Journal articles on the topic 'Doubled haploid (DH) population'
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1
Hu, Haixiao, Yujie Meng, Wenxin Liu, Shaojiang Chen, and Daniel E. Runcie. "Multi-Trait Genomic Prediction Improves Accuracy of Selection among Doubled Haploid Lines in Maize." International Journal of Molecular Sciences 23, no. 23 (November 22, 2022): 14558. http://dx.doi.org/10.3390/ijms232314558.
Full textAbstract:
Recent advances in maize doubled haploid (DH) technology have enabled the development of large numbers of DH lines quickly and efficiently. However, testing all possible hybrid crosses among DH lines is a challenge. Phenotyping haploid progenitors created during the DH process could accelerate the selection of DH lines. Based on phenotypic and genotypic data of a DH population and its corresponding haploids, we compared phenotypes and estimated genetic correlations between the two populations, compared genomic prediction accuracy of multi-trait models against conventional univariate models within the DH population, and evaluated whether incorporating phenotypic data from haploid lines into a multi-trait model could better predict performance of DH lines. We found significant phenotypic differences between DH and haploid lines for nearly all traits; however, their genetic correlations between populations were moderate to strong. Furthermore, a multi-trait model taking into account genetic correlations between traits in the single-environment trial or genetic covariances in multi-environment trials can significantly increase genomic prediction accuracy. However, integrating information of haploid lines did not further improve our prediction. Our findings highlight the superiority of multi-trait models in predicting performance of DH lines in maize breeding, but do not support the routine phenotyping and selection on haploid progenitors of DH lines.
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Friesen, H., and R. Scarth. "Utilization of doubled haploid technique in Brassica rapa population improvement." Canadian Journal of Plant Science 80, no. 1 (January 1, 2000): 75–82. http://dx.doi.org/10.4141/p99-041.
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The utilization of doubled haploid (DH) plants in population improvement of Brassica rapa was studied by randomly intercrossing 4, 8, 12 and 22 DH lines developed from the B. rapa cultivar Reward and the B. rapa breeding line DSC3 for two generations to constitute synthetic populations. The synthetic populations and the DH plants used in their formation were evaluated for agronomic performance at two locations in the field in 1996 and for genetic variation using random amplified polymorphic DNA (RAPD) analysis. Intercrossing as few as four DH lines from the breeding line DSC-3 produced a synthetic population with improved performance over that of the contributing DH lines. The synthetic population produced from the interpollination of eight DH lines showed an agronomic performance over that of the contributing DH lines to a level similar to the Reward donor population. RAPD analysis efficiently characterized the genotypic variation present in DH lines and synthetic populations, detecting 22–72% polymorphism between DH lines, 17–53% and 27–47% polymorphism in the first and second synthetic populations, respectively. This characterization may be useful as a tool in the reestablishment of heterogeneity and recovery of agronomic performance in B. rapa synthetic populations derived from DH lines by determining the level of genetic variability among DH lines and therefore optimal population size. Key words: Brassica rapa, synthetic population, doubled haploids, RAPD, agronomic performance
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Schön, C. C., P. M. Hayes, T. K. Blake, and S. J. Knapp. "Gametophytic selection in a winter × spring barley cross." Genome 34, no. 6 (December 1, 1991): 918–22. http://dx.doi.org/10.1139/g91-141.
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Segregation distortion and the consequences of gametophytic selection were assessed in a winter × spring barley cross by comparing segregation of enzyme, storage protein, DNA, and morphological markers in three populations derived from the same cross: a control F2 (F2C), a doubled-haploid (DH) population, and an F2 derived from F1 plants self-pollinated at 10 °C (F2T). Segregation distortion was present in the F2T and the doubled-haploid population. Based on a comparison of the F2C and the F2T, gametophytic selection as a consequence of self-pollination at 10 °C was operative on chromosome 7 in regions linked to Rrn2. Segregation distortion in favor of the winter parent was found in the doubled-haploid population. There were significant deviations from expected segregation ratios at two loci, but only at one of the loci was the gene number significantly different from the F2C. Despite segregation distortion, the doubled-haploid population should be suitable for linkage analyses, as estimates of recombination based on F2 and doubled-haploid data were in close agreement.Key words: Hordeum vulgare, segregation distortion, doubled haploids, gametophytic selection, cold tolerance.
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Patel, J. D., E. Reinbergs, and S. O. Fejer. "Recurrent selection in doubled-haploid populations of barley (Hordeurn vulgare L.)." Canadian Journal of Genetics and Cytology 27, no. 2 (April 1, 1985): 172–77. http://dx.doi.org/10.1139/g85-026.
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Cycle zero (C0) of recurrent selection in barley (Hordeum vulgare L.) was initiated by diallel mating of seven highly selected parents. A total of 398 doubled-haploid (C0DH) lines were derived from 21 crosses and were evaluated along with their parents in C0 experiment. Seven doubled-haploid lines (DH) were selected from the cycle zero (C0) experiment and intercrossed to form cycle 1 (C1). From the 21 crosses of the diallel, 260 doubled-haploid lines (C1DH) were derived and were evaluated along with the C0 and C1 parents. The frequency distribution of the standardized means of the DH lines from C0 and C1 indicated a slight response to selection for seed yield. Genetic analysis of the C1DH population showed high additive genetic variance for yield per hill, plant height, and yield per spike, and a high proportion of additive × additive epistasis for spikes per hill, days to heading, and 100-seed weight. Seven doubled-haploid lines were selected from different high-yielding crosses represented by C1DH lines. High selection pressure was applied for yield per hill, yield per spike, and spikes per hill. Further response to selection is expected in later cycles. The seven selected doubled-haploid lines will be used as the parents of the next recurrent selection cycle.Key words: recurrent selection, doubled haploids, additive, epistasis, heritability, Hordeum.
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Mikhailov, M. E. "Efficiency of the backcrossing method in dihaploid maize breeding." Plant Biotechnology and Breeding 2, no. 2 (August 29, 2019): 24–32. http://dx.doi.org/10.30901/2658-6266-2019-2-24-32.
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The doubled haploid (DH) lines, obtained by doubling the haploid genome, are now widely used in breeding many crops, since they allow to transfer gene variants to the homozygous state in a short time. However, the advantages of doubled haploids are not fully utilized in maize breeding. The present work is devoted to the evaluation of the backcrossing method efficiency and to further development of the original schemes of creating highly productive homozygous maize lines on the basis of DH lines originating from an interline F1 hybrid. Rf7 and Ku123 maize lines were used as the initial material. The breeding cycle consisted of producing haploid plants in the selected genotype (matroclinic haploidy using an inducer), subsequent chromosome doubling (colchicine‑induced or spontaneous), followed by multiplication of the doubled haploids for obtaining a new set of DH lines. In the first cycle, the DH lines were obtained from the F1 hybrid (Rf7 × Ku123), while in the subsequent cycles they were obtained from the genotypes obtained by crossing a DH line selected from the previous cycle with F1, P1 or P2. Three cycles of selection for productivity were performed, and in 2017 the DH lines obtained in all cycles were simultaneously tested in the field. The breeding progress was estimated by the increase in the first ear productivity compared to the best parent Rf7 (103.9 g per plant in 2017). The first selection cycle resulted in 43 DH lines obtained on the basis of the F1 hybrid. Productivity of the best line rk‑5 amounted to 112.5 g per plant. Three lines (rk‑6, rk‑5 and rk‑22) selected for the next cycle were further crossed with F1 or with the parental line Rf7. The second selection cycle yielded three series containing 41, 49 and 16 lines, while productivity of the best genotypes was 121.2, 117.0 и 107.1 g per plant, respectively. The third cycle included populations of 24 and 8 lines obtained through backcrosses with Rf7 and Ku123 lines, respectively. The best genotypes in these series had productivity of 135.6 and 97.7 g per plant. As a result of selection, the obtained rk‑433 line had a productivity 30.5% higher than that of the best parent Rf7. The progress averaged 10.2% per cycle. In maize breeding using doubled haploids it is promising to use backcrosses of the selected DH lines with the initial material or with F1. Thanks to such an approach, a noticeable progress can be reached with a small number of cycles including from 20 to 50 DH lines.
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Dewan, D. B., G. Rakow, and R. K. Downey. "Growth and yield of doubled haploid lines of oilseed Brassica rapa." Canadian Journal of Plant Science 78, no. 4 (October 1, 1998): 537–44. http://dx.doi.org/10.4141/p97-104.
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The production of doubled haploid (DH) lines of Brassica rapa could be an efficient procedure for the development of inbred parents for hybrid production. A total of 162 B. rapa DH lines were evaluated in field tests at Saskatoon, Canada, in single row, replicated tests and 10 DH lines were tested in four-row plot, multilocation, replicated tests. Seed of DH lines was produced by bud selfing in the greenhouse. Approximately one-fifth of all DH lines tested were chlorophyll deficient, presumably due to the expression of recessive alleles. Inbreeding depression was evident in low seed and biological yields, low number of seeds per pod and delayed flowering. Seed yield of DH lines was positively associated with the number of seeds per pod, early flowering and a long pod-filling period. One DH line was equal in yield to its donor population (DP), suggesting that dominance deviation was the genetic basis for high seed yield in this species. The consistent performance of DH lines over years and locations indicated that DH lines may be selected after 1 year of evaluation for combining ability testing. Higher yielding DH lines of B. rapa must be selected before they can be used as parents for hybrid development. Key words: Brassica rapa, doubled haploid, field evaluation
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Meena, Rakesh Kumar. "A Review on Haploid and Double Haploids in Ornamental Plants." Current Research in Agriculture and Farming 2, no. 3 (June 30, 2021): 1–7. http://dx.doi.org/10.18782/2582-7146.138.
