs dire action. This study assessed the genetic variation among 10 diversified parents and their 15 F5 populations developed under limited water supply for various morphological traits. Parents and F5 populations showed significant differences at 5% and 1% for most of the studied maturity and yield traits. F5 population ‘Dokri-Basmati/DR-92’ exhibited earliest for days to heading (93) with the highest culm length (85.5 cm). Maximum flag leaf area (34.67 cm2) resulted for the F5 population ‘DR-83/NIAB-IRRI-8.’ On the other hand, the F5 population ‘DR-83/DR-92’ excelled in performance for the number of primary branches panicle-1 (11). F5 population ‘IR-8/NIAB-IRRI-9’ displayed the longest panicle (28.70 cm) with the highest number of secondary branches panicle-1 (38). Three of the F5 populations ‘DR-92/DR-83,’ ‘DR-83/NIAB-IRRI-8,’ and ‘NIAB-IRRI-9/IR-8,’ displayed maximum heritability for panicle length (0.82), the number of primary branches (0.80), and secondary branches panicle-1 (0.94), respectively, offering the prospects for development of potentially high-yielding variety. The highest genetic advance for panicle length (9.87%) emerged from the F5 population ‘DR-92/DR-83,’ which also had the highest heritability for this trait. F5 population ‘DR-83/DR-92’ manifested maximum genetic advance (3.32%) for primary branches panicle-1, while ‘NIAB-IRRI-9/IR-8’ revealed the highest genetic advance (6.26%) for secondary branches panicle-1. Both of these populations may be suitable for developing the spreading type of rice germplasm with the potential water stress. F5 populations displayed differential responses for the studied traits, with none of the segregating populations excelling for studied maturity and yield traits. However, the germplasm pool created can serve as a better collection for improving existing populations from a production traits perspective under water-stress conditions or developing new cultivars focusing these traits for the target water stress region(s).

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Panigrahi, Rashmi, Ekamber Kariali, Binay Bhusan Panda, Tanguy Lafarge et Pravat Kumar Mohapatra. « Controlling the trade-off between spikelet number and grain filling : the hierarchy of starch synthesis in spikelets of rice panicle in relation to hormone dynamics ». Functional Plant Biology 46, n^o 6 (2019) : 507. http://dx.doi.org/10.1071/fp18153.

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The advent of dwarf statured rice varieties enabled a major breakthrough in yield and production, but raising the ceiling of genetically determined yield potential even further has been the breeding priority. Grain filling is asynchronous in the rice panicle; the inferior spikelets particularly on secondary branches of the basal part do not produce grains of a quality suitable for human consumption. Of the various strategies being considered, the control of ethylene production at anthesis has been a valuable route to potentially enhance genetic yield level of rice. The physiology underlying spikelet development has revealed spikelet position-specific ethylene levels determine the extent of grain filling, with higher levels resulting in ill-developed spikelet embodying poor endosperm starch content. To break the yield barrier, breeders have increased spikelet number per panicle in new large-panicle rice plants. However, the advantage of panicles with numerous spikelets has not resulted in enhanced yield because of poor filling of inferior spikelets. High spikelet number stimulates ethylene production and downgrading of starch synthesis, suggesting a trade-off between spikelet number and grain filling. High ethylene production in inferior spikelets suppresses expression of genes encoding endosperm starch synthesising enzymes. Hence, ethylene could be a retrograde signal that dictates the transcriptome dynamics for the cross talk between spikelet number and grain filling in the rice panicle, so attenuation of its activity may provide a solution to the problem of poor grain filling in large-panicle rice. This physiological linkage that reduces starch biosynthesis of inferior kernels is not genetically constitutive and amenable for modification through chemical, biotechnological, surgical and allelic manipulations. Studies on plant genotypes with different panicle architecture have opened up possibilities of selectively improving starch biosynthesis of inferior spikelets and thereby increasing grain yield through a physiological route.

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Panigrahi, Rashmi, Ekamber Kariali, Binay Bhusan Panda, Tanguy Lafarge et Pravat Kumar Mohapatra. « Corrigendum to : Controlling the trade-off between spikelet number and grain filling : the hierarchy of starch synthesis in spikelets of rice panicle in relation to hormone dynamics ». Functional Plant Biology 46, n^o 6 (2019) : 595. http://dx.doi.org/10.1071/fp18153_co.

