GA3 Solution Research Articles

Study on Dormant and Germination Characteristics of Chinese Olive (Canarium album) Seeds

This study aimed to determine the dormancy type of Chinese olive seeds and improve their germination rate. The water permeability and germination-inhibiting substances of Chinese olive seeds were assessed. Low-temperature stratification and soaking in a GA3 solution were implemented to measure the time lag, initial time, germination rate, and germination potential of the seeds. The findings revealed that the seed coat exhibited poor water permeability, which negatively influenced the germination rate. Additionally, Chinese olive seeds contained substances that inhibited germination. The duration of low-temperature stratification (at 4 ± 1 °C) gradually diminished the dormancy of Chinese olive seeds, resulting in early and rapid germination. The germination rate significantly increased, with the percentage of seed germination rising from 0% to 42.33% within 60 days of stratification. Furthermore, combining low-temperature stratification with different concentrations of GA3 notably enhanced the germination rate. The optimal concentrations of gibberellins for 40 and 60 days of stratification were determined to be 300 and 100 mg/L, respectively. These results indicate that Chinese olive seeds possess non-deep physiological dormancy.

Seed dormancy and after-ripening requirements of Indian lac tree (Schleichera oleosa Lour. Oken)

ABSTRACT After-ripening (AR) is a time and environmental regulated process which determines the germination potential of the dry seeds. The after-ripened seeds swell after absorbing water and initiates metabolic activity linked to the germination process. Such after-ripening process is not studied in detail in Schleichera oleosa species. Therefore, an experiment was designed to assess the effect of different pretreatments on seed dormancy and AR patterns in the seeds of S. oleosa. The seeds were subjected to various pre-treatments, viz., mechanical scarification, scarification + Gibberellic acid (GA3, 0.02% and 0.05%), scarification + KNO3 (0.02% and 0.05%) for 24 hours. Further, the seeds were desiccated at four levels (10, 12, 14 and 16%) of intact seed water content (SWC) and were kept at either uncontrolled ambient room temperature or controlled constant temperatures (22°C, 25°C and 28°C), and their germination was tested fortnightly for 60 days. The results revealed that S. oleosa possess combined physical+ physiological dormancy and soaking of scarified seeds in GA3 solution (0.05%) for 24 hours showed the maximum germination percentage (80.0%), vigour index (721.4), and mean germination time (6.6 days). Results also indicated that AR process under optimum conditions (25°C, 16% SWC and 60 days) can increase germination percentage up to six times (81.25%) as compared to freshly collected seeds (12.5%) in the species. These findings can be utilized for developing the seed germination protocol with the aim to devise the propagation techniques and conservation programme for the species.

The Impact of Magnetic Field and Gibberellin Treatment on the Release of Dormancy and Internal Nutrient Transformation in Tilia miqueliana Maxim. Seeds

The seeds of Tilia miqueliana Maxim. exhibit deep dormancy, which is categorized as combinational dormancy. This study utilized a comprehensive treatment involving magnetic fields, gibberellin (GA3), and cold stratification to promote the release of seed physiological dormancy and enhance germination rates. After being soaked in 98% H2SO4 for 15 min, mature seeds of Tilia were exposed to magnetic field treatments (150 MT, 250 MT) for different durations (25 min, 45 min, 65 min, and 85 min), as well as GA3 solution soaking (concentration: 0 μmol·L−1, 1443 μmol·L−1). Subsequently, cold stratification (0–5 °C) was applied to investigate the effects of these treatments on seed dormancy release and nutrient transformation. The results indicated that the comprehensive treatment involving magnetic field, GA3 solution soaking, and cold stratification effectively released the physiological dormancy of Tilia seeds and improved germination rates. Among the treatments, M150T85G1443 (magnetic field intensity: 150 MT, magnetic field treatment time: 85 min, GA3 soaking concentration: 1433 μmol·L−1) exhibited the most favorable outcome. After 75 days of cold stratification following the comprehensive treatments, the germination rate of M150T85G1443 seeds reached 89%. Additionally, the levels of storage substances such as starches and crude fats within the seeds decreased, while the utilization of soluble sugars and soluble proteins increased. The M150T85G1443 treatment exhibited the highest degree of variation, leading to gradual increases in metabolic activities of the seeds and a transition from dormancy to germination.

