Interactions of Applied Hormones in the Germination of Lepidium Virginicum Seeds

Author Institution: Department of Botany, The Ohio State UniversityTests of the germination response of light sensitive Lepidium virginicum seeds to applied gibberellic acid confirmed earlier reports that gibberellic acid can substitute for red light. Further tests indicated that promotion of germination by either red light or gibberellic acid can be nullified by abscisic acid. Dark incubation of the seeds in kinetin alone resulted in only slight promotion of germination. Combinations of suboptimal gibberellic acid plus kinetin did not enhance germination to a level greater than that for kinetin alone. Optimal concentrations of gibberellic acid plus kinetin can reverse inhibition of certain abscisic acid concentrations. A comparison of these responses with those of Grand Rapids variety of lettuce seed was made

The Effects of Gibberellin on Dwarf Plants

In this study, conducted by the students above, gibberellic acid was added to both dwarf and wild-type Setaria Viridis seedlings. Applying gibberellic acid to the dwarf plants was testing to see if there was a direct effect on gibberellic acid to the heights (in cm) of the seedlings. The wild-type seeds were also tested in order to see if there is an effect of them also. Gibberellic acid was applied to a group of dwarf and wild-type seedling, there was an additional group of seedlings that were also just treated to normal conditions (simply just watering) as a control group. The main goal of this study was to identify whether certain dwarf mutants are unable to process and take up gibberellic acid or have a gibberellin deficit

Perbaikan Pembungaan Dan Pembijian Beberapa Varietas Bawang Merah Dengan Pemberian Naungan Plastik Transparan Dan Aplikasi Asam Gibberelat

The main problem in producing true shallotseed (TSS) as source of healthy seed in Indonesia is low flowering and seed set of shallots. The experiment was conducted atExperimental Garden of Indonesian Vegetable Research Institute (IVEGRI), Lembang (1,250 m asl.) from May to November2010. Objective of the study was to evaluate the effect of varieties, gibberellic acid, and transparent plastic shelter on flowering andtrue seed forming of shallots. A split plot design with three replications was used in this experiment. Main plots were three shallotvarieties i.e. Allium ascalonicum cv. Maja, Bima, and Kuning. Subplots were four combinations of gibberellic acid and transparentplastic sheltering i.e. (1) no sheltering and gibberellic acid applying; (2) no sheltering and applying 200 ppm gibberellic acid; (3)transparent plastic sheltering and no gibberellic acid application, and (4) transparent plastic sheltering and application of 200 ppmgibberellic acid. Before planting, mother bulb seed were vernalized in 10oC for 3 weeks. The results showed that there was interactionbetween variety, gibberellic acid, and transparent plastic sheltering on percentage of shallots plant number which produced flower.The highest percentage of shallots plant number producing flower up to 54.06% was obtained on A. ascalonicum cv. Bima withoutapplication of transparent plastic sheltering and gibberellic acid. The highest yield of TSS, viz. 16.11 kg/ha for Maja and 13.07 kg/ha for Bima was determined on application of transparent plastic sheltering and 200 ppm gibberellic acid. The flowers of Kuningvariety did not produce TSS because the flowers were attacked by fungi diseases. The quantity and quality of TSS yield were stilllow due to unsupporting weather for the flowering and seedling of shallots optimally

Morphogenesis, pigment content, phytohormones and yield of tomatoes under the action of gibberellin and tebuconazole

