Journal articles on the topic 'Gibberellic acid 18'

Mini propagation is a new method to produce potato. A factorial experiment based on completely randomized block design with three replications was conducted to investigate the effect of two temperature levels (18 and 25?C) and six hormone treatments (H1: 0% of ethanol + 0 mg/l of gibberellic acid, H2: 0% of ethanol + 10 mg/l of gibberellic acid, H3: 0.5% of ethanol + 0 mg/l of gibberellic acid, H4: 0.5% of ethanol + 10 mg/l of gibberellic acid, H5: 0.5% of ethanol + 20 mg/l of gibberellic acid, H6: 0.5% of ethanol + 30 mg/l of gibberellic acid) on mini tubers of two varieties of potato (Agria and Sant?). The longest sprouts were about 14.13 mm long and they were produced by Sant? variety at 18?C and H1 hormone level. Sprouting percentage was higher in Sant? (75.69%) than in Agria (59.72%). The highest average percentage of sprouted tubers (95%) was achieved at the temperature of 18?C and with H4 hormone treatment. Sant? had the shortest dormancy duration by using H1 hormone level at 18?C. Applying H6 hormone level at 18?C produced more sprouts per tuber in Sant?. Sant? was better than Agria with or without hormone treatment in respect of all measured traits. Higher GA concentration accelerates tuber sprouting in both varieties.

Gibberellic acid is a phytohormone that triggers the germination of seeds in a state of dormancy. Through the quantification of this hormone, the physiological condition of seeds of economic importance can be studded. In this work we validated a High-Performance Liquid Chromatography method to quantify gibberellic acid in germinated maize (Zea mays L.) seeds. Chromatographic conditions included the use of a C-18 reversed-phase column, acetonitrile-formic acid (1 : 9 %) as the mobile phase, flow of 0.5 mL·min-1, and detection at 195 nm. We evaluated our method for seven analytical parameters. The method was linear for gibberellic acid concentrations from1.0 mg·kg-1 to 50.0 mg·kg-1. The method’s limits were 0.3 mg·kg-1 and1.0 mg·kg-1 for detection and quantification, respectively. The method was highly precise; we obtained variable but low relative standard deviations (2.62 % - 12.66 %) for the studied gibberellic acid concentrations. We assessed accuracy through recovery percentages, ranging from 52.85 % - 63.68 %, for three gibberellic acid concentrations. We conclude that our analytical method can be used to measure gibberellic acid during the early stages of maize germination. In addition, the method could be used for the analysis of other types of plant matrices.

Rhizomes of <i>Zantedeschia</i>, 15-18 cm in circumference with leaf buds 0.5-1 cm in length, were planted into 20-cm pots on 15 May 2006 into a medium consisting of peat with a pH of 6.2, enriched with a slow-release fertiliser Osmocote Plus (3-4M) and mixed with fresh shredded pine bark at a rate of 3:1 (v:v). Before planting, the rhizomes were soaked for 20 minutes in a water solution of gibberellic acid at a concentration of 150 mg x dm^-3, or sprayed with the same concentration once, twice or three times, each time after thorough drying. For each round of spraying, 100 ml of the solution were used. Gibrescol 10 MG was applied. Gibberellic acid had a similar effect, whether applied in the form of a solution for soaking or spraying of rhizomes. The number of sprayings of rhizomes had no effect on the effectiveness of gibberellic acid. In the cultivar 'Black Magic', rhizome spraying caused earlier flowering, while in 'Cameo' a similar effect was obtained by soaking the rhizomes in gibberellic acid. Gibberellic acid had no effect on the quality of flowers and the number of leaves. Gibberellic acid had a good effect on the index of leaf greenness in the cultivars under study.

The lowest pods on common bean (Phaseolus vulgaris) are on or near the ground. Yields may improve by raising these pods to reduce yield loss, especially with direct harvest. The objective of this field study was to use gibberellic acid (GA3) to raise lower pods and increase yield. Seeds of cultivars Poncho (Type III, pinto) and Matterhorn (Type II, great northern) were dipped in GA3 at 0, 125, 500, and 2000 ppm and planted in 30-inch rows (2005). Stem elongation was promoted, but emergence and yield were decreased especially for ‘Poncho’. In foliar tests in 30-inch rows (2005 and 2006), GA3 was applied to newly expanded unifoliolate leaves. Doses were 0, 0.5, 2, and 8 ppm for ‘Poncho’ and 0, 31.25, 125, and 500 ppm for ‘Matterhorn’. The higher doses raised the low pod by 2 inches, and yields harvested conventionally were increased from 14% to 18%. In 2007, ‘Poncho’ and ‘Matterhorn’ unifoliolate leaves were treated with GA3 at 0, 2, and 4 ppm, and 0, 62.5, and 125 ppm, respectively, and then portions of each plot were harvested either manually, conventionally, or directly. Planting was in 22- and 30-inch row spacing. Lower pods were raised by ≈1 inch by GA3. Yields from conventional and direct harvest were increased by foliar GA3 application for both cultivars and both row spacings. Yield from directly harvested GA3-treated plots was comparable to that from untreated conventionally harvested plots. GA3 may play a role in increasing yield from directly harvested common bean in conjunction with genetic and mechanical improvements.

The exercise of using (PGRs), especially Gibberellic acid and in field of agriculture has become commercialized in some of the country including Pakistan. Number of different crops are being treated by farmers mostly vegetables; currently evaluated in rice crop through foliar application at different intervals to evaluate their efficiency at different doses. Results revealed that there was no significant difference in crop maturity compared with control. Plant height was variable among treated plots, highest plant height was recorded (121.2cm) in 2017-18 experiment in T-3 Gibberellic acid @ 12grams/acre while minimum (96.2cm) in 2016-17 in T-7 Control. Tillers/hill was increased, and maximum counted 18.5/hill in T-3 Gibberellic acid @ 10gms/acre whereas 11.9/hill was recorded in T-7 Control. Grain filling was obvious recorded with significance; counted 83 percent in T-5 Naphthalene acetic acid treated 100ml/acre whereas average minimum (71.3%) was recorded in T-7 Control. Not only plant development was modified by the treatments but yield was also increased average maximum (3228kgs/acre) with 19.61 percent was recorded in T-5 Naphthalene acetic acid @ 100ml/acre. Int. J. Appl. Sci. Biotechnol. Vol 8(3): 318-322

Conditioning is a simple and effective method of post-harvest longevity of both flowers and florists&rsquo; greens. Performing this treatment immediately after harvest by the producer increases the quality of floral products expressed as their post-harvest longevity. The purpose of this study was to assess the influence of four growth regulators from the gibberellin and cytokinin groups applied as a 4-h conditioning treatment of leaf blades and to determine any effects on post-harvest longevity of leaves of Limonium latifolium. The leaves were harvested early in the morning from the department of ornamental plants collection. Selected leaves were fully-developed and had no damage or discolouring. Gibberellic acid, benzyladenine, meta- methoxytopolin and its riboside at the concentrations of 25, 50 and 75 mg/dm³were taken up in a solution for 4-h leaf-conditioning of Limonium latifolium at the temperature of 18&ndash;20&deg;C. After the conditioning treatment the leaves were placed in distilled water. Leaves placed into distilled water immediately after cutting served as control. Gibberellic acid, benzyladenine and topolins applied as leaf conditioning treatment extended the post-harvest longevity of leaves of Limonium latifolium. Examined growth regulators, with the exception of riboside of meta-methoxytopolin, also had a favourable effect on the index of leaf greenness.

Aquilegia × hybrida Sims `Purple' and `Dove' initiated flower buds 5 months after seeding without being exposed to low temperatures. Four experiments were conducted to test the effects of gibberellic acid (GA3), long photoperiod, long photoperiod with a high level of irradiance, and cold treatments on forcing of the two cultivars. Time from treatment to anthesis was reduced by 9 days for defoliated `Purple' plants treated with 250 mg GA3/liter, and by >14 days for defoliated `Dove' plants treated with 125 mg GA3/liter. Defoliated `Purple' or `Dove' plants treated with 18 hours of supplemental high pressure sodium (HPS) light at 250μl mol·m-1·s-2 (18 SH) reached anthesis 14 or 10 days earlier, respectively, after treatment than plants grown under natural daylight (Nat). The 18 SH treatment increased the number of flowers from eight and nine per plant on Nat plants for defoliated `Dove' and `Purple', respectively, to 16 flowers on 18 SH plants. Cold treatments at 4 ± lC did not shorten the interval between treatment and anthesis, but decreased the number of flowers per plant in both cultivars. Chemical name used: gibberellic acid (GA3).