An insight into seed priming response of Crotalaria ochroleuca and Crotalaria spectabilis during storage.

The proper establishment of plants is essential for the efficient use of resources such as water and light. Besides, even after seed storage and sowing the uniform establishment of plants is essential for their success. Crotalaria ochroleuca and Crotalaria spectabilis are important medicinal plants with poor seed germination rate, occasionally. The effects of seed priming in both C. ochroleuca and C. spectabilis were evaluated in seed performance even after seeds storage for up 90-days. Experimental assays were performed in a randomized design with gibberellic acid (GA3, 100 ppm), polyethylene glycol (PEG 6000, -0.2 MPa) and PEG (-0.2 MPa) + GA3 (100 ppm) solutions during seed priming in four replicates. Seeds not submitted to priming treatments constituted control. Seeds physiological performance were evaluated immediately and even after 30, 60 and 90-days seed dry-storage. The data obtained in each experiment were submitted to variance analysis (ANOVA) adopting a confidence level of 95%. The effects of seed priming with PEG and GA3 during seed ageing were significant for germination variables of C. ochroleuca and C. spectabilis. During dry storage, seed viability of both species gradually decreased and the first symptoms were delayed seed germination, especially more evident for C. ochroleuca, even in primed or non-primed seeds. Afterwards, C. ochroleuca seeds previously GA3 primed had higher results of root protrusion (86%), hypocotyls elongation (76%) and complete seedlings (75%) than non-primed seeds (control). These findings shown a good potential of hormopriming to attenuate damage during the seed aging of C. ochroleuca.

Seed priming as a method of preservation and restoration of sunflower seeds

The study focused on determining the preservative and restorative effects of seed priming with gibberellic acid (GA3) and potassium nitrate (KNO3) on sunflower seeds against deterioration. The seeds were immersed in different concentrations (0, 250, 500, and 1000 mg L−1) of GA3 and KNO3 solutions before and after being subjected to accelerated aging (AA). Unprimed seeds (NT) were used as control. The results showed that AA led to a reduction in germination percentage, germination index, and seedling growth parameters. However, seed primed with GA3 had a higher germination percentage after AA than NT. All seed primings shortened mean germination time and improved germination index. Seedling growth was stimulated by seed priming, and seed priming after AA produced more vigorous seedlings than primed seed before AA because they were severely affected by AA. In addition, hydration sufficiently induced the germination and seedling growth of aged seeds. A significant difference was found between GA3 and KNO3, and seeds were effectively protected from aging by GA3, while hydration promoted germination of aged seeds. Consequently, the recovery effect of seed priming was more pronounced than the conservative effect, and sunflower seeds should be primed with 500-1000 mg L−1 GA3 before storage or, if this is not possible, hydration improves the vitality and subsequent growth of aged sunflower seeds.

Assessment of Various Gibberellic Acid Concentrations on Seed Germination and Seedling Growth of Chilgoza (Pinus gerardiana Wall. ex D. Don)