One of the main tasks of contemporary plant physiology is regulation of growth and development of cultivated plants in order to optimize the productive process. The scientific community focuses its attention on the use of natural activators and growth inhibitors. We investigated the effect of foliar treatment with 0.005% solution of gibberellic acid and 0.025% solution of the anti-gibberellic preparation tebuconazole on morphogenesis, leaf mesostructure, content of photosynthetic pigments, balance of endogenous phytobrybrides and lymphocyte B and productivity of tomatoes. The vegetation experiment was carried out in the conditions of soil-sand culture in vessels with a 10-liter volume. The treatment was carried out in the budding phase. Morphometric parameters were measured every 10 days. The mesostructure of the middle tier leaves was studied in the fruit formation phase, and the chlorophyll content was determined in the raw material by spectrophotometric method. Analytical determination of endogenous phytohormones – indolyl-3-acetic (IAA), gibberellic acid and abscisic (ABA) acids and cytokinins – zeatin (Z), zeatin-O-glucoside (ZG), zeatinribozide (Znila) and isopentenyladenosine (iPA) was performed by high performance liquid chromatography – mass spectrometry (HPLC-MS). With gibberellic acid treatment plant height increased significantly, while with tebuconazole it decreased. Gibberellic acid increased the number of leaves per plant, and tebuconazole did not change it. The preparations increased the number of leaf blades per leaf, the total number of leaf blades per plant, the weight of the raw material of leaves, the area of leaf blades and the area of the leaves at the end of the study period. The dry matter weight of stems and roots under the action of gibberellic acid increased, and during the treatment of tebuconazole decreased. Gibberellic acid increased the dry matter of the whole plant, and tebuconazole did not change it. Under the action of tebuconazole the content of chlorophyll in the leaves increased, while under the action of gibberellic acid it decreased. Both regulators increased the volume of columnar parenchyma cells. Gibberellic acid increased the size of spongy parenchyma cells, while tebuconazole did not change them. It is revealed that the action of exogenous gibberellic acid in stems and leaves increased the content of endogenous IAA and gibberellic acid, and tebuconazole decreased their content. The ABA content in stems and leaves increased with tebuconazole treatments and decreased with exogenous gibberellic acid. The total cytokinin content in the leaves was higher than in the stems in both the control and the experiment samples. Growth regulators induced an increase in the cytokinin pool in leaves and a decrease in stems. Gibberellic acid increased the content of all five forms of cytokinins in the leaves, and tebuconazole increased only two isoforms. In the stems under the action of both growth regulators the content of Z decreased and iP increased. The content of ZR and iPA in stems increased after the application of the retardant and decreased under the action of growth stimulant. The ZG content exceeded the control after gibberellic acid treatment and was in trace concentrations under the action of tebuconazole. Growth regulators optimized the productivity of tomato plants: under the action of gibberellic acid there was a considerable increase in the number of fruits per plant, and after the use of tebuconazole the average weight of one fruit significantly increased. The obtained results demonstrated that anatomical-morphological and structural-functional rearrangements in tomato plants under the action of exogenous gibberellic acid and tebuconazole occurred against the background of changes in the balance and distribution of endogenous hormones. Increased photosynthetic activity, stimulation of growth processes of some plant organs and inhibition of others increased the biological crop capacity

Planting date, storage and gibberellic acid affect dormancy of Zantedeschia Spreng. hybrids : a thesis presented in partial fulfilment of the requirements for the degree of Masters in Applied Science, Massey University, Palmerston North, New Zealand

To match the supply of Zantedeschia cut flowers and tubers to the demands of the international market, crops have to be timed to a schedule, which requires control of the growth cycle and, in particular, dormancy. In order to improve the predictability and accuracy of timing of Zantedeschia, the effect of different planting seasons and two dormancy-breaking treatments were tested on cultivars 'Black Magic' and 'Treasure', which were known to have a contrasting level of dormancy. Tissue-cultured plants were ex-flasked in July and November 1999, and grown for 180 days in a heated glasshouse (first cycle). Between 120 and 180 days of growth, plants were harvested at 15 days intervals, and tubers cured. Subsequently, tubers were stored for 0 or 3 weeks (10 ± 1°C; 70-80% RH) and dipped in 100 mg.L -1 gibberellic acid plus surfactant or water plus surfactant, prior to planting for dormancy assessment (second cycle). Growing the plants with four months difference in planting date did not cause major alteration in the occurrence of dormancy. Dormancy was brought forward by up to 10 days after the November date of ex-flask, but this was most likely to be due to higher temperatures during that period. In contrast, depth of dormancy varied between cultivars, with 'Black Magic' taking in average 16 days longer to emerge than 'Treasure'. Storage partially released bud dormancy of the tubers. It increased emergence to over 80% regardless of the time of harvest in the first cycle and cultivar, but reduced time to emergence mostly after harvests at 180 days. Furthermore, following storage, time to emergence was reduced to over 50 and 30 days for 'Black Magic' and 'Treasure', respectively, which exceeded the commercially acceptable period to emerge. Gibberellic acid also broke bud dormancy, improving emergence to over 80%, and reduced time to emergence to between 29 and 57 days, irrespective of the time of harvest in the first cycle and cultivar. The effectiveness of gibberellic acid at any time following harvest during the first cycle, may imply that dormancy of Zantedeschia is not as deep as in temperate woody plants. Cessation of leaf emergence in the first cycle was found not to be directly related to the occurrence of dormancy. Degree-days, on the other hand, presented a possible alternative to predict this process. It was estimated that deepest dormancy of 'Black Magic' occurred between 2614 and 2732 °C-days after planting, while deepest dormancy of 'Treasure' occurred between 2681 and 2839 °C-days after planting. The present study presents storage and gibberellic acid as possible options to control dormancy, and the use of degree-days to predict the occurrence of this process. Further research is necessary to develop these options as commercially applicable practices, and to further clarify the process of dormancy in Zantedeschia