A field experiment was carried out for three crop seasons at Sugarcane Research Station, Nayagarh (Odisha) during spring seasons of 2015-16, 2016-17 and 2017-18 to assess the effect of ethrel and gibberellic acid on growth, yield attributing characters, yield and quality of sugarcane (Saccharum sp. complex). Pooled data of three years study indicated that different treatments with plant growth regulators had significant effect on growth, yield and quality parameters of sugarcane. Germination percent of cane buds was the highest in the treatment involving planting of sugarcane setts after overnight soaking in 100 ppm ethrel solution followed by foliar application of gibberellic acid @35 ppm at 90,120 and 150 days after planting (DAP). Other sugarcane growth parameters, viz. number of tillers and plant heights were significantly higher with the application of growth regulators which produced higher number of millable canes (at harvest) than that of other treatments in the test. Overnight soaking of cane setts in 100 ppm ethrel solution followed by foliar application of gibberellic acid @35 ppm at 90,120 and 150 days after planting also produced significantly higher yield parameters, viz. number of millable cane (84.26’ 000 ha-1), cane length (313.6 cm), cane girth (2.94 cm) and single cane weight (1.64 kg) as compared to conventionally planted sugarcane crop. There was no significant influence on juice quality parameters due to various treatments in this study. However, overnight soaking of setts with 100 ppm ethrel solution followed by foliar application of gibberellic acid @ 35 ppm at 90, 120 and 150 days after planting showed comparatively higher values in all the juice quality parameters. Significantly higher cane and sugar yields of 116.14 t/ha and 12.82 t/ha, respectively were obtained with planting of sugarcane after overnight soaking in 100 ppm ethrel solution followed by gibberellic acid spray @ 35 ppm at 90, 120 and 150 days after planting. The above higher yields were attributed mainly to marked improvement in growth and yield attributes in response to application of plant growth regulators. Therefore, it can be concluded that combined application of ethrel and gibberellic acid had the positive effect to improve the growth parameters, yield and quality of sugarcane.

AbstractLeaves ofAlchemilla mollis(Bauser) Rothm. were the subject of the study. The leaves were harvested early in the morning from the department’s ornamental plant collection. Selected leaves were fully-developed and showed no signs of damage or discolouring. Gibberellic acid (GA3), benzyladenine (BA),meta-methoxytopolin (MemT) and its riboside (MemTR) at concentrations of 25, 50 and 75 mg dm−3were applied in the form of solutions to four-hour leaf-conditioning in the room at a temperature of 18-20°C. After conditioning, the leaves were placed in distilled water. Leaves put into distilled water immediately after cutting served as the control. The post-harvest longevity of leaves ofAlchemilla molliswas 7.2-11.8 days. The conditioning of leaves in gibberellic acid solutions at concentrations of 25-50 mg dm−3, benzyladenine at concentrations of 25 mg dm−3andmeta-methoxytopolin and its riboside at concentrations of 75 mg dm−3extended the post-harvest longevity of leaves by 10.1-81.9%. The conditioning of leaves in gibberellic acid at a concentration of 50 mg dm−3inhibited the degradation of chlorophyll, as indicated by the highest SPAD index values.

Two seed lots of western white pine (Pinusmonticola Dougl.) were treated by various chemical and physical methods to increase their germination. For unstratified seeds, treatments by hydrogen peroxide, kinetin, and gibberellic acid, sulfuric acid, or clipping increased germination (33–53%) over that of the controls (7–16%). Lengthwise cutting of the seed coat and soaking in water or potassium nitrate (KNO3) were not as effective. Germination was fastest and greatest (74–83%) with a combined kinetin plus gibberellic acid treatment, followed by H2O2 and cold stratification for 42 days. A combination of clipping and cold stratification for 30–42 days also gave high germination (68–78%). Germination was better at a constant 18 or 20 °C under continuous light than under an alternating 20:30 °C (dark: light) temperature with an 8 h light: 16 h dark photoperiod.

The evergreen Ligustrum lucidum (glossy privet) suffers from freezing injury in northern China, where there are short growing seasons and early fall frost events. To investigate the influence of exogenous salicylic acid (SA) application on the natural cold acclimation of glossy privet, physiological and biochemical changes in glossy privet seedlings subjected to SA treatments at four concentrations (0, 150, 250, and 350 mg·L−1) were evaluated from Sept. to Dec. 2016. The optimum application concentrations were between 250 and 350 mg·L−1, which led to better freezing tolerance during natural cold acclimation. The improved freezing tolerance under exogenous SA application was associated with the accumulation of chlorophyll, proline, soluble protein, and soluble sugar, and the regulations of gibberellic acid (GA) and abscisic acid (ABA). Salicylic acid treatments started a cascade of steps for advancing the cold acclimation process of glossy privet. We suggest that exogenous SA application may be used on glossy privet grown in northern China.

Few genes have been identified in red beet. A spontaneously occurring dwarf mutant was identified in the late 1970s and again in 1994 in several breeding populations. Mutant plants are characterized by extreme dwarfing of both root and shoot. Young leaves are narrow, thin and strap-like while older leaves are thicker and deeply veined. The shoot axis forms a compressed rosette. Neither the shoot axis nor the root axis of field-grown plants exceeds 3 cm in height. Genetic analysis of F2 and backcross populations revealed the dwarf phenotype is conditioned by a single recessive gene. Several experiments were conducted to determine if the dwarf phenotype was due to a lack of gibberellic acid (GA) production. Exogenous application of GA3 at concentrations ranging from 1 to 1000 ppm on dwarf plants a) following seeding and b) during reproductive growth revealed a linear increase in plant height. Control dwarf plants receiving a water-only treatment were 18% as tall as plants receiving regular application of 1000 ppm GA3. A wild-type phenotype during reproductive growth was recoverable following regular GA3 application.

We evaluated the extent to which `Swenson Red' seeded grape (Vitis × spp.) responded to single and repeated GA3 applications to induce seedless fruit development. Field studies were conducted to test the time of pre-anthesis GA3 application (18, or 24 May or 3 June), the usefulness of postanthesis application, the optimum GA3 concentration (0, 0.075, 0.15, or 0.3 mm), and the method of application. The treatment dates that gave a high percentage of seedless berries with an acceptable berry count per cluster were 24 May with postanthesis application and 3 June pre-anthesis only. The optimum GA3 concentration was 0.15 mm applied both before and after anthesis. The most seedless berries developed when pre- and postanthesis applications were used, indicating many seedless fruit developed from flowers that would have abscised. There was no difference in percent heedlessness, number of berries per cluster, or number of seeds per berry between clusters dipped or sprayed with 0.3 mm GA3. Chemical uame used: gibberellic acid (GA3).

The aim of this study was to evaluate the effect of pre-treatments on overcoming dormancy of A. coriacea seeds. Seeds were processed and stored in polyethylene bags at temperatures of at -18°C (42% RH), 5°C (34% RH), 15°C (60% RH) and 25°C (34% RH), during 0, 30, 60, 90, 120 and 150 days. After storage, seeds were immersed in 350 mg.L−1 gibberellic acid for 144 hours. Sowing was carried out in plastic bags containing Red Latosol + Bioplant®. Moisture content, emergence percentage, emergence speed index, length and dry mass of seedlings, were evaluated. The experimental design was completely randomized in a factorial with four replications of 50 seeds each. The seed storage at 5°C and subsequent immersion in gibberellic acid was efficient to reach high percentage, emergence speed and plant growth. A. coriacea seeds showed non-deep simple morphophysiological dormancy wherein the physiological component can be overcome after the seeds are storage at 5°C for a maximum period of 53 days and subsequent immersed in exogenous GA (350 mg.L−1 for 144 hours).

Our objectives were to determine if gibberellic acid (GA3) application at color break in the fall affected the juice content, soluble solids content (SSC), titratable acid (TA), and ratio of SSC: TA of `Hamlin' orange (Citrus sinensis) fruit following moderate to severe freezes. We also wanted to know if GA3 affected the post-freeze rate of decrease in juice content, fruit and tree cold hardiness, and the amount of fruit drop following a freeze. GA3 (18 floz/acre) was applied at color break in the fall of 2002, 2003, and 2004 to `Hamlin' orange trees on Swingle citrumelo (C. sinensis × Poncirus trifoliata) rootstock planted in 1995 at Gainesville, Fla. Moderate to severe freezes occurred in all three seasons. Fruit were harvested at about 2-week intervals following freezes in each season and the internal fruit quality was determined. GA3-treated fruit generally had higher juice content compared with nontreated fruit for 8 weeks after moderate to severe freezes in all three seasons, which may be economically important to citrus processors and growers since Florida growers are paid based on fruit pounds-solids (juice content × SSC). The rate of decrease in juice content over time was similar for both treatments in seasons one and two, but was less for GA3-treated fruit than nontreated fruit in season three. In addition, SSC was equal to or slightly greater for fruit treated with GA3 than for nontreated fruit. Fruit drop rate and magnitude were also significantly less for the GA-treated compared with nontreated trees in two of three seasons. GA3 did not affect fruit, leaf, or tree cold hardiness in any season.

A method for micropropagation of Conocarpus erectus through axillary shoot proliferation is presented. Shoot tips were excised from adult donor tree and cultured for 4 weeks on Murashige and Skoog’s (MS) medium supplemented with 3 mg·L−1 gibberellic acid (GA3) to induce sprouting of shoots and formation of axillary shoots. Conocarpus erectus shoots were cultured for 6 weeks on MS medium supplemented with different concentrations and combinations of plant growth regulators (PGRs) and proliferation of the shoots was monitored. The type and concentration of cytokinins applied had a significant influence on shoot proliferation responses. Supplementation with 6-benzylaminopurine (BAP) increased the rate of shoot proliferation compared with other cytokinins. The use of BAP in combination with auxins such as indole-3-butyric acid (IBA) and naphthalene acetic acid (NAA) resulted in an increased number of shoots per explant compared with treatment with BAP alone. A combination of 2 mg·L−1 BAP and 0.5 mg·L−1 IBA produced the highest number of axillary shoots (7.8 shoots/explant). The best rooting medium was full-strength MS medium supplemented with 1 mg·L−1 IBA; this treatment yielded 80% rooting with an average of 3.5 roots per plantlet. All regenerated plantlets were successfully acclimatized to greenhouse conditions.