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The advent of dwarf statured rice varieties enabled a major breakthrough in yield and production, but raising the ceiling of genetically determined yield potential even further has been the breeding priority. Grain filling is asynchronous in the rice panicle; the inferior spikelets particularly on secondary branches of the basal part do not produce grains of a quality suitable for human consumption. Of the various strategies being considered, the control of ethylene production at anthesis has been a valuable route to potentially enhance genetic yield level of rice. The physiology underlying spikelet development has revealed spikelet position-specific ethylene levels determine the extent of grain filling, with higher levels resulting in ill-developed spikelet embodying poor endosperm starch content. To break the yield barrier, breeders have increased spikelet number per panicle in new large-panicle rice plants. However, the advantage of panicles with numerous spikelets has not resulted in enhanced yield because of poor filling of inferior spikelets. High spikelet number stimulates ethylene production and downgrading of starch synthesis, suggesting a trade-off between spikelet number and grain filling. High ethylene production in inferior spikelets suppresses expression of genes encoding endosperm starch synthesising enzymes. Hence, ethylene could be a retrograde signal that dictates the transcriptome dynamics for the cross talk between spikelet number and grain filling in the rice panicle, so attenuation of its activity may provide a solution to the problem of poor grain filling in large-panicle rice. This physiological linkage that reduces starch biosynthesis of inferior kernels is not genetically constitutive and amenable for modification through chemical, biotechnological, surgical and allelic manipulations. Studies on plant genotypes with different panicle architecture have opened up possibilities of selectively improving starch biosynthesis of inferior spikelets and thereby increasing grain yield through a physiological route.

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Carpenter, Judith L., et Herbert J. Hopen. « A Comparison of the Biology of Wild and Cultivated Proso Millet (Panicum miliaceum) ». Weed Science 33, n^o 6 (novembre 1985) : 795–99. http://dx.doi.org/10.1017/s0043174500083363.

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Wild and cultivated proso millet (Panicum miliaceumL. ♯ PANMI) showed increased height and dry mass with increasing photoperiod and flowered under all photoperiods. Increasing planting density decreased height and dry mass and slowed seedhead development in both types. Shading increased plant height and decreased dry mass of both millets and increased germination compared to unshaded treatments. Planting date did not affect germination of freshly collected seed of either millet. Wild proso millet seed had a low germination rate until 8 weeks after panicle emergence, and the rate increased to 22% after 10 weeks. Germination of cultivated proso millet seed was low for 5 weeks after panicle emergence and increased to 92% after 10 weeks.

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Rood, Stewart B., Darla M. Bruns et Susan J. Smienk. « Gibberellins and sorghum development ». Canadian Journal of Botany 66, n^o 6 (1 juin 1988) : 1101–6. http://dx.doi.org/10.1139/b88-157.

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Sorghum (Sorghum bicolor (L.) Moench) hybrids adapted for grain (cv. Northrup King X8102) or forage production (cv. Pride PF70) were grown in field trials at Lethbridge, Alta., Canada, and shoot cylinders containing the apical meristems were harvested at various developmental stages for analyses of endogenous gibberellin-like (GA-like) substances. Extracts were purified and chromatographed on sequential SiO2 partition columns and C18 reversed-phase high-performance liquid chromatography, and GA-like substances were detected and quantified by the cv. Tan-ginbozu dwarf rice microdroop assay. Concentrations of GA-like substances in the shoots were higher during vegetative growth than during shoot elongation or panicle elongation and the pattern of declining concentration of GA-like substances was observed for both hybrids over both field seasons. The qualitative distribution of GA-like substances was generally similar across hybrids and developmental stages, with a GA19-like substance accounting for about 60% of the total GA-like activity (GA19 is a native GA of sorghum). The exogenous application of GA3 promoted height growth and inhibited tillering, with maximal effects occurring when application was early, during rapid vegetative growth. Applications of GA3 subsequent to panicle initiation promoted panicle elongation but did not alter the time of anthesis. These results on endogenous GA concentration and response to exogenous GA3 application suggest a role for endogenous GAs in the control of shoot growth and development in sorghum.