Chilgoza (Pinus gerardiana) forests naturally exist on the highest elevations of the Himalaya Mountains in the provinces of Paktia, Kunar, Nangarhar, Nuristan, and Paktika in the southeast of Afghanistan. These natural chilgoza forests provide a sizable source of income for the people living in these areas. The spread and natural regeneration of chilgoza pine forests is declining in the natural environment as a result of overharvesting, erratic annual seed production, and prolonged dormancy; therefore, it is necessary to find an effective method to enhance seed germination and seedling growth. Different Gibberellic Acid (GA3) hormone concentrations (50 ppm, 75 ppm, and 100 ppm), the removal of the seed coat, and control (untreated) treatments were used to conduct an experiment for this study. For each treatment, seedling growth parameters and the percentage of seeds that germinated were examined. The results showed that the T4 treatment had the highest average length of seedling, shoot, and root, measuring 13.34 cm, 8.1 cm, and 8.4 cm, respectively; whereas the T1 treatment had the shortest average lengths of seedling, shoot, and root, measuring 11.22 cm, 6.5 cm, and 6.2 cm, respectively. The greatest percentage of germination (78.66%) was observed in T4 (100 ppm), whereas the lowest percentage (26%) was documented in T1 (Control). The highest average number of leaves was recorded in T4 (22.25) and the lowest in T1 (15.02) treatment. The results indicated that treating chilgoza pine seeds in a 100 ppm solution of GA3 for 24 hours enhances both the seed germination and sprouting seedling growth.

The Effects of Gibberellic Acid and Cane Girdling of Applications on Crimson Seedless Grape Variety of Cluster and Berry Characteristics

‘Crimson Seedless’ grape variety is a late maturity and small berry size. Berry size is one of the most important quality parameters of table grapes. This trial was carried out in the Crimson Seedless (Vitis vinifera L.) grower vineyard in Sarıgöl (dadağlı) locality of Manisa province in the 2022 vegetation period. A randomized complete block design was used with vines as blocks and clusters as the experimental unit’s four treatments and four replications. Vine bunches of Crimson Seedless grape variety, ten years old, were sprayed extensively with a GA3 (Gibberellic Acid) solution (20 mg L-1) on the 25th of April 10th of May, and 10th of June/2022, while girdling (G) was applied from removing 3 mm diameter bark all around from 10 cm below the top of the vine trunk at fruit set stage. Control (C) only water was sprayed. This study aimed to reveal gibberellic acid and cane girdling applications on Crimson Seedless cluster and berry characteristics. Harvest (oBrix 19) was done on the 10th of October/2022 and after that, the cluster weight (g), cluster length (cm), cluster width (cm), berry weight (g), berry length (mm), berry diameter (mm), berry length/berry diameter, total soluble solid, total acidity and maturity index were determined in fresh fruit samples randomly taken from each vine. It was found that all applications generally had statistically (P

Sowing Media and Gibberellic Acid Influences Germination and Seedling Growth of Chilgoza Pine (Pinus gerardiana. Wall)

Pinus gerardiana Wall. recognized for its significant contribution to nut production, holds ecological and economic importance as a forestry species with limited range primarily found in Afghanistan. The species displays either extremely low or non-existent levels of natural regeneration. Due to irregular and uncommon seed years, problems with dormancy, and other factors, this species' natural habitat renewal is slowed down. Hence, we conducted a study to examine how different substrates and gibberellic acid (GA3) affect the germination and growth of Chilgoza pine seedlings. The substrates were grouped into three types, each containing varying proportions of soil, sand, and farmyard manure (FYM): M1 (1:1:1), M2 (1:1/2:1/2), M3 (1:1/3:2/3). Additionally, three concentrations of GA3 (0, 50, and 100 ppm) were used to assess their impact on germination and seedling growth. The results revealed that, with the exception of mean germination time (MGT) at 42.36 days, the highest values for final germination percentage (FGP) at 58.66%, germination index (GI) at 274, germination rate index (GRI) at 75.01, shoot fresh weight (SFW) at 8.74 g, shoot dry weight (SDW) at 4.78 g, shoot length (SL) at 219.80 mm, and seedling vigor index (SVI) at 1291926.02 were achieved when seeds were initially soaked in a 100 ppm GA3 solution for 6 hours and then planted in a medium with equal proportions of soil, sand, and FYM. The effects of GA3 concentrations were significant in influencing seedling growth, while substrate effects strongly impacted seed germination. This indicates that Chilgoza seeds possess ample gibberellin for germination but this is reduced during the seedling growth phase. The response of seedling vegetative growth to GA3 concentrations exhibited a notable linear trend, whereas the relationship between FGP and MGT with GA3 concentrations showed a significant quadratic pattern. This suggests that GA3 concentrations can effectively promote seedling growth. The substrate choice notably influenced FGP and MGT due to its role in nutrient provision and aeration. The highest GA3 concentration led to the greatest enhancement in seedling vegetative growth, implying that prolonged usage might yield further benefits over time. In conclusion, the findings suggest that both GA3 and substrate have the potential to enhance Chilgoza seed germination and subsequent seedling growth, and their combined application could be a beneficial approach.