This study explores the effects of nanomaterials in rice seedlings using carbon 13 (13C)-labelled fullerene (C60). The experiment consisted of three groups, one CK and two nano particle groups with C60: 100 mg L−1 and 20 mg L−1. Mass spectrometry indicated higher 13C abundances in the nano particle groups compared with the CK. The 13C abundances of the 20 mg L−1 group, 100 mg L−1 group and CK were 1.0718%, 1.0715% and 1.0704%, respectively. We analyzed phytohormone concentrations in the rice at harvest time. Decreases in the concentrations of dihydrozeatin riboside (23% and 18% for the 20 mg L−1 and 100 mg L−1 group, respectively), zeatin riboside (23% and 18%, respectively), abscisic acid (11.1% and 12.7%, respectively), brassinolide (12.9% and 13.1%, respectively) and gibberellic acid 4 (12.9% and 13.1%, respectively) were observed compared with the CK. The gibberellic acid 3 concentrations in the 20 mg L−1 and 100 mg L−1 group increased by 12% and 7% compared with the CK, respectively. The methyl jasmonate concentration in the 100 mg L−1 group increased by 19.4% compared with the CK. The concentration of indole-3-acetic acid in the 100 mg L−1 group decreased by 13.5% compared with the CK. There was no change on isopentenyl adenosine concentration. This study indicates that C60 can be absorbed by rice and its effect on the growth of rice via phytohormones, including ABA, IAA, IPA, BR, GA3, GA4, DHZR, ZR and JA-ME. The results showed that, under the treatments of C60 NMs, the contents of some phytohormone in rice were decreased in comparison with CK.

Leucaena leucocephala is a tree species used for several agricultural purposes in Mediterranean region. The seeds of these species exhibit dormancy causing delayed germination. A series of experiments evaluated the effects of various treatments on the germination of leucaena leucocephela L. seeds. Germination of fresh seeds was 46% but it was improved (to about 70%) by mechanical scarification using sand paper. A germination of about 60% was obtained when dry seeds were pre-chilled at 4 ̊C for 2,3 and 4 weeks prior to germination that various storage periods of pre-chilling had no influence upon germination enhancement of seeds. Exposure of seeds to -18 ̊C inhibited germination in comparison to the control. There was no significant increase in germination percentage after cold treatment. Maximum improvement being achieved when seeds were kept dry under alternating cold/ warm temperatures for 8days at two day intervals prior to germination, since germination percentage increased to 73%. A significant promotion was recorded when seeds treated with 100 mg/l GA3 prior to germination and that pre-chilled treatment improved germination percentage compared with those un-chilled the maximum (70%) at 100 mg/l of GA3.The effect of nutrient media on seed germination was studied on MS and B5 media after being stored for one week in refrigerator (at 4°C) or in the freezer (-18°C). The germination percentage of Leucaena seeds cultured on MS medium showed a significant increase over the control for those stored one week at 4°C, when the effect of B5 medium on seed germination was found to be similar to the control (50%) for seeds stored one week at 4°C. These results demonstrate that alternating temperatures (cold/warm) provide faster and highest germination percentage and could be secured at low cost which would be adequate to large scale treatment of Leucaena leucocephala seeds.

Harvest bunch rot of wine grape, caused primarily by Botrytis cinerea, is a perennial problem limiting the productivity of eastern vineyards, especially on cultivars with compact clusters. The aim of the present study was to evaluate the effectiveness of gibberellic acid (GA) sprays at reducing the compactness of Chardonnay and Vignoles clusters and minimizing bunch rot. Applications of GA reduced the number of berries per centimeter and the incidence and severity of bunch rots in Vignoles and, to a lesser extent, in Chardonnay over three consecutive years; however, the magnitude of GA effects often depended on the timing and rate of application. Bloom GA applications were more effective (P < 0.001) at reducing compactness and bunch rots than prebloom applications. Significantly, negative effects of GA applications on yield were negligible based on data from 4 years of trials on single vines and 2 years of data on 24-vine plots of Vignoles, provided the rates did not exceed 25 ppm. Regression analysis showed that berries per centimeter accounted for between 89 and 94% of variation in the incidence of Botrytis rot on Vignoles. On Chardonnay, compactness accounted for 53% of the variation in incidence, and the estimated compactness level at which no bunch rot would occur was 4.40 ± 1.05 (mean ± standard error) berries per centimeter. The relationship between cluster compactness and spray coverage of berries was also investigated in two separate experiments. Spray coverage of individual berries decreased linearly as cluster compactness increased within the range tested (3 to 18 berries per centimeter). Cluster compactness accounted for two-thirds of the variation in individual berry coverage, and coverage was reduced by 40 to 50% for clusters with about 18 berries per centimeter. These results strongly support the use of GA in integrated management of bunch rot on Vignoles and Chardonnay in eastern U.S. vineyards.

Nanopriming has been shown to significantly improve seed germination and seedling vigor in several agricultural crops. However, this approach has not been applied to native upland boreal forest species with complex seed dormancy to improve propagation. Herein, we demonstrate the effectiveness of carbon nanoparticles functionalized with carboxylic acids in resolving seed dormancy and improved the propagation of two native upland boreal forest species. Seed priming with carbon nanoparticles functionalized with carboxylic acids followed by stratification were observed to be the most effective in improving germination to 90% in green alder (Alnus viridis L.) compared to 60% in the control. Conversely, a combination of carbon nanoparticles (CNPs), especially multiwall carbon nanoparticles functionalized with carboxylic acid (MWCNT–COOH), cold stratification, mechanical scarification and hormonal priming (gibberellic acid) was effective for buffaloberry seeds (Shepherdia canadensis L.). Both concentrations (20 µg and 40 µg) of MWCNT–COOH had a higher percent germination (90%) compared to all other treatments. Furthermore, we observed the improvement in germination, seedling vigor and resolution of both embryo and seed coat dormancy in upland boreal forest species appears to be associated with the remodeling of C18:3 enriched fatty acids in the following seed membrane lipid molecular species: PC18:1/18:3, PG16:1/18:3, PE18:3/18:2, and digalactosyldiacylglycerol (DGDG18:3/18:3). These findings suggest that nanopriming may be a useful approach to resolve seed dormancy issues and improve the seed germination in non-resource upland boreal forest species ideally suited for forest reclamation following resource mining.

Endogenous hormones can improve plant resistance and regulate growth and development. To obtain the basis of chemical control technology for improving Sequoia sempervirens resistance in Xuzhou, China, the current study probed the dynamic changes of endogenous hormones in terminal buds from different crown positions in S. sempervirens. Enzyme-linked immunosorbent assay (ELISA) was used to measure changes in the contents of endogenous hormones in terminal buds from the upper, middle, and lower lateral branches. The results were as follows: Indole acetic acid (IAA) in all terminal positions had a similar change trend of “rise–drop–rise.” Gibberellic acid (GA) in the upper and middle terminal buds showed similar trends of “drop–rise,” but GA in the lower lateral branches presented a “rise–drop” trend. Zeatin–riboside (ZR) in all terminal positions had similar change trends of “drop–rise.” Abscisic acid (ABA) in all terminal positions had similar change trends of “drop–rise–drop.” the trend of (IAA + GA + ZR)/ABA in all terminal positions was the same as that of IAA. Our results confirmed that, in autumn, the high content and ratio of stimulatory endogenous hormones in the terminal bud of S. sempervirens induced the terminal bud cells to continue to divide and grow, and the new branches could not be fully lignified and deeply dormant before the onset of low temperatures in winter, which led to a decrease in cold resistance and even the death of the terminal buds.

Propagation of Winecups [Callirhoe involucrata (Torrey & A. Gray)] for use as a landscape ornamental has been impeded by a lack of understanding of the seed dormancy and a practical method for overcoming it. As with many members of the Malvaceae family, C. involucrata produces hard seed. In the populations tested, it accounted for 90% of an average sample. Impermeability, however, is not the only limiting factor to germination. Three disparate populations of seed, representing two different collection years have been investigated using moist pre-chilling, boiling water, leaching, gibberellic acid, hydrogen peroxide and mechanical and chemical scarification methods. Scarifying in concentrated sulfuric acid stimulates germination of some seed fractions and causes embryonic damage in others, suggesting variation in seed coat thickness. Similar results were obtained using a pressurized air-scarifier; the hard seed coat of some seed fractions were precisely scarified while others were physically damaged using the same psi/time treatment. Placing seed in boiling water increases germination from 4%, 7%, and 18 % to 23%, 25%, and 77% in the three populations, respectively. Leaching for 24/48 h in cold (18 °C) aerated water or for 24 h in warm (40 °C) aerated water showed only a minor increase over the control. Pre-chilling at 5 °C for 30, 60, and 90 days showed no improvement over the control. Gibberellic acid-soaked blotters improved germination at 400 ppm to 20%, 10%, and 41%; at 500 ppm germination was reduced. Soaking seed for 24 h in a 3% concentration of hydrogen peroxide did not effect germination; at a 30% concentration germination was reduced. The considerable variation in seed dormancy expression may be a function of differences in environmental factors during development or seed age.