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Sporophyte plants with many gametophytic chromosomes are called haploid plants. These plants can be produced naturally or through in vitro or in vivo induction techniques. Double haploid (DH) can be obtained by doubling the number of haploid chromosomes spontaneously or artificially. They are homozygous, and this homozygosity will be realized in the life cycle of a generation using the DH production system. This production system is used to correct heterosis. Easy to interact with the DH population. DH can be used as parental inbreds of new varieties or self-pollinated plants or cross-pollinated plants. Haploids can be used to isolate mutants, especially if the mutant allele is not diploid. If the haploid is transformed immediately after the chromosome is copied, the plant can be obtained step by step. By combining biotechnological means with conventional methods, the important goal of improving cultivated plants can be achieved in a short time. This article analyzes the various developments in the field of haploid species related to economically important ornamental species.
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GUPTA, MAMTA, MUKESH CHOUDHARY, HARISH KUMAR, VINEET KASWAN, YASHMEET KAUR, JEET RAM CHOUDHARY, and SURESH YADAV. "Doubled Haploid Technology in Maize (Zea mays): Status and Applications." Indian Journal of Agricultural Sciences 92, no. 3 (March 29, 2022): 283–91. http://dx.doi.org/10.56093/ijas.v92i3.122539.
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Maize (Zea mays L.) is the third most important staple crop after rice and wheat with enormous diversity and adaptation ability. Hybrid breeding is the most important approach for developing high yielding cultivars in maize. It relies upon the generation of pure inbred lines with desirable traits in quick span to achieve higher genetic gains. Rapidly rising global population and climate change necessitates the development of innovative technologies that can help to safeguard the food security in future. Doubled Haploid (DH) technology is the best approach for rapid development of new inbred lines and has contributed immensely in the rapid generation of inbred lines and hybrid development. In addition, the use of molecular markers with DH technology resulted into mapping of genomic regions for different traits. The recent development in identification of alternative markers for haploid selection and genome editing approaches will further strengthen the DH technology for commercial maize breeding. This review describes important landmarks of maize DH technology, its applications, and recent advances in utilization of emerging technologies, viz. CRIPSR-cas and genomics approaches for DH technology
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Bentolila, S., T. Hardy, C. Guitton, and G. Freyssinet. "Comparative genetic analyses of F2 plants and anther culture derived plants of maize." Genome 35, no. 4 (August 1, 1992): 575–82. http://dx.doi.org/10.1139/g92-086.
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The doubled haploid (DH) lines represent a potentially powerful tool in maize genetics and breeding. The goal of this work was to test the ability of the DH lines to be used in these research areas. This was achieved by comparing the segregation and recombination of 94 restriction fragment length polymorphism (RFLP) markers in an F2 population and an anther culture (AC) derived population of maize (Zea mays L.). These were obtained from the cross of R6 (an elite maize line of Mo17/Oh43 group, not responsive to anther culture) with DH89.1 (a maize line very responsive to anther culture provided by Dr. M. Beckert). Despite the single factor disturbed segregations and the impossibility to discriminate between the loose and numerous spurious linkages detected with DH data, a linkage map could be constructed. The comparison of the DH linkage map with the F2 linkage map demonstrated two points. First, the markers order is conserved between the two maps. Second and most importantly, 97% of the length covered by the DH map proved to be consistent with the F2 map. These results are discussed in relation to the use of DH lines in maize breeding and gene mapping.Key words: corn, doubled haploid lines, restriction fragment length polymorphism markers, disturbed segregation, mapping.
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Navabi, Z. K., I. A. P. Parkin, J. C. Pires, Z. Xiong, M. R. Thiagarajah, A. G. Good, and M. H. Rahman. "Introgression of B-genome chromosomes in a doubled haploid population of Brassica napus × B. carinata." Genome 53, no. 8 (August 2010): 619–29. http://dx.doi.org/10.1139/g10-039.
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The Brassica B-genome species possess many valuable agronomic and disease resistance traits. To transfer traits from the B genome of B. carinata into B. napus , an interspecific cross between B. napus and B. carinata was performed and a doubled haploid (DH) population was generated from the BC2S3 generation. Successful production of interspecific DH lines as identified using B-genome microsatellite markers is reported. Five percent of DH lines carry either intact B-genome chromosomes or chromosomes that have deletions. All of the DH lines have linkage group J13/B7 in common. This was further confirmed using B. nigra genomic DNA in a fluorescent in situ hybridization assay where the B-genome chromosomes were visualized and distinguished from the A- and C-genome chromosomes. The 60 DH lines were also evaluated for morphological traits in the field for two seasons and were tested for resistance to blackleg, caused by Leptosphaeria maculans , under greenhouse conditions. Variation in the DH population followed a normal distribution for several agronomic traits and response to blackleg. The lines with B-genome chromosomes were significantly different (p < 0.01) from the lines without B-genome chromosomes for both morphological and seed quality traits such as days to flowering, days to maturity, and erucic acid content.
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Showkath Babu, Budensab Mamtazbi, Hirenallur Chandappa Lohithaswa, Gangadharaswamy Triveni, Mallana Gowdra Mallikarjuna, Nanjundappa Mallikarjuna, Devanagondi C. Balasundara, and Pandravada Anand. "Comparative Assessment of Genetic Variability Realised in Doubled Haploids Induced from F1 and F2 Plants for Response to Fusarium Stalk Rot and Yield Traits in Maize (Zea mays L.)." Agronomy 13, no. 1 (December 28, 2022): 100. http://dx.doi.org/10.3390/agronomy13010100.
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Doubled-haploid lines (DHs) are normally produced from F1 plants in maize (Zea mays L.). Several studies have found a low frequency of recombinants in doubled haploids produced from F1 plants that could limit the selection response. Hence, an attempt was made to produce doubled haploids from the F2 generation to verify whether one more round of meiotic recombination could lead to increased genetic variability and assess the response to selection. The F1 and F2 plants of two cross-combinations, VL1043 × CM212 and VL121096 × CM202, were subjected to doubled-haploid production and evaluated in terms of their reaction to Fusarium stalk rot and yield traits along with F2 individuals of the same two crosses. There was significant variation in the number of DHs produced when F1 and F2 plants were subjected to DH production in the cross VL121096 × CM202. Furthermore, substantial genetic variability was observed among the DHs produced from the F1 generation (DHF1s), F2 generation (DHF2s), and F2s for Fusarium stalk rot (FSR) resistance. The genetic variance was more extensive in DHF2 compared to DHF1 plants in the cross VL1043 × CM212. Extreme candidate plants (highly resistant, resistant, and highly susceptible) were found in the F2 generation with a more standardized range than in the DHs. In the DH populations, the close correspondence between the phenotypic coefficient of variability (PCV) and the genotypic coefficient of variability (GCV) indicated less influence from the environment compared to the F2 plants. The heritability estimates in the DHs were greater than in the F2 plants of the VL1043 × CM212 cross, while in the VL121096 × CM202 cross, the heritability was almost the same between the DHs and F2 plants due to the relatively small population size of the DHs. The positively skewed leptokurtic distribution of the DH populations indicated the role of fewer genes, with the majority of them exhibiting complementary epistasis with decreasing effects in response to FSR. The mean estimated yield and genotypic variance in the top crosses produced from randomly chosen DHF1 and DHF2 plants of the cross VL1043 × CM212 were similar in magnitude.
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Wang, Jian, Yuexuan Cao, Kejian Wang, and Chaolei Liu. "Development of Multiple-Heading-Date mtl Haploid Inducer Lines in Rice." Agriculture 12, no. 6 (June 2, 2022): 806. http://dx.doi.org/10.3390/agriculture12060806.
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In vivo doubled haploid (DH) production based on crossing heterozygous germplasm with mtl haploid inducer lines promises to transform modern rice (Oryza sativa) breeding. However, this technology is limited, as haploid inducers and pollen acceptors have asynchronous heading dates. To address this obstacle, we developed a panel of multiple-heading-date mtl haploid inducer lines that produce pollen for more than 35 days. We edited the MTL gene in a hybrid rice with the CRISPR-Cas9 system. We then selected transgene-free homozygous mutants in the T1 generation and reproduced to T4 generation by single-seed descent method. We obtained 547 mtl haploid inducers with diverse heading dates (from 73 to 110 days) and selected 16 lines comprising a core population with continuous flowering. The seed-setting rate and haploid induction rate (HIR) of the core panel were 4.0–12.7% and 2.8–12.0%, respectively. Thus, our strategy of using multiple-heading-date mtl haploid inducers could accelerate the use of in vivo DH technology in rice breeding.
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Jiao, Yanyan, Jinlong Li, Wei Li, Ming Chen, Mengran Li, Wenxin Liu, Chenxu Liu, and Shaojiang Chen. "QTL Mapping and Prediction of Haploid Male Fertility Traits in Maize (Zea mays L.)." Plants 9, no. 7 (July 3, 2020): 836. http://dx.doi.org/10.3390/plants9070836.