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Ali, Asif, Tingkai Wu, Zhengjun Xu, Asad Riaz, Ahmad M. Alqudah, Muhammad Zafar Iqbal, Hongyu Zhang et al. « Phytohormones and Transcriptome Analyses Revealed the Dynamics Involved in Spikelet Abortion and Inflorescence Development in Rice ». International Journal of Molecular Sciences 23, n^o 14 (17 juillet 2022) : 7887. http://dx.doi.org/10.3390/ijms23147887.

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Panicle degeneration, sometimes known as abortion, causes heavy losses in grain yield. However, the mechanism of naturally occurring panicle abortion is still elusive. In a previous study, we characterized a mutant, apical panicle abortion1331 (apa1331), exhibiting abortion in apical spikelets starting from the 6 cm stage of panicle development. In this study, we have quantified the five phytohormones, gibberellins (GA), auxins (IAA), abscisic acid (ABA), cytokinins (CTK), and brassinosteroids (BR), in the lower, middle, and upper parts of apa1331 and compared these with those exhibited in its wild type (WT). In apa331, the lower and middle parts of the panicle showed contrasting concentrations of all studied phytohormones, but highly significant changes in IAA and ABA, compared to the upper part of the panicle. A comparative transcriptome of apa1331 and WT apical spikelets was performed to explore genes causing the physiological basis of spikelet abortion. The differential expression analysis revealed a significant downregulation and upregulation of 1587 and 978 genes, respectively. Hierarchical clustering of differentially expressed genes (DEGs) revealed the correlation of gene ontology (GO) terms associated with antioxidant activity, peroxidase activity, and oxidoreductase activity. KEGG pathway analysis using parametric gene set enrichment analysis (PGSEA) revealed the downregulation of the biological processes, including cell wall polysaccharides and fatty acids derivatives, in apa1331 compared to its WT. Based on fold change (FC) value and high variation in expression during late inflorescence, early inflorescence, and antherdevelopment, we predicted a list of novel genes, which presumably can be the potential targets of inflorescence development. Our study not only provides novel insights into the role of the physiological dynamics involved in panicle abortion, but also highlights the potential targets involved in reproductive development.

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Korotenko, Tatyana, Semen Yurchenko et Lyubov Esaulova. « Plant productivity parameters in rice varieties with different type of panicles and their variability ». E3S Web of Conferences 285 (2021) : 02031. http://dx.doi.org/10.1051/e3sconf/202128502031.

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To increase rice yield, scientists are considering the possibility of changing the morphological parameters of plants. At the same time, there are not enough attempts in Russia to analyze the yield potential of varieties with different panicle architectonics. The purpose of our research was a comparative analysis of rice varieties differing in panicle morphotype, by the formation of productivity elements. In the ecological conditions of the south of Russia, in 2019-2020, a series of field experiments were carried out with 24 Oryza sativa L. varieties under conditions of artificial irrigation. The results of assessing the elements of plant productivity and biological productivity of varieties differentiated into 6 groups according to the panicle type and grown on plots 1x12 m are presented. The present study showed that in the rice-growing zone of Krasnodar region, varieties with a compact inclined and slightly spreading panicle had an advantage in achieving high productivity. However, the stability of quantitative traits was exhibited by varieties with spreading panicles of the drooping type. Correlation analysis confirmed: the longer the panicle, the more spreading it is and the less sterile spikelets are formed on it. Along with other researchers, we revealed significant differences in yield between japonica and Indica varieties. Due to the cultivation of varieties under equal conditions, the variation in biological yield from 778 to 1203 g / m2 can be explained by their genotypic characteristics. For the sustainable development of rice growing in the region, our studies emphasize the importance of the diversity of varieties of various morphotypes with high potential and stability of productivity elements and provide useful information for breeding.

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Jalil, MA, IJ Shelley, MHR Pramanik et MA Karim. « Effect of transplanting times on pollen and spikelet sterility, growth and yield of aman rice ». Progressive Agriculture 27, n^o 4 (10 avril 2017) : 400–408. http://dx.doi.org/10.3329/pa.v27i4.32119.