<p class="1Body">A comparison study between the application of gibberellic acid (GA3) and <em>Saccharomyces cerevisiae</em> as a biostimulant on the growth and molecular structures of Eggplant (<em>Solanum melongena</em> L.) has been carried out through a pot experiment. Growth of <em>Solanum melongena</em> L. increased with exogenous application of GA3 followed by yeast. Chlorophyll contents of plant were enhanced with yeast treatment compared with GA3 application and control. Activitiy of antioxidant enzymes, catalase and peroxidase was increased with increasing concentration of GA3 and <em>S. cerevisiae</em> application particularly with using GA3. HPLC analysis showed the highest concentration of salicylic acid in plant treated with GA3 (104.20 mg) followed by <em>S. cerevisiae</em> (70.00 mg) application compared with the untreated plant (57.86 mg). Six common polypeptide bands were observed in treated and untreated <em>S. melongena</em> plants, their molecular weights were 16, 17, 34, 90, 120 and 150 KDa. While the untreated <em>S. melongena</em> plant is characterized by the presence of 8 polypeptide bands, their molecular weights were 19, 24, 32, 33, 36, 50, 109 and 133 KDa. Yeast treatment increased the number of protein bands to 12 instead of 8 in the control plant with molecular weights 18, 125, 74, 69, 62, 31, 30, 27, 25, 23, 20 and 18 KDa. Three polypeptide bands with molecular weights 25, 72 and 125 KDa were detected in <em>S. cerevisiae</em> and GA3 treated plants. PCR analysis showed that total of 16 amplified fragments was visualized in the tested samples. Eight fragments with different molecular weights, four of them are monomorphic bands while the others are polymorphic unique bands. Plant sample sprayed with yeast showed 5 fragments range in molecular weight between 426 to 1766 bp. Only one of these fragments was unique polymorphic fragment. Four monomorphic fragments range in molecular weight from 426 to 1213 bp were showed up in plant sample sprayed with gibberellic acid.</p>

The investigations were conducted on the germinating embryos and the whole caryopses of <em>Triticale</em>. During preimbibition and 24 hours germination caryopses were treated with abscisic acid (ABA), which produced 63% inhibition of embryo growth. Gibberellin-A₃ (GA₃) reversed the ABA effect in 18%, while zeatin in 22%. The clear synergic reaction was observed (36%) when both stimulators acted together. There was no significant effect of ABA, ABA and GA₃, as well as ABA and zeatin on the synthesis of polyribosomal RNA in the initial period of germination of excised embryos. However, during 24 hours germination of whole caryopses ABA caused a twofold decrease in ³H-uridine incorporation into the total fraction of embryonic ribosomes. While the incorporation of ¹⁴C-aminoacid mixture into ribosomal proteins was even three-fold lower. Effect of GA₃ and zeatin on breaking of the ABA-induced "dormancy" was studied. It was confirmed that the higher polyribosome contribution to the sum total of ribosomes the more intensive synthesis of ribosomal proteins. No higher ³H-uridine incorporation into polyribosomal fraction was observed. From the results it may be inferred that in the initial period of germination of <em>Triticale</em> caryopses regulation of protein biosynthesis occurs rather at the translation than transcription level.

Abstract Tubers of Zantedeschia elliottiana (Watson) Engl. and the hybrid Z. ‘Pink Satin’, a Z. rehmannii Engl.-like selection, were stored at 5°C. Over a 3-month period they were transferred to incubators at 12°, 18°, or 24° for 2, 4, 6, 8, or 12 weeks of holding. One-third of these tubers were planted in moist media during this time; the remaining tubers were stored dry and on removal were sprayed with either gibberellic acid (GA3) at 50 mg·liter−1 or distilled water before planting and transfer to a greenhouse. The proportion of flowering of dry-stored tubers of Z. elliottiana was reduced by prolonged storage at 5°. Subsequent storage at 12° did not reduce this proportion, but, at 18° and 24° flowering was reduced further. Tubers of Z. ‘Pink Satin’ were less sensitive to the duration of dry storage at 5°, but increasing time of storage at all subsequent temperatures caused a progressive decrease in the proportion of tubers that flowered. The proportion of moist-stored tubers of both selections that flowered was greater than that for tubers stored dry for an equivalent time. A preplant treatment with GA3 enabled almost total compensation for reduced flowering except after the longest period of storage.

A field study was conducted during the Rabi season of 2009-2010 in the research field of Bangladesh Council of Scientific and Industrial Research (BCSIR), Dhaka. Six levels of GA3, viz. 0, 30, 50, 70, 90 and 110 ppm were sprayed at 18 days after sowing (DAS). GA3 treatments significantly increased plant height than the control plants. GA3 with 30 to 90 ppm significantly increased number of branches and leaves, leaf area, leaf area index (LAI), leaf dry matter and total dry matter at different growth stages. GA3 at 30 to 70 ppm gradually increased crop growth rate (CGR), net assimilation rate (NAR) and relative growth rate (RGR) and declined advanced growth stages. Number of dry pods /plant, number of seeds /pod, 1000 seed weight, fresh fodder, fresh pod, dry seed yield and harvest index also significantly increased. Positive significant correlations were found among growth parameters and as well as yield contributing characters. Asiat. Soc. Bangladesh, Sci. 43(1): 49-60, June 2017

Kohlrabi (Brassica oleracea var. gongylodes), with its edible stem tuber formed at the base of the plant stem, presents a valuable source of nutrients. The potential effects of plant growth regulators (PGRs), as well as various concentrations of different sugars on the in vitro development of kohlrabi were studied. Ten-day-old kohlrabi seedlings were cultivated in vitro for 5 weeks at 18?2?C on half-strength MS media containing different concentrations of carbon source such as sucrose, fructose, glucose, xylose and mannitol, combined with or without specific plant growth regulators (N6-benzyladenine (BA), gibberellic acid (GA3), 2,3,5-triiodobenzoic acid (TIBA)). Results showed no tuber formation in all treatments, but growth and development of treated kohlrabi seedlings was significantly affected in a distinctive manner, with a variety of morphological traits being altered in comparison to matching controls.

Tubers of Sandersonia aurantiaca Hook. were soaked in 1000 mg·L-1 GA3, 20 mg·L-1 uniconazole, 200 mg·L-1 benzyladenine, or water for 2 hours and then sprouted at 12, 18, or 24 °C. The effects of these treatments on flower stem quality were then determined at forcing temperatures of 18, 24, or 30 °C. Stem length increased with sprouting temperature only at a forcing temperature of 18 °C. Floret numbers increased with sprouting temperature at all forcing temperatures, but the effect was greatest at the 18 °C forcing temperature. The 12 °C sprouting treatment reduced floret numbers at all forcing temperatures. Soaking tubers in GA3 increased stem length but drastically reduced floret numbers, while soaking in uniconazole reduced stem length but had no significant effect on floret numbers. Soaking in BA strongly promoted branching, which resulted in large increases (>30%) in floret numbers per stem with little change in stem length. Of the three growth regulators, only BA was effective in improving cut flower stem quality. Chemical names used: gibberellic acid (GA3); (E)-(+)-(S)-(4-chlorophenyl)-4,4-dimethyl-2-(1,2,4-triazol-1-yl)-pent-1-ene-3 -ol (uniconazole); N6-benzylamino purine (benzyladenine; BA).

Black-spot symptoms, caused by Alternaria alternata, developed in persimmon fruits during prolonged storage at -1°C. A preharvest treatment with gibberellic acid (GA3) extended the storage life of the fruit by delaying both black-spot development and fruit softening. Conversely, treatment of persimmon fruits with paclobutrazol (PBZ), an inhibitor of gibberellin (GA) synthesis, enhanced black-spot development and fruit softening during storage. Production of endo-1,4-β-glucanase (EC 3.2.1.4, EG) by A. alternata in culture and in the presence of cell walls from PBZ-treated fruits as the carbon source, was enhanced by 150% over production in the presence of cell walls from control fruits, whereas endoglucanase (EG) production in the presence of cell walls from GA3-treated fruits was reduced by 49% relative to controls. To determine the importance of EG in symptom development, A. alternata EG was purified from a culture-inducing medium. It had a molecular mass of 41 kDa, its optimal pH and temperature for activity were 5.5 and 47°C, respectively, and the pI was 4.3. Its Km and Vmax were 0.43 mg ml-1 and 18 μmol reducing groups minute per milligrams of protein, respectively. The internal sequence of a 21-mer amino acid peptide from the purified EG showed 62% similarity and 38% identity to the EG-1 of Trichoderma reesei and of T. longibrachiatum. Purified EG induced black-spot symptoms on the fruit, similar to those caused by A. alternata, whereas boiled enzyme caused only pricking signs. Our results suggest that the black-spot symptoms caused by A. alternata, in persimmon, are related to the ability of the fungus to produce EG in developing lesions.

Somatic embryos (SEs) can play important roles in genetic manipulation and breeding. They can be used as targets for induced mutagenesis, as material for cryopreservation and germplasm conservation, and for transformation or gene editing in support of plant improvement and proof of gene function. However, germination rates of walnut (Juglans regia) SEs are low, and the genetic stability of plantlets regenerated from them has not been explored. Here, we studied first the effects of gibberellic acid (GA3) and low temperature storage (LTS) on germination of walnut somatic embryos. Second, we assessed the genetic fidelity of plantlets regenerated from these SEs by comparing them to each other and to their cultivar of origin. Results showed that GA3 and LTS increased the walnut SE germination rate. The best rate was observed when SEs were subjected to LTS for 60 d followed by culture on a medium with either 1 or 3 mg·L−1 GA3 (56.6% and 46.6% germination respectively). Genetic stability was evaluated, using flow cytometry and 15 sets of ISSR primers. Flow cytometry indicated that all samples (i.e., regenerated and parental counterpart) showed the same peak. Amplified fragments of inter simple sequence repeats (ISSR) primers ranged in size from ≈200 to 1800 bp. All ISSR profiles of regenerants were monomorphic. Results did not show any genetic differences among plantlets regenerated from SEs or from their parental counterpart. Due to this apparent genetic stability, walnut SEs can be useful for genetic transformation and germplasm conservation.