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Chromosome doubling of maize haploids is a bottleneck in the large-scale application of doubled haploid (DH) technology. Spontaneous chromosome doubling (SCD) of haploid has been taken as an important method in the production of DH lines and low haploid male fertility (HMF) is a main limiting factor for the use of SCD. To study its genetic basis, haploids of 119 DH lines derived from a cross between inbred lines Qi319 and Chang7-2 were used to map the quantitative trait locus (QTL) contributing to HMF. Three traits including anther emergence rate (AER), anther emergence score (AES) and pollen production score (PPS) of the haploid population were evaluated at two locations. The heritability of the three traits ranged from 0.70 to 0.81. The QTL contributing to AER, AES and PPS were identified on the chromosomes 1, 2, 3, 4, 5, 7, 9 and 10. Five major QTL, qAER5-1, qAER5-2, qAES3, qPPS1 and qPPS5, were found and each could explain more than 15% of the phenotypic variance at least in one environment. Two major QTL, qPPS1 and qPPS5, and two minor QTL, qAES2 and qAER3, were repeatedly detected at both locations. To increase the application efficiency of HMF in breeding programs, genomic prediction for the three traits were carried out with ridge regression best linear unbiased prediction (rrBLUP) and rrBLUP adding QTL effects (rrBLUP-QTL). The prediction accuracies of rrBLUP-QTL were significantly higher than that by rrBLUP for three traits (p < 0.001), which indirectly indicates these QTL were effective. The prediction accuracies for PPS were 0.604 (rrBLUP) and 0.703 (rrBLUP-QTL) across both locations, which were higher than that of AER and AES. Overall, this study provides important information to understand the genetic architecture of SCD of maize haploids.
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Hölker, Armin C., Manfred Mayer, Thomas Presterl, Therese Bolduan, Eva Bauer, Bernardo Ordas, Pedro C. Brauner, Milena Ouzunova, Albrecht E. Melchinger, and Chris-Carolin Schön. "European maize landraces made accessible for plant breeding and genome-based studies." Theoretical and Applied Genetics 132, no. 12 (September 26, 2019): 3333–45. http://dx.doi.org/10.1007/s00122-019-03428-8.
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Key message Doubled-haploid libraries from landraces capture native genetic diversity for a multitude of quantitative traits and make it accessible for breeding and genome-based studies. Abstract Maize landraces comprise large allelic diversity. We created doubled-haploid (DH) libraries from three European flint maize landraces and characterized them with respect to their molecular diversity, population structure, trait means, variances, and trait correlations. In total, 899 DH lines were evaluated using high-quality genotypic and multi-environment phenotypic data from up to 11 environments. The DH lines covered 95% of the molecular variation present in 35 landraces of an earlier study and represent the original three landrace populations in an unbiased manner. A comprehensive analysis of the target trait plant development at early growth stages as well as other important agronomic traits revealed large genetic variation for line per se and testcross performance. The majority of the 378 DH lines evaluated as testcrosses outperformed the commercial hybrids for early development. For total biomass yield, we observed a yield gap of 15% between mean testcross yield of the commercial hybrids and mean testcross yield of the DH lines. The DH lines also exhibited genetic variation for undesirable traits like root lodging and tillering, but correlations with target traits early development and yield were low or nonsignificant. The presented diversity atlas is a valuable, publicly available resource for genome-based studies to identify novel trait variation and evaluate the prospects of genomic prediction in landrace-derived material.
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Rádi, F., K. Török, M. Nagymihály, A. Kereszt, and D. Dudits. "Improved reliability in production of maize inbred lines by the combination of the R1-navajo marker with flow cytometry or microsatellite genotyping." Cereal Research Communications 48, no. 4 (June 23, 2020): 423–30. http://dx.doi.org/10.1007/s42976-020-00054-9.
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AbstractDoubled haploid (DH) technology is an essential component in producing inbred lines for a competitive maize (Zea mays L.) breeding program. The R1-navajo (R1-nj) gene provides phenotypic marker that insures only variable reliability for seed selection of haploid embryos. Therefore, in the present study we outline a complex protocol for early stage genome size determination that integrates the phenotypic screening with the flow cytometry of nuclei from root tips and with the use of DNA isolated from seedlings for molecular marker-based genotyping. In a representative experiment with three genotypes, only 59% of the color marker pre-selected seeds were confirmed to be haploid by cytometric analysis of nuclei isolated from root tips. As a novel tool we have identified the UMC1152 SSR marker being polymorphic between the haploid inducer line (K405) and the K4390 hybrid as parents to screen seedlings pre-selected with the R1-navajo marker. Using this molecular marker, alleles characteristic for the inducer K405 line could not be detected in 83% of seedlings previously selected as haploid candidate. Seedlings identified as haploids were exposed to 0.06% colchicine solution for rediploidization. This procedure resulted in doubled haploids with 3% frequency relative to the initial population as it was quantified by the number of mature maize plants with fertile tassel. The described complex approach can support safer identification of haploids at early seedling stage in a hybrid population derived from crossing with a haploid inducer line.
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Tanhuanpää, Pirjo, Outi Manninen, and Elina Kiviharju. "QTLs for important breeding characteristics in the doubled haploid oat progeny." Genome 53, no. 6 (June 2010): 482–93. http://dx.doi.org/10.1139/g10-022.
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A homozygous mapping population, consisting of doubled haploid (DH) oat ( Avena sativa L.) plants generated through anther culture of F1 plants from the cross between the Finnish cultivar ‘Aslak’ and the Swedish cultivar ‘Matilda’, was used to construct an oat linkage map. Ten agronomic and quality traits were analyzed in the DH plants from field trials in 2005 and 2006. Leaf blotch (caused by Pyrenophora avenae ) resistance was also evaluated in a greenhouse test with 2 different isolates. One to 8 quantitative trait loci (QTLs) were found to be associated with each trait studied. Some chromosomal regions affected more than 1 trait; for example, 4 regions affected both protein and oil content. This study gives valuable information to oat breeders concerning the inheritance of important traits, and it provides potential tools to assist breeding.
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Lionneton, E., S. Ravera, L. Sanchez, G. Aubert, R. Delourme, and S. Ochatt. "Development of an AFLP-based linkage map and localization of QTLs for seed fatty acid content in condiment mustard (Brassica juncea)." Genome 45, no. 6 (December 1, 2002): 1203–15. http://dx.doi.org/10.1139/g02-095.
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A genetic linkage map of Brassica juncea based on AFLP and RAPD markers was constructed using 131 F1-derived doubled-haploid (DH) plants from a cross between two mustard lines. The map included 273 markers (264 AFLP, 9 RAPD) arranged on 18 linkage groups, and covered a total genetic distance of 1641 cM; 18.3% of the AFLP markers showed a segregation distortion (P < 0.01). The markers with biased segregation were clustered on seven linkage groups. QTLs for oil contents, palmitic acid (16:0), stearic acid (18:0), oleic acid (18:1), linoleic acid (18:2), linolenic acid (18:3), eicosenoic acid (20:1), and erucic acid (22:1), were mapped on the AFLP linkage map. Correlation studies among fatty acids in the DH population and the localization of QTLs involved in their control indicated that a major gene located on linkage group (LG) 2 controlled the elongation step of erucic acid.Key words: Brassica juncea, doubled haploid, AFLP genetic linkage map, fatty acids, QTL.
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Zeitler, Leo, Jeffrey Ross-Ibarra, and Markus G. Stetter. "Selective Loss of Diversity in Doubled-Haploid Lines from European Maize Landraces." G3: Genes|Genomes|Genetics 10, no. 7 (May 28, 2020): 2497–506. http://dx.doi.org/10.1534/g3.120.401196.
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Maize landraces are well adapted to their local environments and present valuable sources of genetic diversity for breeding and conservation. But the maintenance of open-pollinated landraces in ex-situ programs is challenging, as regeneration of seed can often lead to inbreeding depression and the loss of diversity due to genetic drift. Recent reports suggest that the production of doubled-haploid (DH) lines from landraces may serve as a convenient means to preserve genetic diversity in a homozygous form that is immediately useful for modern breeding. The production of doubled-haploid (DH) lines presents an extreme case of inbreeding which results in instantaneous homozygosity genome-wide. Here, we analyzed the effect of DH production on genetic diversity, using genome-wide SNP data from hundreds of individuals of five European landraces and their related DH lines. In contrast to previous findings, we observe a dramatic loss of diversity at both the haplotype level and that of individual SNPs. We identify thousands of SNPs that exhibit allele frequency differences larger than expected under models of neutral genetic drift and document losses of shared haplotypes. We find evidence consistent with selection at functional sites that are potentially involved in the diversity differences between landrace and DH populations. Although we were unable to uncover more details about the mode of selection, we conclude that landrace DH lines may be a valuable tool for the introduction of variation into maize breeding programs but come at the cost of decreased genetic diversity.
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Molnar, S. J., L. E. James, and K. J. Kasha. "Inheritance and RAPD tagging of multiple genes for resistance to net blotch in barley." Genome 43, no. 2 (March 15, 2000): 224–31. http://dx.doi.org/10.1139/g99-111.
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A doubled haploid barley (Hordeum vulgare L.) population that was created from a cross between cultivars 'Léger' and 'CI 9831' was characterized by RAPD (random amplified polymorphic DNA) markers for resistance to isolate WRS857 of Pyrenophora teres Drechs. f. sp. maculata Smedeg., the causal agent of the spot form of net blotch. Resistance, which initially appeared to be conferred by a single gene from the approximate 1:1 (resistant : susceptible) segregation ratio of the doubled-haploid (DH) progeny, was found to be associated with three different genomic regions by RAPD analysis. Of 500 RAPD random primers that were screened against the parents, 195 revealed polymorphic bands, seven showed an association to the resistance in bulks, and these seven markers were mapped to three unlinked genomic regions. Two of these regions, one of which was mapped to chromosome 2, have major resistance genes. The third region has some homology to the chromosome 2 region. This study demonstrates the simultaneous location of markers for more than one gene governing a trait by using RAPD and bulked segregant analysis (BSA). Key words: net blotch, RAPD markers, bulked segregant analysis, barley, doubled haploids.