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A field experiment was conducted to study the effect of planting dates on pollen/spikelet sterility, grain development and yield of hybrid rice in T. Aman season. The two varieties: Heera-4 (hybrid) and BINAdhan-7 (inbred) were transplanted on five consecutive dates at fifteen days interval viz. 15 July, 30 July, 15 August, 30 August and 15 September of 2011. The effect of variety and transplanting date showed significant variation in pollen sterility, grain growth & development, panicle length, filled grains panicle-1, spikelet sterility and grain yield. Pollen sterility was the highest in Heera-4 (>80%) consequently spikelet sterility for transplanting on 15 July while transplanting on 30 July low pollen sterility consequently spikelet sterility. Both early or late transplanting affected grain growth and development, enhanced pollen sterility as well as spikelet sterility and reduced grain yield. Late transplanting (30 August and 15 September) significantly reduced panicle length and filled grains panicle-1. Transplanting on 30 July gave low pollen sterility as well as spikelet sterility, high panicle length and high filled grains panicle-1 consequently greater grain yield in the varieties.Progressive Agriculture 27 (4): 400-408, 2016

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Boyle, Roger, Fiona Corke et Catherine Howarth. « Image-based estimation of oat panicle development using local texture patterns ». Functional Plant Biology 42, n^o 5 (2015) : 433. http://dx.doi.org/10.1071/fp14056.

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Flowering time varies between and within species, profoundly influencing reproductive fitness in wild plants and productivity in crop plants. The time of flowering, therefore, is an important statistic that is regularly collected as part of breeding programs and phenotyping experiments to facilitate comparison of genotypes and treatments. Its automatic detection would be highly desirable. We present significant progress on an approach to this problem in oats (Avena sativa L.), an underdeveloped cereal crop of increasing importance. Making use of the many thousands of images of oat plants we have available, spanning different genotypes and treatments, we observe that during flowering, panicles (the flowering structures) betray particular intensity patterns that give an identifiable texture that is distinctive and discriminatory with respect to the main plant body and can be used to determine the time of flowering. This texture can be located by a filter, trained as a form of local pattern. This training phase identifies the best parameters of such a filter, which usefully discovers the scale of the panicle spikelets. The results demonstrate the success of the filter. We proceed to suggest and evaluate an approach to using the filter as a growth stage detector. Preliminary results show very good correspondence with hand-measured ground truth, and are amenable to improvement in several ways. Future work will build on this initial success and will go on to locate fully mature panicles, which have a different appearance, and assess whether this approach can be extended to a broader range of plants.

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Gutorova, O. V., S. A. Zaitsev, P. A. Matyushin, A. Yu Lyovkina et D. D. Babushkin. « Evaluation of experimental corn hybrids on the development of morphometric parameters ». IOP Conference Series : Earth and Environmental Science 1045, n^o 1 (1 juin 2022) : 012012. http://dx.doi.org/10.1088/1755-1315/1045/1/012012.

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Abstract The article presents the results of the study of new hybrid combinations of rediploid maize lines obtained by the diallelic scheme of crossing. The experiment involved simple hybrids of six homozygous lines. The degree of manifestation of heterosis according to the main morphometric parameters of the plant (stem length, ear height, panicle length, stem diameter), as well as the combinative ability of lines and components of genetic dispersion, was revealed. The ways of possible use of lines and hybrids in the breeding process are noted - for tall stature, resistance to lodging, manufacturability. The influence of overdominance in the manifestation of the length of the panicle and the diameter of the stem and the predominance of additive effects in the formation of the height of the ear were noted. Analysis of the components made it possible to identify the number of genes or groups of genes that influenced the manifestation of traits in 2021 (stem length - 1-2, cob height - 2-3, panicle length - 1-2, stem diameter - 2-3). A significant influence of cultivation conditions on the manifestation of the length of the stem, the height of the cob, the length of the panicle, and the diameter of the stem was noted.1.

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Mahalakshmi, V., et F. R. Bidinger. « Water deficit during panicle development in pearl millet : yield compensation by tillers ». Journal of Agricultural Science 106, n^o 1 (février 1986) : 113–19. http://dx.doi.org/10.1017/s0021859600061815.

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SUMMARYWater deficit during the panicle development stage reduced the grain yield of the main shoot panicle of pearl millet but this loss was compensated by increased grain yield of the tillers. The potential extent of compensation in grain yield components by tillers was investigated by removing the main shoot at panicle initiation (PI) and flowering stages respectively, for both irrigated and water-stressed plants. Grain yield loss by removal of the main shoot of plants at PI was fully compensated by tiller grain yield in both the irrigated and water-stressed plants. The compensation was, however, only partial when the main shoot was removed at flowering. The compensation for the grain yield loss in the main shoot due to either water stress or removal was through an increase in number of grains on the tillers. This increase was due to an increase in the number of productive tillers in the case of water stress and to both an increase in the number of productive tillers and an increase in the number of grains per panicle in the case of main shoot removal. This compensatory mechanism by tillers plays an important role in overcoming the effects of pre-flowering water stress damage to the main shoot.