Comparative efficacy of priming treatments and storage periods in overcoming seed dormancy in round gourd (Praecitrullus fistulosus (Stocks) Pangalo)

Owing to its hard seed coat, the seeds of Praecitrullus fistulosus exhibit dormancy which impairs the germinability and subsequent seed establishment. To overcome this dormancy, the seeds are required to be stored for a minimum of 45 days after harvest (DAH). In north Indian plains, round gourd seeds are harvested in mid-June and are required to be sown immediately in June-July. Therefore, priming treatments were employed to overcome seed dormancy in a short interval. To assess the effect of various priming treatments in overcoming dormancy, the seeds were stored at room temperature for various durations and at the end of the storage period, the seeds were primed by soaking in solutions of GA3 (150 µgmL-1, 500 µgmL-1,1000 µgmL-1 gibberellic acid), cytokinin (150 µgmL-1, 500 µgmL-1,1000 µgmL-1kinetin), ethylene (150, 500, 1000 ethrel), KNO3 (150 and 500 µgmL-1), HNO3 (150 and 500 µlL-1) and water, at 250C for 12 hours and 24 hours, respectively. Among all the priming treatments, 500 µgmL-1 KNO3 for 24 h enhanced percentage germination to more than 60 per cent in freshly harvested seeds to more than 80 per cent in seeds stored for 15 DAH. It also enhanced the length of seedling, vigour index (SVI-I and SVI-II), and coefficient of rate of germination (CRG) with a reduction in the mean days taken for germination (MDG).

Overcoming dormancy in seeds of Bixa orellana L.

Annatto seeds, Bixa orellana L., have dormancy mechanisms that make their germination difficult, requiring testing of different methods to enable their reproduction. Thus, the objective was to evaluate the emergence of Bixa orellana seeds submitted to solutions and periods of imbibition to overcome dormancy. The experimental design was completely randomized, with a 4×2 factorial arrangement. The evaluated seeds were from the red Piave cultivar, with a solution of distilled water and gibberellic acid (GA3) at a concentration of 125 mg L-1 in the imbibition periods of 0, 4, 10, and 24 hours. Emergence test, shoot height, stem diameter, root length, shoot, and root dry matter, and Dickson's quality index was evaluated. The solutions did not interfere with the development of the plants in the periods. It was concluded that annatto seeds in a GA3 solution for a period of 24 hours are efficient for overcoming dormancy.

Morpho-physiological studies on in vitro germination of Berberis empetrifolia Lam. (Berberidaceae)

Berberis empetrifolia is an endemic species from Chile that produces some bioactive compounds, highlighting the alkaloid berberine, which demonstrated antitumor properties. Taking into account the constant plant supply demand required for medicinal use, the establishment of in vitro propagation protocols allows plant multiplication, without affecting natural populations. Moreover, the in vitro germination is an efficient strategy to obtain axenic plants. The aim of this study was to establish the in vitro germination and to characterize seeds morphology and seedling development of B. empetrifolia. After decontamination of seeds, pre-germinative treatments were applied. Seed viability ranged from 75-90% and the embedding curve revealed permeable integument. The germination was characterized as epigeal phanerocotylar type. Seeds not submitted to pre-germinative treatments reached 10-30% germination rate (GR) and showed asynchronous germination. The most efficient pre-germinative treatment was the storage of seeds at 3˚C for 12 days followed by overnight soaking in GA3 solution associated to seed coat removal. This treatment allowed the seed dormancy to be overcome, reaching GR above 95% and resulting in synchronous germination. The in vitro germination protocol established for B.empetrifolia was efficient to produce phenotypically normal axenic seedlings, allowing their use as source of plant material for biotechnological, phytochemical and pharmacological studies.