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Hu, Tianci, and Ken J. Kasha. "Performance of isolated microspore-derived doubled haploids of wheat (Triticum aestivum L.)." Canadian Journal of Plant Science 77, no. 4 (October 1, 1997): 549–54. http://dx.doi.org/10.4141/p96-155.
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Ploidy level, genetic stability and field performance of isolated microspore-derived wheat plants were evaluated. The ploidy levels of isolated microspore-derived wheat plants from cv. Chris and reciprocal crosses of Chris × Sinton were determined by two methods, namely chromosome counts of root tip cells and flow cytometric measurement of nuclear DNA content from leaves. Both methods gave similar results with the frequencies of spontaneous chromosome doubling and completely fertile plants among microspore-derived H0 plants of wheat being about 80% and 75%, respectively, based on two H0 populations. Only 1.7% were aneuploid and 16% were haploid. Spontaneous mutation frequencies were low with 1 of 124 Chris DH plants having a recessive mutant for lemma awns while three were grass-like plants in the H0 generation. The field-measured traits of microspore-derived DH lines were similar to the check by the third generation. Ninety-two percent and 70% of Chris DH lines had 1000-kernel weights and yields similar to the check, respectively. These results indicate that microspore-derived DH lines should have good potential for applications in plant breeding, in vitro selection, plant transformation and genetic studies. Key words: Wheat, microspore, culture, haploidy, performance, stability
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Mowers, Ronald P., and David J. Foster. "Genetic Variance Estimates for Maize Yield, Grain Moisture, and Stalk Lodging for Doubled-Haploid and Conventional Selfed-Line Hybrids." Plants 9, no. 2 (January 22, 2020): 138. http://dx.doi.org/10.3390/plants9020138.
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An experiment was conducted to compare estimated genetic variance for maize doubled haploid (DH) with conventional twice-selfed (S2)-line hybrids. Starting with a 4-parent population, at least 160 lines were derived using both of these methods and crossed with two inbred testers. For both inbred testers, maize hybrid grain yield and stalk lodging had higher estimated genetic variances for DH than for S2. For one of the testers, estimated grain moisture genetic variance was higher for DH, but not for the other. The DH hybrid yield distributions on both testers were flatter and had more entries in tails compared with S2 distributions. With complete homozygosity of DH lines and the subsequent increased genetic variance among lines, the expected response to yield selection is higher for DH than for S2 line hybrids.
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Tan, M. K., A. P. Verbyla, B. R. Cullis, P. Martin, A. W. Milgate, and J. R. Oliver. "Genetics of late maturity α-amylase in a doubled haploid wheat population." Crop and Pasture Science 61, no. 2 (2010): 153. http://dx.doi.org/10.1071/cp09239.
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Late maturity α-amylase (LMA) in wheat is a defect where high-isoelectric point (pI) α-amylase accumulates in the ripening grain. Wheat genotypes vary in expression from zero to high levels of α-amylase, the latter with detrimental consequences on their use for value-added end products. Expression in each genotype is characterised by varying numbers of grains affected and different levels in each grain. Analysis of a doubled haploid (DH) population (188 lines) from WW1842 × Whistler has identified significant QTL on chromosomes 2DL, 3A, 3B, 3D, 4B, 4D, 5DS and 5BL. The 4B LMA allele (P < 0.0001) from Whistler is closely linked to the QTL for the ‘tall’ allele (P < 0.0001) of the Rht-B1 gene. The 4D LMA QTL (P < 0.0001) in WW1842 co-locates with the QTL for the ‘tall’ allele (P < 0.0001) of the Rht-D1 gene. This study has shown for the first time that a DH cross between two semi-dwarf cultivars with low or no LMA produces ~25% of progeny lines of the ‘tall’ genotypes with a high frequency of LMA. This is attributed to the large additive positive effects from the combination of one recessive ‘tall’ Rht-B1 gene and one recessive ‘tall’ Rht-D1 gene. High-yielding semi-dwarf genotypes with different combinations of Rht-B1 and Rht-D1 alleles which have very low or non-existent LMA expression (e.g. WW1842 and Whistler) may meet industry criteria for registration as commercial wheat varieties. However, when they are used as breeding lines, the cross produces some progeny genotypes with severe levels of LMA. These LMA genotypes comprise the gibberellic acid-sensitive ‘tall’ progenies and a very small proportion of semi-dwarfs. Thus, it is of paramount importance to screen the defect in wheat breeding programs. The suite of QTL identified for LMA will enable the use of marker assisted selection in the pyramiding of the beneficial QTL to maximise yield and minimise (or eliminate) LMA in semi-dwarf genotypes.
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Walker, Ryan, Leonard Pike, Monica Menz, Kil Sun Yoo, and Sung Gil Kim. "(254) Molecular Characterization of Doubled Haploid and Conventional Onion Lines using AFLPs and SSRs." HortScience 40, no. 4 (July 2005): 1088D—1088. http://dx.doi.org/10.21273/hortsci.40.4.1088d.
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Onions suffer from severe inbreeding depression, which has prevented the creation of homozygous inbreds in breeding programs. The creation of doubled haploid (DH) lines in onion is an anomaly, and provides a unique opportunity to study both how these lines would perform in a breeding program and why they do not exhibit more inbreeding depression. Seven DH lines were developed at Texas A&M University from five different short-day F1 and F2 populations. Five equivalent conventional inbred lines, breeding lines developed from the same parents as the DH lines, have been identified from the onion-breeding program. The DH lines, the conventional inbred lines, and their parents have been analyzed using SSR and AFLP markers. SSR markers yielded a polymorphism rate of 55% vs. 3% with the AFLPs. Analysis has shown remnant heterozygosity both in the parental lines and in the conventional inbreds and has confirmed the uniformity of the DH lines. Genetic similarity estimates have been calculated using the molecular data to determine the suitability of comparing the yield heterosis of crosses between the conventional lines and the DH lines in a diallele analysis.
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Deynze, A. E. Van, B. S. Landry, and K. P. Pauls. "The identification of restriction fragment length polymorphisms linked to seed colour genes in Brassica napus." Genome 38, no. 3 (June 1, 1995): 534–42. http://dx.doi.org/10.1139/g95-069.
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Restriction fragment length polymorphisms (RFLPs) linked to genes controlling seed colour were identified in rapeseed (Brassica napus). The efficiency of the RFLP analysis was enhanced by utilizing bulked segregant analysis, DNA clones that had previously been used to construct a RFLP map of B. napus, and a doubled-haploid (DH) population segregating for seed colour. Markers for two of the three seed colour genes segregating in the DH population were identified on the basis of χ2 analyses of marker distributions among visually classified black-, brown-, and yellow-seeded DH lines as well as ANOVA and quantitative trait locus analysis of light-reflectance measurements from seeds of the DH lines. The RFLP markers linked to seed colour that were identified in the present study will allow breeding strategies based on genotype selection to be developed for seed colour in rapeseed.Key words: RFLP markers, seed colour genes, rapeseed.
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Raman, Rosy, Simon Diffey, Jason Carling, Ray B. Cowley, Andrzej Kilian, David J. Luckett, and Harsh Raman. "Quantitative genetic analysis of grain yield in an Australian Brassica napus doubled-haploid population." Crop and Pasture Science 67, no. 4 (2016): 298. http://dx.doi.org/10.1071/cp15283.
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High yield is a major objective in canola-breeding programs. We analysed the genetic determinants controlling variation in grain yield in a doubled-haploid (DH) breeding population derived from a single BC1F1 plant from the cross Skipton/Ag-Spectrum//Skipton (designated as the SAgS population). DH lines were evaluated for flowering time and yield in two replicated trials and exhibited significant genetic variation for both traits. Yield showed negative correlation with flowering time; lines that flowered earlier had higher yield than late-flowering lines. A genetic linkage map comprising 7716 DArTseq markers was constructed for the SAgS population, and a ‘bin’ map based on 508 discrete single-position (non-co-segregating) marker loci was used for quantitative trait locus (QTL) analysis. We identified 20 QTLs (LOD ≥2) associated with variation in flowering time and grain yield. Two QTLs (Qy.wwai-A7/Qdtf.wwai-A7/Qfs.wwai-A7 and Qy.wwai-C3a/Qfs.wwai-C3a) appeared repeatedly across experiments, accounting for 4.9–19% of the genotypic variation in flowering time and yield and were located on chromosomes A07 and C03. We identified 22 putative candidate genes for flowering time as well as grain yield, and all were located in a range of 935 bp to 2.97 Mb from markers underlying QTLs. This research provides useful information to be used for breeding high-yielding canola varieties by combining favourable alleles for early flowering and higher grain yield at loci on chromosomes A07, C03 and possibly on A06.
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Tripathy, S. K. "High throughput anther culture response in an upland rice cross ‘Khandagiri x Dular’." Journal of Environmental Biology 43, no. 03 (May 2, 2022): 420–29. http://dx.doi.org/10.22438/jeb/43/3/mrn-2020.