Mildew resistance locus O (Mlo) gene was first found in barley as a powdery mildew susceptibility gene, and recessive mlo alleles confer durable resistance to barley powdery mildew. To identify candidate Mlo susceptibility genes in rubber tree, HbMlo12 was cloned from rubber tree clone CATAS7-33-97, which is susceptible to powdery mildew. Protein architecture analysis showed that HbMlo12 was a typical Mlo protein with seven transmembrane domains. Protein blast search in the Arabidopsis thaliana proteome database showed that HbMlo12 shared the highest similarity with AtMlo12, with 63% sequence identity. Furthermore, HbMlo12 together with the dicot powdery mildew susceptible Mlo proteins (including AtMlo2, AtMlo6, AtMlo12, tomato SlMlo1, pepper CaMlo2, pea PsMlo1, etc.) were grouped into clade V. Subcellular localization analysis in tobacco epidermal cells revealed that HbMlo12 was localized to the endoplasmic reticulum membrane. HbMlo12 was preferentially expressed in the flower and leaf of rubber tree. Moreover, its expression was significantly upregulated in response to powdery mildew inoculation. Application of exogenous ethephon caused a distinct increase in HbMlo12 expression. Additionally, HbMlo12 transcript was quickly induced by spraying salicylic acid and gibberellic acid and reached the maximum at 0.5 h after treatments. By contrast, HbMlo12 expression was downregulated by methyl jasmonate, abscisic acid, and drought stress treatments. There was no significant change in HbMlo12 expression after indole-3-acetic acid, H2O2, and wounding stimuli. Taken together, these results suggested that HbMlo12 might be a candidate Mlo gene conferring susceptibility to powdery mildew in rubber tree. The results of this study are vital in understanding Mlo gene evolution and developing new rubber tree varieties with powdery mildew resistance using reverse genetics.

Individual flower clusters of `Tifblue' rabbiteye blueberry (Vaccinium ashei Reade) were treated with 300 ppm GA at several flower bud stages to determine the activity of the growth regulator in promoting fruit set. Applications were made one time only at a specified stage of flower development, or once followed by a second application. A single application of GA when flower buds had elongated but corollas had not expanded (stage 5) led to the largest increase in fruit set. Two applications of GA, 10 to 18 days apart, increased fruit set compared with a single application at flower developmental stages other than stage 5. Fruit set promoted by a single spray of GA imposed on fully expanded corollas (stage 6) decreased with increasing number of chill hours (350, 520, 760, or 1150). Chemical names used: gibberellic acid (GA).

Seed germination is one of the most important stages during plant life cycle, and DOG1 (Delay of germination1) plays a pivotal regulatory role in seed dormancy and germination. In this study, we have identified the DOG1-Like (DOG1L) family in soybean (Glycine max), a staple oil crop worldwide, and investigated their chromosomal distribution, structure and expression patterns. The results showed that the GmDOG1L family is composed of 40 members, which can be divided into six subgroups, according to their evolutionary relationship with other known DOG1-Like genes. These GmDOG1Ls are distributed on 18 of 20 chromosomes in the soybean genome and the number of exons for all the 40 GmDOG1Ls varied greatly. Members of the different subgroups possess a similar motif structure composition. qRT-PCR assay showed that the expression patterns of different GmDOG1Ls were significantly altered in various tissues, and some GmDOG1Ls expressed primarily in soybean seeds. Gibberellic acid (GA) remarkably inhibited the expression of most of GmDOG1Ls, whereas Abscisic acid (ABA) inhibited some of the GmDOG1Ls expression while promoting others. It is speculated that some GmDOG1Ls regulate seed dormancy and germination by directly or indirectly relating to ABA and GA pathways, with complex interaction networks. This study provides an important theoretical basis for further investigation about the regulatory roles of GmDOG1L family on soybean seed germination.

Ovules of babaco [Carica pentagona (Heilborn) Badillo], 23 to 140 days old, were cultured to initiate regenerative callus. Callus developed from the integuments and possibly from the nucellus. Ovules of greater length and age produced more calli on White's medium or medium with half-strength MS salts than on full-strength MS. Ovules >60 days old that were chilled for 24 hours produced significantly more callus than fresh ovules <60 days old. Ovular calli of summer and fall fruits (73 to 90 days old) grown at 23 ± 2C under cool-white fluorescent lamps (16- or 18-hour photoperiod, 12 or 16 μmol·s-1·m-2) developed green areas that subsequently produced nodular structures. Nodular structures produced proembryonal structures that developed into mature somatic embryos when transferred to media containing either GA3 (0.1 mg·liter-1) plus activated charcoal (2.0 g·liter-1) or casein hydrolysate (200 mg·liter-1) plus IAA (0.5 mg·liter-1). Somatic embryos converted into plantlets when transferred to embryo conversion medium. Chemical names used: 1-H -indole-3-acetic acid (IAA); gibberellic acid (GA3).