Effects of exogenous GA3 and warm water on dormancy breaking germination characteristics of Eucommia ulmoides

Seeds of the plant Eucommia ulmoides Oliver, have prominent dormant characteristics. In the present study, seed dormancy and germination of E. ulmoides were investigated by treating them with exogenous GA3 and different water temperatures. The results revealed that exogenous GA3 and warm water soaking treatments were beneficial to the dormancy breaking and germination of seeds. The germination rate of seeds treated with 50℃ water was 84.67%. In comparison, the seeds treated with 300 mg·L-1 GA3 had only a germination rate of 45%. This low germination rate resulted probably due to the low temperature of the GA3 solution. Another important reason is the presence of eucommia gum in the seed coat of E. ulmoides which hinders the germination process. During germination, the SOD activity in the seeds treated with GA3 (300 mg·L-1) and warm water (50 °C) increased significantly. Increased SOD activity reduced the degree of oxidative damage of the plasma membrane and resulted a continuous decrease in TBARS content. Thereby, the seeds were prompted to develop in a direction conducive to germination. In addition, GA3 (300 mg·L-1) and warm water (50℃) treatments increased the content of endogenous GA3, IAA, and ZR in the seeds, and decreased the content of endogenous ABA. This had resulted significantly higher ratios of GA3/ABA, IAA/ABA and ZR/ABA than those ratios of distilled water (room temperature) treated plants. In short, 50 °C warm water treatment has a more marked germination promoting effect on E. ulmoides seeds.

Effect of Sowing Media and Gibberellic Acid on seed Germination and Seedling Growth of Chilgoza pine nut (Pinus gerardiana. Wall)

Chilgoza is currently propagated only by seed, which shows very low and uneven germination, and slower seedlings growth that causes poor natural regeneration. Therefore this study was undertaken to investigate the effects of gibberellic acid and sowing media on seed germination and seedling growth. Two factors i.e., sowing media (three media with various proportions of soil, sand, and animal manure) and GA3 (0, 50, and 100 mg. L-1) were included in the study. This greenhouse experiment was run as 3×3 factorial in frame of CRD design with 3 replications. Results showed that apart from MGT (42.36 days), the higher FGP (58.66%), GI (274), GRI (75.01), and SFW (8.74gr), SDW (4.78gr), SL (219.80 mm), SVI (129192602) were obtained when seeds were initially immersed for 6 h at 100 mg. L-1 GA3 solution and then sown in the medium of equal proportions of soil, sand, and animal manure. In terms of simple effects, GA3 concentrations had a significant effect on the vegetative growth of seedlings, whereas media effects on seed germination were highly significant which means that chilgoza seed contains sufficient amount of gibberellin for germination and thereafter is reduced during seedling growth stages. The results also revealed that the vegetative growth response of the seedling to the concentrations of GA3 had a significant linear response but response of FGP and MGT against GA3 concentrations were significantly quadratic i.e. the use of GA3 concentrations can stimulate the growth of seedlings. Overall the results showed that the media had obvious effect on FGP and MGT which may be due to nutrients and ventilation. On the other hand, as the highest concentration of GA3 increased the vegetative growth of the seedling, so additional use may be necessary over time. In light of the results, it is suggested that GA3 in addition to media may be used for betterment of chilgoza seed germination and subsequent seedling growth.