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Aim: The experiment was conducted to maximize anther culture response in an upland indica rice cross amenable for drought tolerance breeding. Methodology: The cold pre-treated anthers of a cross Khandagiri (drought sensitive) x Dular (drought tolerant) were cultured on N6, SK3, MS and CIM media at varying concentration of hormones (2,4-D, Kn and NAA) to assess callusing response. Embryogenic calli were placed on regeneration medium (RM) with varying concentration of Kn, BAP and NAA for plant regeneration. The plantlets were acclimatized in half-strength MS basal liquid medium for one week before transferring to pot mixture (peat moss: perlite 2:1, v/v) for plant establishment in glasshouse under partial shade. Finally, the plantlets were checked for doubled haploid status by cytological study of root tips. Results: Anther culture response was found to be media and genotype-specific. F1-progenies responded better than either of the parents. A modified MS callus induction medium (CIM) with 1.5mg/l 2,4-D + 0.5mg/l Kn resulted impressively higher callusing response (30.2%) with nodular calli than SK3>MS>N6. High frequency (12.8%) of albino-free green plant regeneration with well developed rooting was achieved in RM medium (a modified MS) containing 2mg/l BAP and 0.5mg/l NAA. A total 129 doubled haploid (DH) plants (each with 12 pairs of chromosomes) were recovered which maintained normal growth, set seeds and resulted in true breeding DH lines. Interpretation: The high throughput regeneration system is amenable for doubled haploid production from indica crosses. Besides, the present doubled haploid stock can serve as an ideal mapping population and as such targeted for marker aided selection for early development of drought tolerant rice varieties.
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Balla, Krisztina, Ildikó Karsai, Tibor Kiss, Szilvia Bencze, Zoltán Bedő, and Ottó Veisz. "Productivity of a doubled haploid winter wheat population under heat stress." Open Life Sciences 7, no. 6 (December 1, 2012): 1084–91. http://dx.doi.org/10.2478/s11535-012-0097-1.
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AbstractBreeding of new winter wheat cultivars with good heat tolerance requires better understanding of the genetic background of heat tolerance. In the present work the effect of heat stress on the 6th day after heading was investigated in a doubled haploid (DH) population arising from a cross between heat-sensitive (Plainsman V) and heat-tolerant (Mv Magma) cultivars. Averaged over the population, heat stress was found to result in a significant reduction in biomass, grain yield and grain number per plant, and in thousand-kernel weight (TKW) and harvest index. High temperature had the greatest effect on the grain yield, with a drop of 36.2% compared with the control. This could be attributed jointly to significant reductions in the TKW of the main ear and in the grain number of the side tillers. The relationship between the yield parameters was confirmed by the positive correlations obtained for the lines in the population. The diverse levels of heat tolerance in the different lines were confirmed by the significant differences in the reduction in the chlorophyll content (SPAD index) of the flag-leaves and in yield parameters. The changes in yield components in stress condition, however, can be still the most effective tools for heat stress evaluation.
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Hasan, Muhammad Jakir, and Habibur Rahman. "Genetics and molecular mapping of resistance to Plasmodiophora brassicae pathotypes 2, 3, 5, 6, and 8 in rutabaga (Brassica napus var. napobrassica)." Genome 59, no. 10 (October 2016): 805–15. http://dx.doi.org/10.1139/gen-2016-0034.
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Clubroot disease, caused by Plasmodiophora brassicae, is a threat to the production of Brassica crops including oilseed B. napus. In Canada, several pathotypes of this pathogen, such as pathotypes 2, 3, 5, 6, and 8, were identified, and resistance to these pathotypes was found in a rutabaga (B. napus var. napobrassica) genotype. In this paper, we report the genetic basis and molecular mapping of this resistance by use of F2, backcross (BC1), and doubled haploid (DH) populations generated from crossing of this rutabaga line to a susceptible spring B. napus canola line. The F1, F2, and BC1 populations were evaluated for resistance to pathotype 3, and the DH population was evaluated for resistance to pathotypes 2, 3, 5, 6, and 8. A 3:1 segregation in F2 and a 1:1 segregation in BC1 were found for resistance to pathotype 3, and a 1:1 segregation was found in the DH population for resistance to all pathotypes. Molecular mapping by using the DH population identified a genomic region on chromosome A8 carrying resistance to all five pathotypes. This suggests that a single gene or a cluster of genes, located in this genomic region, is involved in the control of resistance to these pathotypes.
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Kota, Raja, Markus Wolf, Wolfgang Michalek, and Andreas Graner. "Application of denaturing high-performance liquid chromatography for mapping of single nucleotide polymorphisms in barley (Hordeum vulgare L.)." Genome 44, no. 4 (August 1, 2001): 523–28. http://dx.doi.org/10.1139/g01-053.
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Recent advances in DNA sequence analysis and the establishment of high-throughput assays have provided the framework for large-scale discovery and analysis of DNA sequence variation. In this context, single nucleotide polymorphisms (SNPs) are of particular interest. To initiate a systematic approach to develop an SNP map of barley (Hordeum vulgare L.), we have employed denaturing high-performance liquid chromatography (DHPLC) to analyse segregating SNP patterns in a doubled-haploid (DH) mapping population. To this end, SNPs between the parental genotypes were identified using a direct sequencing approach. Once a SNP was established between the parents, the optimal melting temperature of the PCR fragment containing the SNP was predicted for its analysis by DHPLC. Following the detection of the optimal temperature, the DH lines were analysed for the presence of either of the alleles. To test the utility of the analysis, data from previously mapped RFLP markers from which these SNPs were derived were compared. Results from these experiments indicate that DHPLC can be efficiently employed in analysing SNPs on a high-throughput scale.Key words: denaturing high performance liquid chromatography, doubled-haploid lines, restriction fragment length polymorphism, genetic mapping, molecular markers.
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LIPSA, Florin Daniel, Rod SNOWDON, Benjamin WITTKOP, and Wolfgang FRIEDT. "QUANTITATIVE GENETIC ANALYSIS OF PHENOLIC ACIDS IN OILSEED RAPE MEAL." Journal of Applied Life Sciences and Environment 55, no. 2 (190) (January 16, 2023): 111–23. http://dx.doi.org/10.46909/alse-552051.
Full textAbstract:
Rapeseed meal, a by-product of oilseed extraction related to the agri-food and biofuel industries due to its favourable composition of essential amino acids, is currently utilised for animal feed. In this study, 166 doubled haploid (DH) rapeseed lines from the segregating Brassica napus doubled haploid population YE2-DH were genetically and chemically analysed for phenolic acids. The relationship between seed colour and phenolic acid fractions in B. napus was investigated using these analyses to improve the quality of rapeseed meal. High-performance liquid chromatography assays were used to estimate phenolic acid content, and the outcomes were used to identify quantitative trait loci (QTL). Nine quantitative feature loci for three distinct phenolic acid compounds were mapped to seven linkage groups. A minor QTL for sinapine was located on linkage group C05 in the same interval as the QTL for seed colour. On chromosome A09, two loci for phenolic acids colocalised with the main QTL for seed colour. Closely linked molecular markers for the target traits (seed colour, phenolic acids) identified during this study could be useful tools for breeding new oilseed rape cultivars with lower levels of antinutritive compounds.
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Song, Xianliang, Kai Wang, Wangzhen Guo, Jun Zhang, and Tianzhen Zhang. "A comparison of genetic maps constructed from haploid and BC1 mapping populations from the same crossing between Gossypium hirsutum L. and Gossypium barbadense L." Genome 48, no. 3 (June 1, 2005): 378–90. http://dx.doi.org/10.1139/g04-126.
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Simple sequence repeat (SSR) genetic maps have been separately constructed based on doubled haploid (DH) and (or) haploid and BC1 populations from the same cross between Gossypium hirsutum L. 'TM-1' and Gossypium barbadense L. 'Hai7124'. The BC1 population was produced by pollinating individual plants of the 'TM-1' × 'Hai7124' F1 with 'TM-1', whereas the DH and (or) haploid population developed from the offspring of Vsg × ('TM-1' × 'Hai7124'). Vsg is a virescently marked semigamy line of Gossypium barbadense L. Pima. The BC1 map included 34 linkage groups with an average distance between markers of 9.80 cM (Kosambi, K) and covered 4331.2 cM (K) or approximately 78.7% of the tetraploid cotton genome constructed using 440 SSR and 2 morphological marker genes. Among them, 26 were assigned to 20 chromosomes, 7 to A or D subgenomes, and 1 was unassigned. The haploid map comprised 444 SSR markers mapped to 40 linkage groups with an average distance of 7.35 cM (K) between markers, covering 3262.9 cM (K) or approximately 60.0% of the tetraploid genome. Twenty-nine linkage groups were assigned to all 19 identified chromosomes, 10 to A or D subgenomes, and 1 was unassigned. Fairly good collinearity of marker order was observed along most of the chromosomes or linkage groups. Significant differences in recombination between maps was observed at the chromosomal and genomic level and possible reasons were discussed. Map comparison and combined data provided an essential basis for further mapping of interested genes and QTLs and for studies of diversity, population structure, and phylogeny in Gossypium species.Key words: cotton, SSR, comparative mapping, semigamy.
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Ren, Wei, Xiaoping Gong, Kun Li, Hongwei Zhang, Fanjun Chen, and Qingchun Pan. "Recombination Pattern Characterization via Simulation Using Different Maize Populations." International Journal of Molecular Sciences 21, no. 6 (March 23, 2020): 2222. http://dx.doi.org/10.3390/ijms21062222.