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Senanayake, N., R. E. L. Naylor, S. K. De Datta et W. J. Thomson. « Variation in development of contrasting rice cultivars ». Journal of Agricultural Science 123, n^o 1 (août 1994) : 35–39. http://dx.doi.org/10.1017/s0021859600067745.

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SummaryExperiments were conducted in glasshouses at IRRI, Philippines, during 1987 and 1988 to identify varietal differences in apical development using six rice cultivars having extreme characters; Jirasar 280 (early senescence), Neo-Dunghan 1 (late senescence), Macunting (small seeds), ABB (large seeds), C12474–1 (long culm), and B581–A6–458 (short culm); and five cultivars, IR20, IR22, IR34, IR54, IR64, of the same growth duration.The length of time from physiological panicle initiation (PI) to flowering varied from 25 to 50 days. The onset of physiological PI occurred when the fourth penultimate leaf was fully exserted. The visual panicle initiation stage (VPI) coincided with spikelet differentiation in all cultivars. Nitrogen top-dressing at 55–57 days before the anticipated maturity date (the present N management recommendation) did not coincide with the actual panicle initiation stage in any of the cultivars and the major yield determinants (i.e. the primary and secondary branches) therefore differentiated in conditions of internal nitrogen shortage. Spikelet abortion took place both before and after flowering. Reduction of pre-flowering abortion is important in increasing rice grain yields and could be achieved by improved N management. It is important to recognise cultivar differences and periods of loss of potential yield in developing efficient N management protocols.

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Chitanda, Lovemore, Munyaradzi Mativavarira, Pepukai Manjeru, Kyung-Ho Kang, Jean K. Nzuma, Trymore Kamunhukamwe, Tendai A. Hove et Leonard Madzingaidzo. « Performance of Doubled Haploid Elite Rice (Oryza sativa L.) Germplasm for Grain Yield and Associated Traits in Harare, Zimbabwe ». Advances in Agriculture 2022 (9 avril 2022) : 1–9. http://dx.doi.org/10.1155/2022/7393896.

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A field experiment was conducted in 2018/2019 growing season at the Scientific Industrial Research and Development Center under irrigated conditions using the simple alpha lattice (7 ∗ 7) design, with three replications. The objective of the study was to determine the performance of 44 elite rice lines that were selected and shared from elite doubled haploid germplasm and five cultivars were used as checks. All evaluated genotypes exhibited significant variation in the traits measured except for number of grains/panicle, total tillers/plant, and effective tillers/plant. Elite line 70462 was found to be the highest yielding, with yield advantage of 66% over the high yielding local check (Nerica 7). High values for broad sense heritability were recorded for days to 50% heading, panicle length, culm length, number of filled grains/panicle, 1000-grain weight, grain length, grain shape, and grain yield and indicated lesser influence of environment in expression of these traits, hence amenable to simple selection. Correlation analysis revealed that grain yield manifested significantly positive correlation with filled grains/panicle contributing the highest correlation (r = 0.784), followed by culm length (r = 0.605), spikelet fertility/panicle (r = 0.677), grain length (r = 0.551), 1000-grain weight (r = 0.518), panicle length (r = 0.449), and number of grains/panicle (r = 0.328). Based on grain yield, number of filled grains/panicle and spikelet fertility/panicle, panicle length, and earliness, lines 70462, 60143, 70383, Arica 3, Sahel 177, 6040, 70537, 60409, and 70476 had the best performance. Selection of these traits would be more effective for yield improvement in rice and these promising lines could be used in the varietal development and can be tested in multilocational trials and on-farm trials in Zimbabwe with the possibility of release and commercialization.

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Gunawardena, T. A., S. Fukai et F. P. C. Blamey. « Low temperature induced spikelet sterility in rice. II. Effects of panicle and root temperatures ». Australian Journal of Agricultural Research 54, n^o 10 (2003) : 947. http://dx.doi.org/10.1071/ar03076.