Influence of Foliar Application of Growth Regulators on Vegetative Growth and Flowering Of Chrysanthemum

The pot experiment was conducted at the Floriculture field of Horticulture Research Centre (HRC), Bangladesh Agricultural Research Institute (BARI), Gazipur during August 2020 to May 2021 to evaluate the foliar spray of gibberellic acid (GA3), benzyl adenine (BA) and naphthalene acetic acid (NAA) on growth and flowering traits of chrysanthemum (Chrysanthemum morifolium). The experiment was laid out in Randomized Complete Block Design (RCBD) with three replications. Four weeks old seedlings of chrysanthemum genotype CM-019 (flower class: Pompon and flower colour: Orange yellow) were transplanted in pot keeping under natural sunlight. The aqueous solution of GA3, BA and NAA @ 100 and 200 ppm of each were sprayed on the flower plants at monthly interval starting after one month of transplantation of seedlings along with control (water). The results revealed that vegetative growth and flowering parameters were significantly influenced by plant growth regulators. Maximum number of leaves per plant (50.0) and leaf area per plant (7.5 cm2) were recorded from the spraying of BA @ 100 ppm closely followed by BA @ 200 ppm (48.0 and 7.0 cm2/plant) and GA3 @ 100 ppm only for number of leaves (47.0/plant). Spraying of GA3 @ 100 ppm produced the tallest plant (70.0 cm) and the highest plant spread (23.0 cm). Number of flowers (26.0/plant), flower size (7.8 cm), average weight of stalk (37.0 g) and vase life (15.0 days) were also found maximum from the application of GA3 @ 100 ppm, closely followed by GA3 @ 200 ppm (23.5/plant, 7.2 cm, 36.0 g, 14.0 days) and NAA @ 100 ppm (18.5/plant, 7.0 cm, 36.0 g, 13.0 days) and irrespective of concentrations, BA failed to improve these characters. GA3 @ 100 ppm recorded maximum length of stalk (37.5 cm) and rachis (29.0 cm), which was identical with GA3 @ 200 ppm (34.6 cm and 25.0 cm), and BA @ 100 ppm gave the lowest length of stalk and rachis. GA3 also caused faster initiation of flowering, whereas NAA and BA delayed it. GA3 @ 100 ppm took the minimum days to flowering (50.0 days) was observed when plants were sprayed with GA3 @ 100 ppm whereas it was maximum (69 days) from BA @ 100 ppm treatment. It can be concluded that GA3 @ 100 ppm provided the best results for obtaining better vegetative growth of plants, maximum number of cut blooms with longer stalk as well as bigger flower size with prolonged vase life in chrysanthemum.
 Bangladesh J. Agril. Res. 47(1): 69-80, March 2022

Influence of Seed-Covering Layers on Caper Seed Germination.

Caper is a perennial shrub that is widespread in the Mediterranean Basin. Although the fruits contain many seeds, they germinate slowly and with very low percentages, due to their nondeep physiological dormancy. The influence of the testa and endosperm, as well as the effect of applying gibberellic acid (GA3) solutions on seed germination to release its dormancy, are reported in this study. The mechanical resistance exerted by the testa and endosperm against radicle protrusion in mature caper seeds was measured. The best germination results were obtained with seeds devoid of testa wetted with water and with intact seeds wetted with a 500 mg L-1 GA3 solution, without statistical differences between them. The GA3 addition triggers an increase in both the content of endogenous gibberellins (GA) and the GA/abscisic acid ratio, increasing germination. Its germination consists of two temporally separated events: testa cracking and endosperm piercing. Testa cracking begins in the hilum-micropillar area; it involves a signal from the embryo, which GA can replace, possibly by increasing the growth potential of the embryo. After testa cracking, the radicle emerges through a hole in the micropylar endosperm. The puncture force necessary to pierce the micropylar endosperm decreased drastically during the first day of imbibition, remaining practically constant until testa cracking, decreasing afterwards, regardless of the addition or not of gibberellins.