Full textAbstract:
Efficient recombination is critical to both plant breeding and gene cloning. However, almost all traditional recombination studies and genetic improvements require the slow and labor-intensive population construction process, and little is known about the recombination characteristics of populations of different types, generations, and origins. Here, we provide a simple and efficient simulation method for population construction based on doubled haploid (DH) and intermated B73 × Mo17 maize (IBM) populations to predict the recombination pattern. We found that the chromosomes had 0, 1, 2, and 3 recombination events that occurred at rates of 0.16, 0.30, 0.23, and 0.15, respectively, in the DH and the recombination rate of each chromosome in the IBM population ranged from 0 to 12.1 cM per 125 kb. Based on the observed recombination parameters, we estimated the number of recombination events and constructed the linkage maps of the simulated DH and recombination inbred line (RIL) populations. These simulated populations exhibited similar recombination patterns compared with the real populations, suggesting the feasibility of this simulation approach. We then compared the recombination rates of the simulated populations of different types (DH induced or self-crossed), generations, and origins (using the 8, 16, and 32 multiparent advanced generation intercross (MAGIC) populations), and suggested a rapid and cost-effective population construction procedure for breeders and geneticists, while maintaining an optimal recombination rate. This study offers a convenient method for optimizing the population construction process and has broader implications for other crop species, thereby facilitating future population studies and genetic improvement strategies.
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Powell, W., W. T. Thomas, D. M. Thompson, J. S. Swanston, and R. Waugh. "Association between rDNA alleles and quantitative traits in doubled haploid populations of barley." Genetics 130, no. 1 (January 1, 1992): 187–94. http://dx.doi.org/10.1093/genetics/130.1.187.
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Abstract Doubled haploids (DH) were generated from reciprocal F1 hybrids which were heterozygous for alleles at the Nor-H3 locus on chromosome 5H of barley. The r-DNA alleles did not deviate significantly from the expected 1:1 ratio and the DH progenies were classified into two groups based on the allelic constitution of the Nor-H3 locus. The DHs were grown in a randomized, replicated field experiment and a range of agronomic and quality traits were recorded. The Nor-H3 locus was associated with a significant portion of the genetic variation for: yield, thousand corn weight, water sensitivity and milling energy requirement of the grain. However, the magnitude of the differences between groups was dependent on the direction of the cross. The milling energy requirement of the grain was consistently associated with alleles at the Nor-H3 locus. These results are presented in relation to the dynamics of rDNA evolution and variability. The potential of molecular markers in conjunction with doubled haploids to map quantitative traits in barley is also discussed.
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CIULCA, Sorin, Aurel GIURA, and Adriana CIULCA. "Grain size and other agronomical traits variation in a winter wheat population of doubled haploid lines." Notulae Botanicae Horti Agrobotanici Cluj-Napoca 48, no. 3 (September 30, 2020): 1369–86. http://dx.doi.org/10.15835/nbha48312019.
Full textAbstract:
In wheat, the size of the grain, respectively its dimensions as well as degree of filled, are important characteristics on which depends both the weight of the grain and yield of flour, the quality of milling and baking as well as the production capacity of the respective genotype. This paper presents the results obtained by studying for three years, under field condition, 85 doubled haploid (DH) lines obtained from the F1’s of ‘G.603-86’ (large grains genotype) × ‘F.132’ (normal grains genotype) crosses using biotechnological Zea system. The environmental conditions of the three years had an important contribution on the genotype × year interaction, which showed also a higher influence on 1000 kernel weight (TKW). The variability of plant height and ear emergence data was also affected to a similar extent by this interaction. Based on the performed results and analyses, were highlighted lines which show high and stable values of TKW (54-64 g), associated with a plants height of approximately 85-100 cm and an ear emergence from May 11 to 17, under some climatic conditions similar to the period of study. These doubled haploids lines can be considered as promising genotypes for using in wheat breeding programs in order to improve yield performances under temperate continental climate conditions.
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Dahleen, L. S., D. L. Hoffman, J. Dohrmann, R. Gruber, and J. Franckowiak. "Use of a subset of doubled-haploid lines for RAPD interval mapping in barley." Genome 40, no. 5 (October 1, 1997): 626–32. http://dx.doi.org/10.1139/g97-082.
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Molecular markers have been used in barley to locate genes and quantitative trait loci. Only a few RAPD markers have been located on barley marker maps. The objectives of this study were (i) to place RAPD markers in specific intervals on the barley linkage map developed from the cross Steptoe (S) × Morex (M), (ii) to examine the distribution of RAPD markers, and (iii) to compare markers amplified by Taq DNA polymerase with those amplified by the Stoffel fragment of Taq DNA polymerase. Screening of DNA from S and M with 362 decamer primers identified 85 that amplified 127 reliable RAPDs. A subset of 15 doubled-haploid (DH) lines from the 150 DH line mapping population was used to place these RAPD markers in intervals on the SM map. This subset can be used for rapid placement of any new markers on the SM linkage map. Most of the RAPD markers were dominant but four codominant RAPDs were identified. The RAPDs were not evenly distributed, with many clustered around the centromeric region of each chromosome. Two of these clusters were located in intervals larger than 15 cM. Testing of 38 to 42 additional DH lines provided more precise placement of eight of the markers in these clusters. Reliable RAPDs were detected with 44% of the primers tested with the Stoffel fragment, but with only 17% of the primers tested with Taq DNA polymerase. These RAPDs provide additional markers for use in barley improvement.Key words: Hordeum vulgare, interval mapping, molecular markers.
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Wang, Nan, Hui Wang, Ao Zhang, Yubo Liu, Diansi Yu, Zhuanfang Hao, Dan Ilut, et al. "Genomic prediction across years in a maize doubled haploid breeding program to accelerate early-stage testcross testing." Theoretical and Applied Genetics 133, no. 10 (June 30, 2020): 2869–79. http://dx.doi.org/10.1007/s00122-020-03638-5.
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Abstract Key message Genomic selection with a multiple-year training population dataset could accelerate early-stage testcross testing by skipping the first-stage yield testing, which significantly saves the time and cost of early-stage testcross testing. Abstract With the development of doubled haploid (DH) technology, the main task for a maize breeder is to estimate the breeding values of thousands of DH lines annually. In early-stage testcross testing, genomic selection (GS) offers the opportunity of replacing expensive multiple-environment phenotyping and phenotypic selection with lower-cost genotyping and genomic estimated breeding value (GEBV)-based selection. In the present study, a total of 1528 maize DH lines, phenotyped in multiple-environment trials in three consecutive years and genotyped with a low-cost per-sample genotyping platform of rAmpSeq, were used to explore how to implement GS to accelerate early-stage testcross testing. Results showed that the average prediction accuracy estimated from the cross-validation schemes was above 0.60 across all the scenarios. The average prediction accuracies estimated from the independent validation schemes ranged from 0.23 to 0.32 across all the scenarios, when the one-year datasets were used as training population (TRN) to predict the other year data as testing population (TST). The average prediction accuracies increased to a range from 0.31 to 0.42 across all the scenarios, when the two-years datasets were used as TRN. The prediction accuracies increased to a range from 0.50 to 0.56, when the TRN consisted of two-years of breeding data and 50% of third year’s data converted from TST to TRN. This information showed that GS with a multiple-year TRN set offers the opportunity to accelerate early-stage testcross testing by skipping the first-stage yield testing, which significantly saves the time and cost of early-stage testcross testing.
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Cherif, M., S. Rezgui, P. Devaux, and M. Harrabi. "Genetic analysis of net blotch resistance in a two-row × six-row cross of barley, using doubled-haploid lines." Canadian Journal of Plant Science 88, no. 1 (January 1, 2008): 257–66. http://dx.doi.org/10.4141/cjps06050.
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The effect of spike type on net blotch resistance is not fully understood in barley (Hordeum vulgare L.). A doubled-haploid barley population derived from a cross between a susceptible two-row (Roho) and a resistant six-row (line 90) genotypes was used to study the genetics of net blotch resistance and to determine the effect of spike type on net blotch resistance at the adult plant growth stage across three environments. Net blotch rating was evaluated using a mass disease index, area under the disease progress curve and the apparent infection rate. Partial resistance to Pyrenophora teres was observed in many DH lines and in the parental line 90 in the three environments. This result indicated that selecting for partial resistance is feasible under severe net blotch conditions where differential responses among DH lines were noted as in Mograne in 2003–2004. The normality test and/or the means comparison method suggested that additive × additive epistasis effects influenced the expression of all disease parameters in the three environments. Both the coefficient of skewness and the number of transgressive lines indicate the presence of a complementary gene interaction for most disease parameters. Results showed that two-row lines were particularly associated with net blotch resistance in Mograne 2002–2003 and in Tunis greenhouse 2004. A strategy for improving the level of quantitative resistance to P. teres in later generations is recommended. Key words: Hordeum vulgare, doubled-haploid population, quantitative resistance, Pyrenophora teres, net blotch, genetic analysis
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Torres, Gisele Abigail Montan, Sandra Maria Mansur Scagliusi, Márcia Soares Chaves, and Luciano Consoli. "Glutenin analysis for the safe screening of self-pollinated wheat seeds when developing doubled-haploid populations." Pesquisa Agropecuária Brasileira 53, no. 5 (May 2018): 646–50. http://dx.doi.org/10.1590/s0100-204x2018000500014.
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Abstract: The objective of this work was to apply glutenin analysis, as a simple and reliable method, to identify self-pollinated wheat (Triticum aestivum) seeds in F1 crosses, when developing mapping populations using doubled-haploid (DH) technology. F1 seeds were subjected to glutenin analyses using gel electrophoresis, to verify and confirm their heterozygotic profiles. Glutenin analyses were carried out using one half of the endosperm of each of the 87 F1 seeds. The other half of the endosperm was used to develop the mapping population through DHs. Plants with band patterns different from the expected ones were discarded. Although the incidence of self-pollinated seeds was relatively low (only 8%), the screening of F1 heterozygotic profiles is extremely important, particularly when creating reliable mapping populations.