Gladiolus grandiflorus is known and grown for its high profit and excellent cut flower. To compete with other growers and to meet the consumer demand the grower should adopt new techniques and apply effective chemicals to the plant precisely which in result gives good quality flowers. For this an experiment was carried out on Gladiolus grandiflorus cv. Rose supreme in experimental area of department of horticulture, Bahauddin Zakariya University, Multan. There were 6 treatments and 3 replications and the corms were planted in pots. Each treatment in replications is replicated four times to get best results. The sowing was done on 3rd December 2018 and the first application of chemicals was applied on 15/02/2019. The total number of applications was 6 and each application was applied by foliar application after one week interval. The chemicals were silicon and gibberellic acid. Silicon is applied as T0 (0g), T1 (1g), T2 (2g), T3 (3g), T4 (4g) and T5 (5g) while gibberellic acid has a fixed dose of 200ppm in each treatment. The best results related to vegetative and floral parameters were observed in T4 treatment plants which showed best result and an increase in stalk length, spike length, diameter of floret, diameter of spike, number of leaves per plant, vase life, number of florets per spike, fresh weight of complete flower stalk and plant height.KeywordsGA3, silicon, rose supremeINTRODUCTIONGladiolus is commonly known and grown for its high aesthetic and economical value, especially in Pakistan economy. It is placed second important cut flower in Pakistan while fourth most important cut flower in the world. The cultivated area of gladiolus is only 970 acre and is too small as compared to rose which is 9200 acre and tuberose which is 2787 acre (Khan, 2005). Gladiolus belongs to Iridaceae family; holds about 260 species but many of them are wild. Native to Africa but some species are also from Mediterranean, South Africa and from Europe (Dole and Wilkins, 1999). Progressive farmers in Pakistan are now converting to floriculture industry instead of growing traditional crops, for this rose, gladiolus, tuberose and carnation are the best flowers that give maximum profit in low time period. The total cultivated area of gladiolus in Punjab is more than 450 acres. Plant growth regulators are responsible especially for the physical attributes of a plant in an effective way. Treating plants with plant growth regulators is very mandatory to enhance the growth and yield of plants (Nuvale et al., 2010). Different doses of GA3 can affect significantly on the vegetative as well as reproductive growth of gladiolus (Umrao et al., 2007). GA3 can increase the height, number of florets and can initiate early sprouting of flowers (Taiz and Zeiger, 2002). Silicon is the 2nd most available element on Earth’s crust; about 32 percent silicon is present in soil by weight. 1% to 10% silicon is present in plant dry matter. The available form of silicon that plant can easily uptake is called as Mono salicylic acid Si(OH)4. Silicon is mostly required during vegetative as well as reproductive growth of the plant to attain healthy and maximum yield from plant (Savant et al., 1997). Farmers now a days do not have proper knowledge of cultivating flowers that is the reason they apply extra chemicals to get maximum yield but cannot achieve it because the amount and type of chemical they are applying are used for traditional crops, ornamentals and flowers have their own need of different chemicals for this, the research is done to describe the role of chemicals on gladiolus to attain maximum yield with high quality flowers.MATERIALS AND METHODSThe research was carried out at experimental area of Department of Horticulture, Bahauddin Zakariya University Multan, Pakistan. The research was done to get and to elaborate the outcome of foliar use of GA3 and Silicon on growth, yield and flowering of Gladiolus grandiflorus cv. Rose supreme in pots. Soil samples were taken from various pots and then collected to check the soil properties i.e. its acid: base ratio, Electrical conductivity, form and the amount the nutrients present in the soil. The combination of soil media used in the research was 1:1 (Silt: Leaf manure) and the pots were placed according to the statistical design which was Randomized Complete Block Design (RCBD). The corms of Gladiolus grandiflorus cv. Rose supreme was imported from Netherlands. The treatments were applied as 200 ppm of Gibberellic acid (GA3) and 1, 2, 3, 4, 5 g/L of silicon as sodium meta-silicate. The treatments were applied by foliar application with different combination in a Randomized complete block design (RCBD) which is as follows in table 1.Data collection: Following were the some parameters in table 2 taken to elaborate the outcome of foliar use of GA3 and silicon on the growth, flowering and yield of Gladiolus grandiflorus cv. Rose supreme.On 3rd December, corm sowing was done. One corm was in each pot. There were total 6 treatments one was control which has only 200 ppm GA3 while others have different silicon doses as well as has fixed dose of GA3. Each treatment was divided into 4 pots thus total No. of pots were (6 × 3 × 4) = 72 having three replications. GA3 and silicon was applied by foliar application with one week interval. The first foliar application was done before stick formation and the date was 15/02/2019, while the last application was done on 22/03/2019. The total number of applications was six and was applied through foliar imple-mentation of chemicals. The cultural practices, integrated pest management and fertilizer application were done thoroughly on each replication with equal amount of dose.RESULT AND DISCUSSIONStalk length (cm): Table 3 showed the best effect of silicon and Gibberellic acid as T4 which showed maximum stalk length T4 (80.543) after that T1 (78.833), T0 (76.667), T3 (73.417) and T5 (73.167) while T2 (72.833) showed minimum stalk length. The stalk length was taken in cm. The length of stalk was approximately similar to each other by the application of silicon and Gibberellic acid. On the other hand table 4 showed the ANOVA for stalk length of gladiolus. Maximum stalk length will give maximum profit to flower growers that’s why it is important to choose efficient chemicals that enhance the flower growth as well as the accurate dose of chemical is also important to get maximum results. Increase in stalk length was also reported in anthurium through foliar allocation of GA3 (Dhaduk et al., 2007).Spike length (cm): The best results were shown in different concentrations among those T4 concentration showed best result and then T1, T3, T0, T2 and T5 respectively. The results of the chemicals on spike length are shown in table 5. Different concentrations imparts favorable impact on spike length and increase their size as T4 (33.350), T1 (31.750), T3 (29.707), T0 (28.833), T2 (28.267) and T5 (27.303). More spike length increased the profit ratio of flower grower and meets the cons-umer demand more precisely. Good spike length is an important constituent to increase the quality of flower. The statistical analysis i.e. ANOVA for spike length of gladiolus is shown in table 6. To increase the quality of flower it is mand-atory to choose best and most effective chemical and applied with the recommended dose which in result gives maximum quality flower. It was reported that spike length and stalk length can be increased via foliar allocation of GA3 on anthurium (Dhaduk et al., 2007).Diameter of spike (cm): The best results were shown in different concentrations among those T4 concentration showed best result and then T1, T3, T2, T0 and T5 respectively. Different concentrations imparts favorable impact on spike length and increase their size as T4 (0.5990), T1 (0.5990), T3 (0.5887), T2 (0.5867), T0 (0.5700) and T5 (0.5443) as shown in table 7. In table 8 ANOVA for diameter of spike of gladiolus showed significant results. More diameter of spike increased the profit ratio of flower grower and meets the consumer demand more precisely. Good diameter of spike is an important constituent to increase the quality of flower. To increase the quality of flower it is mandatory to choose best and most effective chemical and applied with the recommended dose which in result gives maximum quality flower.Diameter of floret (cm): The best results were shown in different concentrations among those T4 concentration showed best result and then T1, T2, T3, T5 and T0 respectively. Different concentrations imparts favorable impact on diameter of floret and increase their size as T4 (0.6890), T1 (0.6817), T2 (0.6700), T3 (0.6600), T5 (0.6300) and T0 (0.6100) as shown in table 9. Significant results were seen in ANOVA table 10.Quality of flower i.e. its size and color is very important to get maximum profit and to sustain in a competitive market. To achieve best flower size different chemicals and plant growth regulators are applied which have positive effects on the growth and nourishment of flower. Silicon and Gibberellic acid showed their best result at the concentrations as 200ppm Gibberellic acid and 4g of silicon.Number of leaves per plant: Table 11 showed the best results in different concentrations among those T4 concentrations showed best result and then T1, T2, T3, T0 and T5 respectively. Different concentrations imparts favorable impact on number of leaves per plant and increase their size as T4 (8.9167), T1 (8.8333), T2 (8.6667), T3 (8.6333), T0 (8.4667) and T5 (7.5100). Number of leaves in each treatment from T0-T4 was approximately same but in T5 the number of leaves decreased. Number of leaves in any plant was most important because they are responsible for the photosynthesis which in result provides energy to the plant body to grow well. Table 12 showed statistical approach of number of leaves per plant. More number of plants will cause more photosynthesis and in result the plant grow well with good quality flowers for the consumer thus gives maximum profit to the flower grower. It is reported in different experiments that Gibberellic acid is responsible to increase the number of leaves in chrysanthemum and other cut flowers (Naira et al., 2003).Vase life (days): The best results were shown in different concentrations among those T4 concentration showed best result and then T5, T2, T0, T1 and T3 respectively. Different concentrations imparts favourable impact on vase life and increase as T4 (10.580), T5 (8.777), T2 (8.763), T0 (8.750), T1 (8.583) and T3 (8.5800). Table 13 and table 14 showed the significant results. Concentration showed best result and then T1, T2, T3, T0 and T5 respectively. Different concentrations imparts favourable impact on days to spike emergence and the results are as T5 (122.40), T0 (115.83), T3 (114.92), T2 (114.58), T1 (113.83) and T4 (112.33). By the application of silicon and Gibberellic acid the days to spike emergence decrease significantly in each treatment while the best and early results were shown in T4 and the dose was 200ppm Gibberellic acid along with 4g of silicon. Table 15 showed different treatments and their result while table 16 showed significant results of days to spike emergence. The flower grower can get maximum profit by introducing its flowers earlier than other growers in the market, thus less competition will give more profit. It was reported that Gibberellic acid is responsible to maximum spike length and it is observed that minimum number of days required for spike emergence when Gibberellic acid is sprayed on plants (Devadanam et al., 2007).Number of florets per spike: The best results were shown in different concentrations among those T4 concentration showed best result and then T1, T3, T2, T0 and T5 respectively. The results were significantly described in table 17 and table 18. Different concentrations imparts favorable impact on number of florets per spike and the results are as T4 (10.583), T1 (9.660), T3 (9.333), T2 (9.250), T0 (8.550) and T5 (8.167). More number of florets on a single flower stalk will give more profit because it met the demand of consumer. Consumer will pay more to get more flowers on a single flower stalk. A significant increase in number of florets per spike was noted. An increase in number of flowers was reported on some flowering plants by the foliar application of gibberellic acid (Kumar et al., 2003).Fresh weight of complete flower stalk (g): The best results were shown in different concentrations among those T4 concentration showed best result and then T1, T3, T2, T0 and T5 respectively. The results were significantly described in table 19 and table 20. Different concentrations imparts favor-able impact on weight of newly harvested whole inflorescence stalk and results are as T4 (39.000), T1 (34.750), T3 (31.040), T2 (30.833), T0 (29.200) and T5 (25.320). More fresh weight of flower stalk is considered to be a good indicator for good quality flower which in result give consumer mental satisfaction as well as more profit to flower grower. Fresh weight of anthurium flower increase by the application of gibberellic acid as well as the increase the flower yield to some extent (Kumar et al., 2003). It was reported in chrysanthemum that an increase in fresh weight, dry weight and size of flower was observed significantly.Dry weight of complete flower stalk (g): Table 21 showed the best results in different concentrations among those T5 concentration showed best result and then T4, T0, T1, T2 and T3 respectively, while table 22 showed ANOVA for dry weight of complete flower stalk. Different concentrations imparts favourable impact on dry weighing of whole inflorescence stalk and the results are as T5 (13.423), T4 (13.363), T0 (13.313), T1 (13.280), T2 (13.160) and T3 (12.420). Dry weight of complete flower stalk of all treatments was approximately same. There is a very minute difference among them. It was reported in chrysanthemum that an increase in fresh weight, dry weight and size of flower was observed significantly (Nagarjuna et al., 1983).Plant height (cm): The best results were shown in different concentrations among those T4 concentration showed best result and then T1, T0, T3, T2 and T5 respectively. The results were significantly described in table 23 and table 24. Different concentrations imparts favorable impact on plant height and the results are as T4 (65.350), T1 (64.070), T0 (61.340), T3 (58.383), T2 (57.633) and T5 (57.513). Plant height is one of the most important parts of any plant. Consumers like the flowers which have more height because more flower height will increase the number of floret per spike. 4g silicon along with 200ppm of Gibberellic acid is recommended to increase the plant height effectively. An increase in plant height, number of leaves and branches was reported by the foliar application on Gibberellic acid on chrysanthemum and on other cut flowers (Kumar et al., 2003; Naira et al., 2003).ConclusionThe research was done in research area of Horticulture department, Bahauddin Zakariya University Multan. Randomized complete block design (RCBD) was the model on which the experiment was laid out. Total number of treatments were 6 which are as T0 (200ppm GA3), T1 (200ppm GA3+ 1g Silicon), T2 (200ppm GA3+ 2g Silicon), T3 (200ppm GA3+ 3g Silicon), T4 (200ppm GA3+ 4g Silicon) and T5 (200ppm GA3+ 5g Silicon). The best results were observed in T4 plants which has maximum effect of silicon as well as gibberellic acid. In most parameters T5 showed repellent effects due to high amount of silicon dose. CONFLICT OF INTERESTThe Author has no conflict of InterestREFERENCES: Devadanam, A., B. Shinde, P. Sable and S. Vedpathak, 2007. Effect of foliar spray of plant growth regulators on flowering and vase life of tuberose (Polianthes tuberosa L.). Journal of Soils Crops, 17(1): 86-88.Dhaduk, B., S. Kumari, A. Singh and J. Desai, 2007. Response of gibberellic acid on growth and flowering attributes in anthurium (Anthurium andreanum Lind.). Journal of Ornamental Horticulture, 10(3): 187-189.Dole, J. M. and H. F. Wilkins, 1999. Floriculture: principles and species. Prentice Hall, Upper Saddle River, U.S.A. pp. 578-581.Khan, M., 2005. Development of commercial floriculture in Asia and the pacific-issues, challenges and opportunities. In: The national seminar on streamlining: Production and export of cut-flowers and house plants, march 2nd to 4th, 2005, Islamabad, Pakistan. HFP.Kumar, P., S. Raghava and R. 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Presowing treatments and temperature regimes were tested to improve germination of Alstroemeria hybrids 3 to 12 months following harvest. In addition, seeds from 20 intraspecific F1 hybrids of five selections were also tested 3 to 7 or 8 to 12 weeks following harvest. Seeds were pretreated by chipping the seedcoat above the embryo, general abrasion of the entire seedcoat, or soaking 12 hours in distilled water, GA, (0.029, 0.29, 2.9 mm), or KNO3 (0.5 and 1.0 m). Pretreatments were evaluated under three environmental regimes: 8 weeks at a constant 18-25C (warm), 4 weeks at 18-25C followed by 4 weeks at 7C (warm-cold), or 4 weeks at 7C followed by 4 weeks at 18-25C (cold-warm). There was an interaction between pretreatment and environmental regime for percent germination. Germination percentages for the water soak and GA, at 0.29 or 2.9 mm were significantly higher than for the other pretreatments, but were not significantly different from one another. The warm-cold environment yielded higher germination percentages than the other environments. The time to germination was longest for the cold-warm regime. This response depended on the genotype and the age of the seed. Chemical name used: gibberellic acid (GA3).