Defect Chemistry in Zn3V4(PO4)6

Zinc-ion batteries have attracted great interest for their low cost, safety, and high energy density. Recently, Zn3V4(PO4)6 has been reported to be a promising cathode material for zinc-ion batteries. The defect chemistry, diffusion of Zn-ions, and solution of dopants are examined by advanced simulation techniques. The simulation results show that the most favorable intrinsic defect is the Zn-V anti-site. A zig-zag pattern of long-range Zn2+ diffusion is observed and the activation energy of 1.88 eV indicates that the ionic conductivity of this material is low. The most promising isovalent dopants on the Zn site are Ca2+ and Fe2+. Although the solution of Ga3+, Sc3+, In3+, Y3+, Gd3+, and La3+ on the V site is exoergic, the most promising is In3+. Different reaction routes for the formation of Zn3V4(PO4)6 are considered and the most thermodynamically favorable reaction consists of binary oxides (ZnO, V2O3, and P2O5) as reactants.

Influence of Salicylic Acid and Gibberelic Acid on Germination and Growth of Bitter Gourd, Momordica charantia L.

Aim: Uniform and rapid germination and growth is a major barrier to successful crop production of bitter gourd, a major summer vegetable of Bangladesh. Seed priming with different signaling molecules can efficiently confer this problem. Therefore, the present study was conducted to explore the potentiality of different signaling molecules such as salicylic acid (SA) and gibberelic acid (GA3) to increase germination and growth of bitter gourd.
 Place and Duration of the Study: The study was conducted in the Department of Seed Science and Technology, Bangladesh Agricultural University, from September-October, 2022.
 Methodology: The bitter gourd seeds were soaked in 1mM, 2mM and 3mM GA3, and 3mM, 6mM and 9mM SA solutions for 1 hour. The untreated seeds were used as control. Seeds were germinated in petri dishes and data on germination was collected. Then seedlings were transplanted to pot after 7 days to record growth parameters at 15th day of establishment.
 Results: The experiment's findings indicated that lower concentrations of SA and GA3 had a beneficial effect, however greater levels significantly reduced the bitter gourd's ability to germinate and develop in comparison to the control. Findings of the study showed priming concentrations of 3mM SA, 6mM SA, and 1mM GA3, markedly improved the germination percentage, shoot and root length, seedling vigour, and fresh and dry weight of the shoot and root, RWC of bitter gourd.
 Conclusion: Pretreatment with SA and GA3 was observed to be relatively more efficient in increasing germination of bitter gourd compared with control. Overall, this study suggests that bitter gourd seed priming 3mM SA, 6mM SA, and 1mM GA3 can improve germination and growth.

Effects of Gibberellin Pre-Treatment on Seed Germination and Seedling Physiology Characteristics in Industrial Hemp under Drought Stress Condition.

The present study aimed to explore the effects of exogenous gibberellins (GAs) on seed germination and subsequent seedling growth of hemp (Cannabis sativa L.) under drought stress. Seeds of two industrial hemp cultivars i.e., 'Yunma 1', (YM) and 'Bamahuoma', (BM) were treated with different concentrations of GA3 solution (0, 200, 400, 600, 800 mg/L) at 20 °C for 8 h. The effect of pre-treatment was assessed on germination characteristics and physiological indexes on subsequent exposure to drought stress using 20% (m/v) polyethylene glycol (PEG) for 7 days. The results revealed that seed germination in hemp was sensitive to drought stress, as the germination indexes (germination rate and germination potential) decreased significantly, and seedling growth (hypocotyl length and radicle length) was impeded under 20% PEG-6000 condition. GA3 pre-treatment affected germination rate, germination potential, hypocotyl length and radicle length. With increasing GA3 concentration, these indexes first increased and then decreased. For seedling physiology characteristics in hemp, GA3-pretreatment remarkedly increased the osmotic regulating substances (soluble sugar and soluble protein contents) and the activities of antioxidant enzymes (SOD, superoxide dismutase and POD, peroxidase), while sharply decreased the lipid peroxidation (malondialdehyde, MDA) in seedlings grown under PEG-6000 induced drought stress. These results suggested that seeds pre-treated with GA3 could enhance the drought tolerance of hempseeds, and the optimal effect of GA3 for seed pre-treatment of YM and BM could be obtained when the concentration of GA3 solution reached 400 mg/L and 600 mg/L, respectively.