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Low temperatures impose restrictions on rice (Oryza sativa L.) production at high latitudes. This study is related to low temperature damage that can arise mid-season during the panicle development phase. The objective of this study was to determine whether low temperature experienced by the root, panicle, or foliage is responsible for increased spikelet sterility. In temperature-controlled glasshouse experiments, water depth, and water and air temperatures, were changed independently to investigate the effects of low temperature in the root, panicle, and foliage during microspore development on spikelet sterility. The total number of pollen and number of engorged pollen grains per anther, and the number of intercepted and germinated pollen grains per stigma, were measured. Spikelet sterility was then analysed in relation to the total number of pollen grains per spikelet and the efficiency with which these pollen grains became engorged, were intercepted by the stigma, germinated, and were involved in fertilisation. There was a significant combined effect of average minimum panicle and root temperatures on spikelet sterility that accounted for 86% of the variation in spikelet sterility. Total number of pollen grains per anther was reduced by low panicle temperature, but not by low root temperature. Whereas engorgement efficiency (the percentage of pollen grains that were engorged) was determined by both root and panicle temperature, germination efficiency (the percentage of germinated pollen grains relative to the number of engorged pollen grains intercepted by the stigma) was determined only by root temperature. Interception efficiency (i.e. percentage of engorged pollen grains intercepted by the stigma), however, was not affected by either root or panicle temperature. Engorgement efficiency was the dominant factor explaining the variation in spikelet sterility. It is concluded that both panicle and root temperature affect spikelet sterility in rice when the plant encounters low temperatures during the microspore development stage.

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Carpenter, Judith L., et Herbert J. Hopen. « Wild and Cultivated Proso Millet Responses to Plant Growth Regulators ». HortScience 20, n^o 5 (octobre 1985) : 942–44. http://dx.doi.org/10.21273/hortsci.20.5.942.

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Abstract The effect of postemergence applications of mefluidide at 0, 0.14, 0.28, and 0.56 kg/ha or MON 4621 at 0, 2.2, 3.3, and 4.4 kg/ha on growth and seedhead development of wild and cultivated proso millet (Panicum miliaceum L.) was determined. Application of mefluidide at 0.56 kg/ha 17 days after seeding reduced plant height and fresh shoot weight and inhibited panicle formation of both millets, whereas the 0.28 and 0.14 kg/ha rates had no effect on plant growth. When applied 23 days after seeding, mefluidide at 0.56 and 0.28 kg/ha reduced plant height of both millets and fresh shoot weight of wild proso millet. These rates also caused abnormal panicle formation. The 0.14 kg/ha rate had no effect on plant growth. All 3 rates of MON 4621, applied 16 days after seeding, reduced plant height and fresh shoot weight of both millets, and the 3.3 and 4.4 kg/ha rates were very effective in preventing panicle formation. Chemical names used: N-[2,4-dimethyl-5-[[(trifluoromethyl) sulfonyl]amino] phenyl]acetamide (mefluidide); (acetamide, N-[(acetylamino)methyl]-2-chloro-N-(2,6-diethylphenyl)(MON 4621).

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Awad-Allah, Mamdouh, Nehal Elekhtyar, Mohamed El-Abd, Mohamed Abdelkader, Mohamed Mahmoud, Azza Mohamed, Mohamed El-Diasty, Manal Said, Sahar Shamseldin et Mohamed Abdein. « Development of New Restorer Lines Carrying Some Restoring Fertility Genes with Flowering, Yield and Grains Quality Characteristics in Rice (Oryza sativa L.) ». Genes 13, n^o 3 (3 mars 2022) : 458. http://dx.doi.org/10.3390/genes13030458.

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This study was carried out using 22 promising restorer lines of rice and their parental lines to study genetic variability and genetic advance for yield and yield-associated grain quality traits and floral traits. These genotypes are evaluated in a replicated trial using Randomized Complete Block Design (RCBD) with three replications at the Experimental Farm of Sakha Agricultural Research Station, Sakha, Kafr El-Sheikh, Egypt, during the seasons from 2012 to 2020. Analysis of variance revealed that highly significant variations were observed among the genotypes for all the studied characters. Both GCV% and PCV% were high for the number of spikelets per panicle, the number of filled grains per panicle, and panicle weight. The genetic advance in the percentage of mean was high for days to plant height, panicle length, number of spikelets per panicle, number of filled grains per panicle, panicle weight, grain yield per plant, anther length, anther breadth, duration of floret opening, and head rice percentage. Mean performance of the rice genotypes indicated that the genotypes NRL 59, NRL 55, NRL 62, NRL 63, NRL 66, and NRL 54-2 were promising for grain yield and associated desirable traits. Thus, some of these promising lines can be promoted as a new rice variety and could be used as a source for developing new hybrid combinations in hybrid rice breeding programs. The percentage of advantage over better parent and Giza 178 as the commercial variety was significant and there were highly significant desirable values among the genotypes for all the studied traits in the two years, indicating that the selection is effective in the genetic improvements for these traits.