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Khumalo, Thobeka Philile, Tsepiso Hlongoane, Annelie Barnard, and Toi John Tsilo. "Genomic Regions Influencing Preharvest Sprouting Tolerance in Two Doubled-Haploid Wheat Populations (Triticum aestivum L.)." Agronomy 12, no. 4 (March 29, 2022): 832. http://dx.doi.org/10.3390/agronomy12040832.
Full textAbstract:
The current and projected climate change that is represented by increasing temperatures and humidity levels and irregular rainfall patterns promotes the occurrence of preharvest sprouting (PHS) in wheat. PHS results in significant economic losses, globally, which necessitates the need for high-yielding cultivars with increased PHS tolerance; hence, this study was conducted. The current study evaluated two doubled-haploid (DH) wheat populations of Tugela-Dn × Elands and Elands × Flamink across six environments in the Free State Province of South Africa to select genotypes with increased PHS tolerance and further map the underlying loci. Significant effects of DH lines (194) and environments (6) were observed for PHS tolerance. The results of this study validate previous findings that PHS is only expressed when environmental conditions are conducive. Quantitative trait loci (QTL) mapping using single-nucleotide polymorphism (SNP) and silicoDArT markers revealed three additive QTLs with major effects on chromosomes 5B and 7B, and these QTLs were detected more than once, when conditions were favourable. These QTLs explained a phenotypic variation (PVE) varying between 10.08% and 20.30% (LOD = 2.73–3.11). About 16.50% of DH lines performed to the level of Elands (the PHS-tolerant parent) and are recommended for further selection in a pre-breeding or breeding programme. The findings of this study are expected to expedite the on-going breeding efforts for PHS tolerance in winter wheat, which will facilitate the development of PHS-tolerant cultivars adapted to the South African environment.
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Sourdille, P., J. W. Snape, T. Cadalen, G. Charmet, N. Nakata, S. Bernard, and M. Bernard. "Detection of QTLs for heading time and photoperiod response in wheat using a doubled-haploid population." Genome 43, no. 3 (June 1, 2000): 487–94. http://dx.doi.org/10.1139/g00-013.
Full textAbstract:
The genetic basis of heading time in wheat (Triticum aestivum L.) was investigated through the study of flowering under normal autumn sown field conditions as well as photoperiod responses under a controlled environment. Quantitative trait loci (QTLs) for these traits were mapped in a doubled-haploid (DH) population derived from a cross between the wheat cultivars 'Courtot' and 'Chinese Spring'. A molecular marker linkage map of this cross that was previously constructed based on 187 DH lines and 380 markers was used for QTL mapping. The genome was well covered (85%) except for chromosomes 1D and 4D, and a set of anchor loci regularly spaced over the genome (one marker each 15.5 cM) was chosen for marker regression analysis. The presence of a QTL was declared at a significance threshold of alpha = 0.005. The population was grown under field conditions in Clermont-Ferrand, France during two years (1994-1995), in Norwich, U.K. over one year (1998), and also under controlled environments in Norwich. For each trait, between 2 and 4 QTLs were identified with individual effects ranging between 6.3% and 44.4% of the total phenotypic variation. Two QTLs were detected that simultaneously affected heading time and photoperiod response. For heading time, these two QTLs were detected in more than one year. One QTL located on chromosome arm 2BS near the locus Xfbb121-2B, co-segregated with the gene Ppd-B1 known to be involved in photoperiod response. This chromosome region explained a large part of the variation (23.4-44.4% depending on the years or the traits). Another region located on chromosome arm 7BS between the loci Xfbb324-7B and Xfbb53-7B also had a strong effect (7.3-15.3%). This region may correspond to a QTL for earliness per se.Key words: molecular markers, Triticum aestivum, Ppd, Vrn.
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Farnham, Mark W. "Doubled-haploid Broccoli Production Using Anther Culture: Effect of Anther Source and Seed Set Characteristics of Derived Lines." Journal of the American Society for Horticultural Science 123, no. 1 (January 1998): 73–77. http://dx.doi.org/10.21273/jashs.123.1.73.
Full textAbstract:
Using anther culture to generate doubled-haploid (DH) homozygous lines for use as parents in F1 hybrid crosses has become a common practice in breeding broccoli (Brassica oleracea L. Italica Group). During anther culture and subsequent embryogenesis and plant regeneration, polyploidization of microspore-derived embryos may not occur or it may occur accompanied by a doubling, tripling, quadrupling, octupling, or irregular polyploidization of the genome. Thus regenerants from the process can be haploids, diploids, triploids, tetraploids, octaploids, or aneuploids. The objectives of this research were to 1) conduct repeat cycles of broccoli anther culture using a group of F1 hybrids as anther donors and develop populations of regenerants; 2) analyze resulting populations using DNA flow cytometry and determine the influence of F1 source on frequency of different ploidy levels among regenerants; and 3) compare seed set in broccoli inbreds developed in a traditional selfing program compared to seed set in DH broccoli derived from anther culture. In two cycles (1994 and 1995) of anther culture, anther-derived populations of regenerants were developed using the F1 hybrids `Marathon', `Everest', `High Sierra', and `Futura' as sources of anthers. In 1994, `Everest', `High Sierra', and `Futura' yielded populations that included 2% to 7% haploids, 53% to 56% diploids, 32% to 38% tetraploids, and 5% to 6% other types. `Marathon'-derived regenerants were 5% haploid, 78% diploid, 15% tetraploid, and 2% other, showing significantly more diploids. In 1995, `Marathon' regenerants again included significantly more diploids and fewer tetraploids than those derived from other F1 sources, confirming that the genotype of the anther source affects the frequency of a particular ploidy level among regenerants derived from culture. In manual self-pollinations of 1994 regenerants, only diploids and rare tetraploids set seed. When plants that set no seed were discounted, seed production following manual self pollinations of 1995 regenerants was not significantly different from that of traditional inbreds derived from the same F1 sources.
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Zhao, L., K. Zhang, B. Liu, and J. Tian. "Detection of quantitative trait loci for paste viscosity characteristics based on the doubled haploid progeny from a cross between two Chinese wheat varieties." Canadian Journal of Plant Science 89, no. 5 (September 1, 2009): 837–44. http://dx.doi.org/10.4141/cjps08201.
Full textAbstract:
In order to understand the genetic basis of starch pasting viscosity characteristics (the RVA profile, which is produced by the Rapid Visco Analyser) of wheat grain samples, a doubled haploid (DH) population (Huapei 3 × Yumai 57; Yumai 57 is superior to Huapei 3 for RVA profile parameters) and a linkage map consisting of 324 marker loci were used to search QTL. This program was based on mixed linear models and allowed simultaneous mapping of additive effect QTL, epistatic QTL, and QTL × environment interactions (QE). Mapping analysis produced a total of 35 QTL for 6 RVA profile parameters with a single QTL explaining 0.91-21.34% of phenotypic variations. The 35 QTL were distributed on 15 chromosomes. The QBd-4A had the most significant additive effect, accounting for 21.34% of the phenotypic variance. Two QTL clusters for RVA profile parameters were located on chromosomes 2A and 4A, respectively. The information obtained in this study should be useful for manipulating the QTL for RVA profiles parameters by molecular assisted selection (MAS) in wheat breeding programs.Key words: Doubled haploid population, paste viscosity characteristics, rapid visco analyser, quantitative trait loci, wheat (Triticum aestivum L.)
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Mrva, K., and D. J. Mares. "Quantitative trait locus analysis of late maturity a-amylase in wheat using the doubled haploid population Cranbrook Halberd." Australian Journal of Agricultural Research 52, no. 12 (2001): 1267. http://dx.doi.org/10.1071/ar01047.
Full textAbstract:
Mapping of the late maturity α-amylase (LMA) gene using quantitative trait locus (QTL) analysis represents an important step in identification of potential molecular markers that would greatly improve efficiency and accuracy of screening for LMA. QTL controlling the expression of LMA in wheat were detected in a doubled haploid (DH) cross/population derived from wheat (Triticum aestivum L. em. Thell) cultivars Cranbrook (LMA source) and Halberd (non-LMA). The DH population and parents were sown in replicated trials at Narrabri with sowing times differing by 2 weeks. Cool temperature treatment of detached tillers was used to induce expression of LMA in lines carrying the defect. The number of grains in ripe, treated tillers that contained high pI (malt, germination type) α-amylase isozymes was measured using an ELISA antibody kit highly specific for high pI isozymes. QTL analyses were conducted separately for each sowing, but results from both sowings were consistent and indicated that there was a highly significant (P < 0.001) QTL on the long arm of chromosome 7B (accounting for 31% of the variation in the first experiment), with Cranbrook contributing the higher value allele. A second QTL that accounted for 13% of the variation was found close to the centromere on chromosome 3B. Although it was less important than the QTL on 7B it was nevertheless still significant (P < 0.05).
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Barchi, Lorenzo, Sergio Lanteri, Ezio Portis, Anikò Stàgel, Giampiero Valè, Laura Toppino, and Giuseppe Leonardo Rotino. "Segregation distortion and linkage analysis in eggplant (Solanum melongena L.)." Genome 53, no. 10 (October 2010): 805–15. http://dx.doi.org/10.1139/g10-073.