Jatropha curcas L. as a Plant Model for Studies on Vegetative Propagation of Native Forest Plants.

Highlights Jatropha curcas L. has great potential to be used as a model plant in several studies involving native forest species.The immersion in the 2,4-D solution accelerated the emission of primary roots in hardwood cuttings.Studies on vegetative propagation of native species can use Jatropha curcas L. species as a model for obtaining important information in a short time and reducing labor costs.The immersion of cuttings of native species in solutions with low concentrations of 2,4-D can favor the rooting process and vegetative propagation. Even though it is a forest native plant, there are already several studies evaluating the small genome of Jatropha curcas L., which belongs to the Euphorbiaceae family, and may be an excellent representative model for the other plants from the same family. Jatropha curcas L. plant has fast growth, precocity, and great adaptability, facilitating silvicultural studies, allowing important information to be obtained quickly, and reducing labor costs. This information justifies the use of the species as a model plant in studies involving the reproduction of native plants. This study aimed to evaluate the possibility of using Jatropha curcas L. as a model plant for studies involving native forest plants and establish possible recommendations for the vegetative propagation of the species using hardwood cuttings. The information collected can be helpful to other native forest plant species, similar to Jatropha curcas L. To this end, the effects of hardwood cutting length (10, 20, and 30 cm) and the part of the hardwood cuttings (basal, middle, and apex) were evaluated. Moreover, the influence of immersing the hardwood cuttings in solutions containing micronutrients (boron or zinc) or plant regulators (2,4-D, GA3) and a biostimulant composed of kinetin (0.09 g L−1), gibberellic acid (0.05 g L−1), and 4-indole-3-butyric acid (0.05 g L−1). The experiments were carried out in duplicates. In one duplicate, sand was used as the substrate, and rooting evaluations were made 77 days after planting. In another duplicate, a substrate composed of 50% soil, 40% poultry litter, and 10% sand was used, and the evaluations of the saplings were performed 120 days after planting. The GA3 solutions inhibited the roots’ and sprouts’ emissions, while immersion in 2,4-D solution increased the number of primary roots at 77 days after planting. The hardwood cuttings from the basal part of the branch had the best results for producing saplings.

Cuticular wax metabolism of lemon (Citrus limon Burm. f. Eureka) fruit in response to ethylene and gibberellic acid treatment

The brightness and color of lemon fruit directly determine its commodity value. Ethylene (ETH) and gibberellic acid (GA3) treatment are widely adopted to achieve postharvest uniform peel color, which may affect fruit surface brightness. Fruit brightness is closely associated with cuticular wax. However, little is known about how ETH and GA3 treatment affect cuticular wax metabolism in lemon fruit. Here, we treated green lemon fruit with ethephon and GA3 solution, and analyzed the changes in wax crystal morphology, chemical composition and expression levels of wax-related genes during storage. ETH increased the density and size of platelet-like wax crystals. Moreover, ETH accelerated cuticular wax accumulation, particularly alkanes and aldehydes, while GA3 inhibited these processes. ETH treatment increased the total wax content by 56% after four-day storage, particularly very-long-chain (VLC) alkanes (by 83%), while GA3 decreased the total wax content by 53% after fourteen-day storage, particularly VLC alkanes (by 56%). The main differentially expressed genes, including those involved in total wax accumulation (KCS19–1 and KCS19–2) and transformation of VLC aldehydes to VLC alkanes (CER1–1 and CER3), were up-regulated by ETH treatment while down-regulated by GA3 treatment. In summary, ETH accelerates and GA3 inhibits the accumulation of total wax, VLC aldehydes and VLC alkanes. I In addition, ETH and GA3 treatment have little effect on the intrinsic quality, but can alter the membrane lipid property and oxidase activity of fruit.