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Kusdiana, Alchemi Putri Juliantika, Joni Hidayat, Siti Zulaiha et Denih Wahyudin. « The Effect of Volume and Inoculation Method on the Development of Bacterial Panicle Blight Disease in Rice Plant ». Akta Agrosia 25, n^o 1 (30 juin 2022) : 17–23. http://dx.doi.org/10.31186/aa.25.1.17-23.

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Bacterial panicle blight in rice plants caused by Burkholderia glumae. These bacteria interfere with the grain filling process so that the grain is not filled and can cause yield losses of up to 75% on pathogenic infested land. This study was conducted to determine the effect of B. glumae suspension volume and inoculation method on the development of bacterial panicle blight. The research was conducted on vegetative and generative rice plants using a factorial completely randomized design with the volume of bacterial suspension as the first factor and the inoculation method as the second factor. The results showed that the higher the volume of the B. glumae suspension inoculated, the higher the severity of bacterial panicle blight in rice plants. Both the inoculation and injection methods can cause the same disease severity. Besides, the severity of bacterial panicle blight in the generative phase is more severe than in the vegetative phase.Keywords: Burkholderia glumae, generative phase, vegetative phase

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Zaman, Nadzariah Kamarul, Mohd Yusoff Abdullah, Sariam Othman et Nadzirah Kamarul Zaman. « Influence of water stress on phenological development, biomass production and yield of Malaysian aerobic and lowland rice ». DECEMBER 2019, n^o 13(12):2019 (20 décembre 2019) : 1927–35. http://dx.doi.org/10.21475/ajcs.19.13.12.p1384.

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This experiment was conducted to examine the comparative growth performance and yield of the first Malaysian aerobic rice variety, MARDI Aerob 1 (MA1) along with local lowland rice, MR 253 grown under water stress condition at selected growth stages. The experiment consisted of four treatments with three replications arranged in a randomized complete block design. The four treatments consisted of the control with no water stress throughout (T1), and water stress imposition at panicle initiation (T2), flowering (T3) and ripening (T4) stages. Water stress treatments were terminated when water deficit symptoms such as leaf rolling and wilting were detected. The effects of stress were assessed using parameters related to phenology, biomass and yield components. Results showed that both varieties were significantly affected, when water stress was imposed at the panicle initiation stage. At this stage, the water stress delayed the phenological development, reduced the panicle dry mass, and severely caused grain yield reduction for both varieties. The MR 253 variety had higher grain yield than MA1 under normal aerobic condition but not under water stress, while MA1 still was able to maintain reasonable high yield even under water stress condition, except when the water stress occurred at the panicle initiation stage. Panicle initiation stage was the most sensitive period for both varieties as water stress at this stage greatly affected the overall growth performance and grain yield for both varieties.

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Hozlár, Peter, Veronika Gregusová, Peter Nemeček, Svetlana Šliková et Michaela Havrlentová. « Study of Dynamic Accumulation in β-D-Glucan in Oat (Avena sativa L.) during Plant Development ». Polymers 14, n^o 13 (30 juin 2022) : 2668. http://dx.doi.org/10.3390/polym14132668.