Full textAbstract:
An anther-derived doubled haploid (DH) population and an F2 mapping population were developed from an intraspecific hybrid between the eggplant breeding lines 305E40 and 67/3. The former incorporates an introgressed segment from Solanum aethiopicum Gilo Group carrying the gene Rfo-sa1, which confers resistance to Fusarium oxysporum ; the latter is a selection from an intraspecific cross involving two conventional eggplant varieties and lacks Rfo-sa1. Initially, 28 AFLP primer combinations (PCs) were applied to a sample of 93 F2 individuals and 93 DH individuals, from which 170 polymorphic AFLP fragments were identified. In the DH population, the segregation of 117 of these AFLPs as well as markers closely linked to Rfo-sa1 was substantially distorted, while in the F2 population, segregation distortion was restricted to just 10 markers, and thus the latter was chosen for map development. A set of 141 F2 individuals was genotyped with 73 AFLP PCs (generating 406 informative markers), 32 SSRs, 4 tomato RFLPs, and 3 CAPS markers linked to Rfo-sa1. This resulted in the assignment of 348 markers to 12 major linkage groups. The framework map covered 718.7 cM, comprising 238 markers (212 AFLPs, 22 SSRs, 1 RFLP, and the Rfo-sa1 CAPS). Marker order and inter-marker distances in this eggplant map were largely consistent with those reported in a recently published SSR-based map. From an eggplant breeding perspective, DH populations produced by anther culture appear to be subject to massive segregation distortion and thus may not be very efficient in capturing the full range of genetic variation present in the parental lines.
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Janská, A., S. Zelenková, M. Klíma, M. Vyvadilová, and T. I. Prášil. "Freezing tolerance and proline content of in vitro selected hydroxyproline resistant winter oilseed rape." Czech Journal of Genetics and Plant Breeding 46, No. 1 (March 4, 2010): 35–40. http://dx.doi.org/10.17221/52/2009-cjgpb.
Full textAbstract:
Twelve doubled haploid (DH) winter oilseed rape plants with altered levels of proline and/or freezing tolerance were obtained by in vitro selection for resistance to trans-4-hydroxy-l-proline (Hyp) in five segregating microspore populations. No significant response to selection either in proline content or in freezing tolerance, compared with the non-selected control populations, was observed. When data from all examined materials were combined, a weak correlation between proline content and freezing tolerance was observed.
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Lee, Gyu-Ho, In-Kyu Kang, and Kyung-Min Kim. "Mapping of Novel QTL Regulating Grain Shattering Using Doubled Haploid Population in Rice (Oryza sativaL.)." International Journal of Genomics 2016 (2016): 1–8. http://dx.doi.org/10.1155/2016/2128010.
Full textAbstract:
The critical evolutionary step during domestication of major cereals was elimination of seed shattering because the easy-to-shatter trait in wild relatives results in a severe reduction in yield. In this study, we analyzed the QTLs associated with shattering employing a high-density genetic map in doubled haploid (DH) population of rice (Oryza sativaL.). A genetic linkage map was generated with 217 microsatellite markers spanning 2082.4 cM and covering 12 rice chromosomes with an average interval of 9.6 cM between markers based on 120 DHLs derived from a cross between Cheongcheong indica type cultivar and Nagdong japonica type cultivar. In the QTL analysis, five QTLs pertaining to the breaking tensile strength (BTS) were detected in 2013 and 2015. Two regions of the QTLs related to BTS on chromosome 1 and chromosome 6 were detected. Several important genes are distributed in 1 Mbp region of the QTL on chromosome 6 and they are related to the formation of abscission layer. We decide to name this QTLqSh6and the candidate genes in theqSh6region can be employed usefully in further research for cloning.
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Lantos, Csaba, Szandra Purgel, Katalin Ács, Bernadett Langó, Lajos Bóna, Krisztina Boda, Ferenc Békés, and János Pauk. "Utilization of in Vitro Anther Culture in Spelt Wheat Breeding." Plants 8, no. 10 (October 22, 2019): 436. http://dx.doi.org/10.3390/plants8100436.
Full textAbstract:
The efficiency of in vitro anther culture was screened in a full diallel population of four spelt wheat genotypes and ten F1 hybrids. Genotype dependency was observed based on the data of embryo-like structures (ELS), green-, albino plantlets. In the diallel population and ten F1 hybrids, the green plantlets production ranged from 13.75 to 85.00 and from 6.30 to 51.00, respectively. The anther culture-derived plants of F1 hybrids were grown up in the nursery. At the harvest, 436 spontaneous doubled haploid (DH) plants were identified among the 1535 anther culture-derived transplanted and grown up individual plants. The mean of spontaneous rediploidization was 28.4% which ranged from 9.76% to 54.24%. In two consecutive years, the agronomic values of ‘Tonkoly.pop1’ advanced line were compared with seven DH lines of ‘Tonkoly.pop1’ in the nursery. The DH lines achieved competitive values in comparison with ‘Tonkoly.pop1’ advanced line based on the 11 measured parameters (heading date, plant height, yield, hardness, width and length of seed, TKW, hulling yield, flour yield, protein and wet gluten content). These observations presage the efficient utilization of anther culture in spelt wheat breeding.
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WINDARSIH, GUT, and DWINITA WIKAN UTAMI. "Evaluation of neck blast resistance and agronomical performances on double haploid rice population in greenhouse and endemic field." Nusantara Bioscience 9, no. 4 (November 2, 2017): 371–77. http://dx.doi.org/10.13057/nusbiosci/n090406.
Full textAbstract:
Windarsih G, Utami DW. 2017. Evaluation of neck blast resistance and agronomical performances on double haploid rice population in greenhouse and endemic field. Nusantara Bioscience 9: 371-377. Blast disease caused by fungal Pyricularia grisea Sacc. is one of the most destructive diseases of rice in the world. The development of blast-resistant rice varieties will be essential to control this disease. This research aimed (i) to compare the resistance response to neck-blast among DH lines from double cross IR54/Parekaligolara//Bio110/Markuti and the differential varieties against three selected Indonesian blast races in greenhouse, (ii) to identify the gene(s) that caused the resistance to neck-blast based on the association between the resistance response and the genotype evaluation using molecular markers linked to Pi1, Pi33, Pib, Pir4 and Pir7 genes, and (iii) to evaluate the resistance response to leaf and neck blast on DH lines in endemic field (Sukabumi) and the agronomical performance of selected DH lines in optimum field in Ciasem of Subang, West Java, Indonesia during December 2013 to March 2014. Eleven double haploid lines from double-crossing IR54/Parekaligolara//Bio110/Markuti, the differential varieties as resistant control and the US2 variety for susceptible control were observed for neck-blast resistance response to three blast races in greenhouse and endemic field (Sukabumi), while the agronomical performances were observed in field of Ciasem-Subang. The results based on the genotyping evaluation, leaf and neck blast resistance, either in greenhouse and endemic location, and the agronomical performance in field showed that 5 selected double haploid lines had leaf and neck blast resistance and good performance on field trial. Thus they are promising for use either for further testing forwarding into releasing variety or used as donor for further blast resistant breeding activities.
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Lashermes, P., M. C. Combes, N. S. Prakash, P. Trouslot, M. Lorieux, and A. Charrier. "Genetic linkage map of Coffea canephora: effect of segregation distortion and analysis of recombination rate in male and female meioses." Genome 44, no. 4 (August 1, 2001): 589–95. http://dx.doi.org/10.1139/g01-041.
Full textAbstract:
Two complementary segregating plant populations of Coffea canephora were produced from the same clone. One population (DH) comprised 92 doubled haploids derived from female gametes, while the other population (TC) was a test cross consisting of 44 individuals derived from male gametes. Based on the DH population, a genetic linkage map comprising 160 loci was constructed. Eleven linkage groups that putatively correspond to the 11 gametic chromosomes of C. canephora were identified. The mapped loci included more than 40 specific sequence-tagged site markers, either single-copy RFLP probes or microsatellites, that could serve as standard landmarks in coffee-genome analyses. Furthermore, comparisons for segregation distortion and recombination frequency between the two populations were performed. Although segregation distortions were observed in both populations, the frequency of loci exhibiting a very pronounced degree of distortion was especially high in the DH population. This observation is consistent with the hypothesis of strong zygotic selection among the DH population. The recombination frequencies in both populations were found to be almost indistinguishable. These results offer evidence in favour of the lack of significant sex differences in recombination in C. canephora.Key words: coffee, mapping, sex differences, segregation distortion, recombination frequency.
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Guo, Gang, Shuhao Xu, Hao Chen, Yuanfeng Hao, and Hailiang Mao. "QTL Mapping for Wheat Seed Dormancy in a Yangmai16/Zhongmai895 Double Haploid Population." Plants 12, no. 4 (February 8, 2023): 759. http://dx.doi.org/10.3390/plants12040759.
Full textAbstract:
Pre-harvest sprouting (PHS) of wheat reduces grain yield and quality, and it is strongly affected by seed dormancy. Therefore, identification of quantitative trait loci (QTL) for seed dormancy is essential for PHS resistance breeding. A doubled haploid (DH) population, consisting of 174 lines from the cross between Yangmai16 (YM16) and Zhongmai895 (ZM895) was used to detect QTLs for seed dormancy and grain color. For seed dormancy, a total of seven QTLs were detected on chromosomes 2A, 3A, 3D, 4D, 5B and 5D over four environments, among which Qdor.hzau-3A, Qdor.hzau-3D.1 and Qdor.hzau-3D.2 were stably detected in more than two environments. For grain color, only two QTLs, Qgc.hzau-3A and Qgc.hzau-3D were detected on chromosomes 3A and 3D, which physically overlapped with Qdor.hzau-3A and Qdor.hzau-3D.1, respectively. Qdor.hzau-3D.2 has never been reported elsewhere and is probably a novel locus with allelic effect of seed dormancy contributed by weakly dormant parent ZM895, and a KASP marker was developed and validated in a wheat natural population. This study provides new information on the genetic dissection of seed dormancy, which may aid in further improvement for marker-assisted wheat breeding for PHS resistance.