Dormancy delays the germination of seeds in two species of the primitive angiosperm genus Hibbertia (H. cuneiformis and H. huegelii, family Dilleniaceae). After seed coat removal, germination increased in 18-month-old seeds of H. cuneiformis and 6- to 8-month-old seeds of H. huegelii. Hence, seeds of the two species exhibit seed coat dormancy. The removal of the seed coat may stimulate germination, as the result of increased water uptake, and/or the removal of mechanical and chemical inhibition. However, the occurrence of imbibitional injury and a reduced percentage of vigorous seedlings in decoated seeds suggest that embryo dormancy, as a second type of dormancy, impedes germination in H. cuneiformis. Embryo dormancy also delays the germination of seeds of H. huegelii, since a high percentage of seeds did not germinate after removal of the seed coat. Embryo dormancy appears to vary among individual seeds and between species. The germination experiments suggest a high percentage of non-dormant and weakly dormant embryos for 18-month-old seeds of H. cuneiformis. By contrast, many seeds of H. huegelii appear to contain deeply dormant embryos. In H. cuneiformis, the depth of the seed dormancy varied with the age of the seeds. Freshly harvested seeds did not germinate for 3 months. Treatment with gibberellic acid (GA3) (120 mg L-1) significantly enhanced germination of freshly harvested and 18-month-old, intact seeds of H. cuneiformis and the germination of decoated 18-month-old seeds of H. huegelii. The plant hormones kinetin and abscisic acid did not affect the final germination percentage in 18-month-old seeds of H. cuneiformis. For H. huegelii, germination was reduced in decoated seeds and seeds with cracked coats exposed to an 8 h day: 16 h night diurnal cycle compared with complete darkness.

Aquilegia ×hybrida `Bluebird' and `Robin', grown as greenhouse pot plants, initiated flower buds before cold exposure (4.5C) under supplemental high-pressure sodium lamps in mid-December, 5.5 months from sowing. Low temperature was the primary environmental factor that affected floral development in `Bluebird'. As the length of the cold exposure increased, the time between appearance of visible buds, anthesis, and petal shattering decreased, as did inflorescence number and total flower number per plant. Gibberellic acid (GA3) at 100 or 200 mg·liter-1 accelerated the appearance of visible buds during forcing in treatments without cold exposure. Soil drench applications of GA3 2 weeks before cold treatment accelerated floral development more than GA3 applied after cold exposure. Inflorescence number and total flower number per plant were reduced by 4 or 8 weeks but not by 2 weeks of exposure to cold. The developmental rate of “Robin', i.e., appearance of visible buds and anthesis, was quicker in plants with 18 to 20 leaves than in those with 12 to 14 leaves.

Commercialisation of many Australian everlasting daisy (Asteraceae) species islimited by poor germination, due in part to dormancy. This study examined theeffect of storage temperatures of 5, 15, 25 and 38°C on seed viability andgerminability of Schoenia filifolia subsp.subulifolia, Rhodanthe chlorocephala subsp.rosea and an unnamed species ofCraspedia. Short-term storage (< 18 months) at cooltemperatures increased seed moisture content, reduced viability and did notpromote germination. However, storage at high temperatures decreased seedmoisture content, maintained viability and improved germination. In tests oflong-term (> 24 months) storage in ambient conditions, both viability andgerminability declined in cohorts of Schoenia andRhodanthe. Detailed tests on 8-month-old seeds ofSchoenia revealed that dormancy was not due tomechanical barriers, as scarification did not improve germination. However,gibberellic acid (GA3) and KNO3applications overcame the dry-storage requirement to break dormancy in thisspecies. High-temperature, dry storage is an important treatment to breakdormancy for planting arid-zone Asteraceae seeds of less than 6 months of age.

Malus ×domestica Borkh. cv. Honeycrisp has been widely planted in North America during the past two decades. However, it is susceptible to many disorders that result in high postharvest losses. Excessive vegetative vigor in apple trees can reduce fruit calcium (Ca) concentrations and increase bitter pit incidence in apple fruit. Plant growth regulators are used routinely in tree fruit orchards to control vegetative growth to increase light penetration into the canopy. The objective of this study was to determine whether shoot growth inhibition using the application of prohexadione-calcium (P-Ca; Apogee®) or stimulation via application of gibberellic acid (GA3; ProGibb®) affected bitter pit incidence in ‘Honeycrisp’ apple. In 2016 and 2017, the experiment was conducted in a commercial ‘Honeycrisp’ orchard with five treatments [untreated control, 62.5 mg·L–1 P-Ca (low P-Ca); 125 mg·L–1 P-Ca (high P-Ca); 16 mg·L–1 GA3 (low GA3); and 32 mg·L–1 GA3 (high GA3)]. Treatments were applied twice during the growing season. Shoot length and the number of internodes for new growth were measured 4 weeks apart after treatment. Overall yield and fruit quality were assessed at harvest, and bitter pit incidence was assessed after 4 months of storage. Low and high P-Ca rates limited shoot growth extension; high GA3 increased shoot extension compared with the untreated control. However, the number of internodes did not change substantially for each shoot. The number of internodes is one of the primary factors affecting leaf area and, consequently, the transpiration balance between fruit and leaves. In both years, treatments with either GA3 or P-Ca did not affect fruit elemental concentration or bitter pit incidence. These results indicate that growth-inhibiting plant growth regulators that reduce shoot extension may not be useful for managing bitter pit incidence in ‘Honeycrisp’ apple.

Chloroplasts play a central role in pathogen defense in plants. However, most studies explaining the relationship between pathogens and chloroplasts have focused on pathogens that infect mesophyll cells. In contrast, the family Luteoviridae includes RNA viruses that replicate and traffic exclusively in the phloem. Recently, our lab has shown that Potato leafroll virus (PLRV), the type species in the genus Polerovirus, forms an extensive interaction network with chloroplast-localized proteins that is partially dependent on the PLRV capsid readthrough domain (RTD). In this study, we used virus-induced gene silencing to disrupt chloroplast function and assess the effects on PLRV accumulation in two host species. Silencing of phytoene desaturase (PDS), a key enzyme in carotenoid, chlorophyll, and gibberellic acid (GA) biosynthesis, resulted in a substantial increase in the systemic accumulation of PLRV. This increased accumulation was attenuated when plants were infected with a viral mutant that does not express the RTD. Application of GA partially suppressed the increase in virus accumulation in PDS-silenced plants, suggesting that GA signaling also plays a role in limiting PLRV infection. In addition, the fecundity of the aphid vector of PLRV was increased when fed on PDS-silenced plants relative to PLRV-infected plants.

In this study, to screen for walnut salt-tolerant rootstocks, Juglans microcarpa L. seedlings were treated in different NaCl concentrations (0, 50, 100, 200, and 300 mmol/L), and the growth situation of seedlings was observed. Moreover, we determined the physiological indexes of seedlings on different days (6, 12, 18, and 24 d) after treatment. The results showed that after salt stress, the external morphology of seedlings displayed salt injury, which manifested as yellowing, withering, curling, and falling off of leaves. High concentrations and long-term stress led to more serious damage, with numerous leaves undergoing withering and shedding. Salt stress significantly inhibited the growth of seedlings. With the increase in salt concentration and stress time, the chlorophyll content and photosynthetic parameters of seedlings reduced to varying degrees; the relative electrical conductivity (REC) and malondialdehyde (MDA) increased. Superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) activities generally increased, followed by a decrease; proline (Pro) accumulated; and soluble sugar (SS) content first increased and then decreased. In addition, it promoted the production of abscisic acid (ABA) and inhibited the synthesis of indole-3-acetic acid (IAA), gibberellic acid 3 (GA3), and zeatin riboside (ZR). It was found that J.microcarpa L. seedlings were more tolerant under 100 mmol/L salt stress, whereas the damage to growth was more severe at 200 mmol/L to 300 mmol/L salt stress.