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Oat is an important natural source of β-D-glucan. This polysaccharide of the cell wall of selected cereals is known for a number of health-promoting effects, such as reducing the level of cholesterol in the blood serum, stabilizing the level of blood glucose, or enhancing immunity. β-D-glucan has positive effects in the plant itself. There is a lack of information available, but the storage capacity of the polysaccharide and its importance as a protective substance in the plant during mild forms of biotic and abiotic stress are described. The accumulation of β-D-glucan during the ontogenetic development of oats (Avena sativa L.) was determined in the present work. Two naked (Valentin, Vaclav) and two hulled (Hronec, Tatran) oat varieties were used. Samples of each plant (root, stem, leaf, panicle) were collected in four stages of the plant’s development (BBCH 13, 30, 55, 71). The average content of the biopolymer was 0.29 ± 0.14% in roots, 0.32 ± 0.11% in stems, 0.48 ± 0.13% in leaves and 1.28 ± 0.79% in panicles, respectively. For root and panicle, in both hulled and naked oat varieties, sampling date was the factor of variability in the content of β-D-glucan. In stems in hulled varieties and leaves in naked varieties, neither the sampling date nor variety influenced the polysaccharide content. The content of β-D-glucan in the leaves of hulled and naked varieties decreased during the first three stages of plant development, but in the stage of milk ripeness the amount increased. The decreasing trend during milk ripeness, was also observed in the roots of both hulled and naked oats. However, in the panicle of hulled and naked oat varieties, the content of β-D-glucan increased during plant growth. Due to practical applications of natural resources of β-D-glucan and isolated β-D-glucan is useful to know the factors influencing its content as well as to ascertain the behavior of the polysaccharide during plant development.

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Dekhane, S. S., P. B. Jadhav, D. J. Patel et A. A. Bhoir. « Effect of application of “Grinophyll” on Growth and Yield of Rice ». International Journal of Horticulture, Agriculture and Food science 6, n^o 2 (2022) : 07–10. http://dx.doi.org/10.22161/ijhaf.6.2.2.

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The present investigation entitled “effect of application of “Grinophyll” on growth and yield of rice was carried out during kharif season of the year 2021 on the field of ASPEE, Agricultural Research and Development Foundation, Tansa farm, At-Nare, Tal-Wada, Dist- Palghar, Maharashtra. The experiment was laid out in Randomized Block Design. The three treatments (Control, Grinophyll @ 4ml, and Grinophyll @6ml per 15 liters of water) were replicated twice times on four varieties of rice namely Dandi, Gurjari, Jaya, and GAR-13. The plant population per meter square (34.5), plant height (105.9 cm), number of tillers per plant (13.7), number of panicles per plant (13), number of panicles per square meter (442) and length of panicle (25.8 cm) was recorded maximum with application of Grinophyll @ 6 ml /15 liters of water on rice cv. “GAR-13”. The highest number of seeds per panicle (203.5), test weight (34.1 g), grain yield (57.45 q/ha) and straw yield (85.08 q/ha) was found with application of Grinophyll @ 6 ml / 15 liters of water.The data clearly revealed that, the yield obtained with treatment Grinophyll @ 6 ml / 15 liters of water on rice cv. “GAR 13” was significantly higher than all other treatments and also for growth parameters.

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Li, Li, Fu Shi, Guoli Wang, Yanbin Guan, Yufan Zhang, Mingjie Chen, Junli Chang et al. « Conservation and Divergence of SQUAMOSA-PROMOTER BINDING PROTEIN-LIKE (SPL) Gene Family between Wheat and Rice ». International Journal of Molecular Sciences 23, n^o 4 (14 février 2022) : 2099. http://dx.doi.org/10.3390/ijms23042099.

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The SQUAMOSA-PROMOTER BINDING PROTEIN-LIKE (SPL) gene family affects plant architecture, panicle structure, and grain development, representing key genes for crop improvements. The objective of the present study is to utilize the well characterized SPLs’ functions in rice to facilitate the functional genomics of TaSPL genes. To achieve these goals, we combined several approaches, including genome-wide analysis of TaSPLs, comparative genomic analysis, expression profiling, and functional study of TaSPL3 in rice. We established the orthologous relationships of 56 TaSPL genes with the corresponding OsSPLs, laying a foundation for the comparison of known SPL functions between wheat and rice. Some TaSPLs exhibited different spatial–temporal expression patterns when compared to their rice orthologs, thus implicating functional divergence. TaSPL2/6/8/10 were identified to respond to different abiotic stresses through the combination of RNA-seq and qPCR expression analysis. Additionally, ectopic expression of TaSPL3 in rice promotes heading dates, affects leaf and stem development, and leads to smaller panicles and decreased yields per panicle. In conclusion, our work provides useful information toward cataloging of the functions of TaSPLs, emphasized the conservation and divergence between TaSPLs and OsSPLs, and identified the important SPL genes for wheat improvement.

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