Seed germination and in vitro regeneration of the African medicinal and pesticidal plant, Bobgunnia madagascariensis

Propagation of the medicinal and pesticidal tree, Bobgunnia madagascarensis is difficult due to poor and erratic germination of its seeds and slow growth of its seedlings. This study involved two separate experiments. The first evaluated the effect of pre-sowing treatments and growing medium on ex vitro seed germination and early seedling development. The second experiment involved in vitro germination, shoot initiation and rooting of shoots. Pre-sowing seed treatments involved soaking seeds in cold and hot water for 12 and 24 h and soaking in different concentrations (0, 100, 200, 400 and 800 mg/l) of gibberellic acid for 24 h. Soaking of seeds in cold or hot water for up to 24 h did not achieve more than 45% germination, while seeds treated with gibberellic acid achieved 76%) when seeds were sown in a growing medium without compost compared with a medium with compost (<43%). All shoot-tips isolated from the in vitro germinated seedlings on B5 media without plant growth regulators continued to grow as a single shoot, while shoot-tips cultured on B5 supplemented with 0.1 mg/l of naphthaleneacetic acid (NAA) and thidiazuron (TDZ) produced two shoots each after four weeks. It was concluded that B. madagascariensis seeds had very low ex vitro germination percentages. Although, in vitro cultures improved seed germination, axillary shoot multiplication and rooting were not satisfactory. Therefore, further studies are needed to develop an optimal in vitro multiplication protocol for B. madagascariensis

PENGARUH APLIKASI FITOHORMON TERHADAP PERKECAMBAHAN BENIH GAHARU (Gyrinops versteegii) PASCA PROSES PENYIMPANAN

The purpose of this research was to examine the effect of phytohormone and its concentration on germination of 1-week storage G. versteegii’s seeds. Factorial Completely Randomize Design was used with two factors: type of phytohormone (J1:Atonik, J2:gibberellic acid) and phytohormone concentration (K1:200ppm, K2:400ppm). ANOVA shows that phytohormone concentration was the only factor that has a significant difference at α=0.05. Four hundred ppm was an ideal concentration that supports G. versteegii’s seed's better germination rate on atonic and gibberellic acid. However, gibberellic acid has supported a better germination rate than atonic at 400 ppm concentration. It is concluded that gibberellic acid at 400 ppm concentration is the best treatment for G. versteegii germination

The Effects of Gibberellic Acid, Smoke Water, and Cold Stratification on the Germination of Native Perennial Seed

In this study, I evaluated the germination rates of twenty native plant species and their response to cold stratification as well as four chemical solution treatments—water (control), gibberellic acid, smoke water, and gibberellic acid with smoke water. Seeds were evaluated and counted twice a week. Of the twenty evaluated species, sixteen had germination rates over 3% or 1 seed out of 30. Stratification increased germination by 54% when compared to the control. For chemical treatments, gibberellic acid and gibberellic acid with smoke water were significantly different from the control and increased germination by an average of 47% and 48%, respectively. Six species showed a response to chemical treatment and stratification. Four species showed a response to chemical treatments only, and four species showed a response to stratification only. No growth defects were discovered upon further evaluation after sowing the seed. This study suggested that the combination of stratification with smoke water and/or gibberellic acid has a significant effect on the seed germination yield of some native perennials

Seed Germination in Ginkgo biloba L. I. Influences of Cold Treatment, Gibberellic Acid and Red Light

The influences of cold treatment, gibberellic acid and red light treatment on rate of germination of seeds of Ginkgo biloba L. were followed for a 12-wk period. Dispersal units were collected, and the outer fleshy layer was removed soon after harvest. Of water-imbibed, non-cold-treated seeds, 50% of those which germinated did so within 11 wk after planting. A single application of red light accelerated the 50% germination time by 3 wk. Imbibition in GA3 solution did not appear to accelerate germination. With 4-wk cold treatment the 50% germination time was accelerated 6 wk in water-imbibed seeds. Both red light and GA3 treated seeds also were accelerated 6 wk by cold treatment. An 8-wk cold treatment accelerated the 50% germination time 7 wk for all three treatment groups. The influence of red light observed on non-cold-treated seeds was not seen with seeds receiving a cold treatment prior to irradiation. A 12-wk cold treatment period delayed germination in all treated groups. Dry storage of seeds for 4mo at 25 C also delayed germination regardless of red light, GA3 or cold treatment