Pointed gourd (Trichosanthesdioica Roxb.) is a dioecious, cucurbit summer vegetable, and green fruit is the main edible part at 15-18 days after pollination. However, consumer preference goes to fruit without seed since seeds are unpalatable to have after cooking due to their hard seed coat. To overcome this problem by parthenocarpy induction, six types of plant growth regulators [2,4-dichlorophenoxyacetic acid (2,4-D); naphthaleneacetic acid (NAA); N-(2-chloro-4 pyridyl)-N-phenylurea (CPPU); forchlorophenuron (Fulmet); gibberellic acid (GA3) and 2,3,5-triiodobenzoic acid (TIBA) with four concentrations (25, 50, 100 and 200ppm) were sprayed to the unpollinated ovaries of three different female accessions of pointed gourd at anthesis. Results revealed successful parthenocarpy induction by plant growth regulators in all the studied accessions while progressive variation observed in fruit length, diameter and weight according to the differences of plant growth regulators concentrations. The length, diameter and weight of parthenocarpic fruit induced by GA3 at 200ppm, CPPU and TIBA at 100ppm in three studied accessions of pointed gourd were comparable with those of their respective hand-pollinated fruits. In most of the parthenocarpic fruits, seeds were found as empty at ripening stage apart from NAA and GA3 at 200ppm treated fruits had few abnormal seeds. The results confirmed the useful technique of producing seedless fruits in pointed gourd through the application of GA3 at 200ppm, CPPU and TIBA at 100ppm regardless of accessions.

The duration of the dormancy period in tubers is a determining factor in the planning of potato planting and production. The effect of two plant growth regulators on the dormancy period and sprouting of cv. Diacol Capiro tubers was evaluated in this study. The experiment was carried out under storage conditions (15°C and 75% RH) using a completely randomized block design with 3×3×3 factorial arrangement. The factors were: gibberellic acid-3 (GA3) and 6-benzylaminopurine (6BAP) (0, 25, and 50 mg L-1) and the immersion time (iT) (10, 60, and 120 min). The application of GA3 and iT had an effect on dormancy breakage; the treatments with 25 mg L-1 GA3 and 60 min of immersion were enough to reduce dormancy by 18 d (35%) compared to untreated tubers. The factor GA3 increased tuber weight loss (10.2%), generated sprouts with higher weight (25.6-28.4%), higher length growth rate (42.3%), and lower dry matter content (21.8-28.4%), and it increased secondary sprouting (36.2-57.9%) in comparison with untreated tubers. This way, despite the treatments with 25 mg L-1 GA3 reduced the dormancy period, this dose generated sprouts more susceptible to mechanical damage. The treatments with 6BAP did not significantly affect the evaluated variables.

The scope of the microbiological transformation of ent-kaurenoid diterpenes by the fungus Fusarium (Gibberella) fujikuroi which utilise the ent-kaurene and ent-kauren-19-oic acid oxidases and the ring contraction of ring B to gibberellin is reviewed. Constraints arising from the presence of 3α, 15α and 18-hydroxyl groups are noted. The development of a group of potential plant growth regulators which inhibit the ring contraction step in gibberellin biosynthesis is described.

This study aimed to assess the effects of plant growth regulators (PGRs) on stock plant production of mojave sage (Salvia pachyphylla) and ‘Avalanche’ cape daisy (Osteospermum hybrid) that received foliar sprays of the following three PGRs: 200 and 400 ppm ethephon; 250 and 500 ppm benzyladenine; and 50 and 100 ppm gibberellic acid 4 and 7 (GA4+7) plus benzyladenine. Vegetative growth [height and width growth index (GI)], the number of vegetative cuttings, and fresh weight (FW) and dry weight (DW) of the harvested vegetative cuttings data were collected. A propagation study was conducted concurrently to determine the effects of the PGR treatments on rooting vegetative cuttings. GA4+7 plus benzyladenine (50 and 100 ppm) increased the production of both mojave sage and ‘Avalanche’ cape daisy cuttings by ≥18% more than the other treatments. The GI, FW, and DW results showed similar trends across experiments 1 and 2 for each perennial. In the propagation study, the rooting percentage did not differ after 4 weeks, indicating that the use of GA4+7 plus benzyladenine in production protocols could benefit producers of both perennials.

AbstractCapeweed (Arctotheca calendula) seeds were found to be dormant at harvest. Effects of duration and temperature of storage under ‘laboratory’ and ‘natural’ conditions, growth regulators, stratification and age of seeds, were studied on the germination of dormant seeds. Three factors imposed on seeds were found to promote germination of capeweed: (i) allowing seed to age, either in storage, buried in soil or during stratification (germination of 18-month-old seeds was up to 60% higher than that of fresh seeds); (ii) the presence of light (the average germination percentage of seeds exposed to light during storage was 3.2-fold greater than that of seed stored in the dark); and (iii) the application of growth regulators, particularly gibberellic acid, enhanced by scarification (GA3and ethephon promoted germination by up to 58% when applied to scarified seeds). Other factors, e.g. temperature and depth of storage, influenced germination but were less critical to its success. These results provide a preliminary assessment of the importance of these factors in controlling dormancy in seeds of capeweed.

AbstractQuercus species are ecologically and economically important components of deciduous forests of the eastern United States. However, knowledge pertinent to a thorough understanding of acorn germination dynamics for these species is lacking. The objectives of this research were to determine dormancy break and germination requirements for acorns of two eastern United States bottomland species, Quercus nigra and Quercus phellos (Section Lobatae), and to present results within ecological and phylogenetic contexts. Three replicates of 50 acorns of each species received 0 (control), 6, 12 or 18 weeks of cold stratification, followed by incubation in alternating temperature regimes of 15/6, 20/10, 25/15 and 30/20°C. Eighteen weeks of cold stratification were not sufficient for dormancy break in Q. nigra acorns. Cumulative germination percentages at 4 weeks of incubation were ≥77%, but only in incubation temperatures of 25/15 and 30/20°C. Dormancy break in Q. phellos acorns was achieved with 18 weeks of cold stratification, and cumulative germination percentages were ≥87% at 4 weeks of incubation in all test temperature regimes. Gibberellic acid solutions were not an effective substitute for cold stratification in either species. Phylogenetically, Q. nigra and Q. phellos are closely related species and, ecologically, both grow in the same habitat. Acorns of both species possess deep physiological dormancy (PD), but dormancy break and germination requirements differ in acorns of these two Quercus species.

The synthesis and accumulation of tannins on tomato seedlings are regulated by environmental factors. The variation in the content of tannins was sufficiently important to bring about the occurrence of significant differences in the numbers of glasshouse whitefly on the seedlings. During a 2-week experiment, the treatments included mechanical wounding (20 prickings per cm2), spraying with kinetin solutions of 10−4 mol/dm3, plant growth regulators, and the atmosphere enrichment to 680 μmol CO2/mol air, the content of tannins being increased by c. 40, 70, 10–45 and 25% above the values obtained in the control. These results were correlated with a decrease in the numbers of insects occurring on the seedlings by c. 35, 45, 8–29 and 18%, respectively. Contrary to the above results the spraying with solutions of abscisic acid, gibberellic acid, and the incubation of plants in an atmosphere containing 170 μmol CO2/mol air, reduced the content of tannins by c. 69, 22 and 25%, respectively. This was reflected in the respective increases by c. 70, 40 and 35% in the numbers of insects occurring on the seedlings. The obtained results suggest that tannins seem to have a dosage-dependent effect on glasshouse whitefly. Decreasing the host plant quality by increasing tannin content may act as an important selective agent limiting the losses brought about by glasshouse whitefly in tomato cultivation.

Sexual seeds of potato (Solanum tuberosum L.) usually emerge poorly under high-temperature conditions (> 25 C). A seedling vigor study was conducted during the warm season (1988-89) in Lima, Peru, and the results of two representative tests. are reported. Two presowing treatments and a rinsed control were compared for seedlingstand establishment in a screenhouse with old (>18 months) and new (> 6 months) sexual seeds of three potato crosses. The treatments consisted of soaking the seed in solutions of KN03 + K3P04 at – 1.0 MPa (priming) and gibberellic acid at 1500 ppm (GA1500). Seedling vigor was lower at 34C (February test) than at 29C (November test). In both tests, overall seedling performance was highest in seed of the cross Atlantic × LT-7. Old seed was more vigorous than new seed, particularly when the crosses Atzimba × R128.6 (B2) and Serrana × LT-7 (Cl) were tested at 34C. Priming increased percentage of early (10 days) emergence over the other treatments at 34C and increased seedling dry weight in both tests. GA1500 increased percentage of final (17 days) emergence in crosses B2 and Cl, as compared to rinsing, except at 29C, where there were no significant differences in old seed. For sowing true potato seed at high temperature, a) the genotype is a crucial factor, b) sufficient seed storage (> 18 months) may be essential, and c) seed priming is more effective than the standard GA1500 treatment.