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1.
Investigations were undertaken to explore the possibility of improving setting, retention and weight of fruits in ‘Early Seedless’ and ‘Calcuttia’ cultivars of lichi (Litchi chinensis) by means of growth regulators. Indole acetic acid (IAA) at 20, 40 and 80 mg l?1, 2,4-dichlorophenoxy acetic acid (2,4-D) at 2,4 and 8 mg l?1 and gibberellic acid (GA3) at 50, 100 and 150 mg l?1 were sprayed on panicles in the first fortnight of April, when 50–100% flowers had opened. All 3 growth regulators caused a favourable effect on fruit setting, fruit retention and weight of individual fruits, but IAA at 20 mg l?1 proved the best for enhancing setting, GA3 at 50 mg l?1 for increasing retention and GA3 at 100 mg l?1 for improving fruit weight. IAA and GA3 should, therefore, be used in combination. Between the 2 cultivars tested, ‘Calcuttia’ proved superior to ‘Early Seedless’ in fruit setting, fruit retention and weight of individual fruits.  相似文献   

2.
Field grown day-neutral, June-bearing and everbearing strawberry cultivars responded similarly to GA3 in most cases. GA3 stimulated daughter-plant production in ‘Hecker’ (DN) and suppressed it in ‘Guardian’ (June). Fifty mg l?1 GA3 increased initial runner production of all cultivars, while both 50 and 100 mg l?1 GA3 increased fruit yield the year following treatment. In greenhouse studies, GA3 initially increased leaf number, petiole length and runner production, but the effects diminished with time. Phthalimide at 1000 mg l?1 was most effective in increasing leaf number.  相似文献   

3.
In order to obtain normal seedlings of peach cultivar ‘Sharbati’ before the commencement of winter, treatments with GA3, thiourea and kinetin were given to seeds before stratification at 7°C, 10°C or 24°C. The seedlings raised from the treated seeds and after-ripened at 24°C were dwarf. The seedling growth was increased when the treated seeds were stratified at 10°C or 7°C and the stratification period was prolonged from 15 days to 75 days. 10°C stratification-temperature was better than 7°C. The seedling growth was improved when the seed coat was removed before the treatments. With respect to both seed types, 1000 mg/l GA3 produced the tallest seedlings at all the after-ripening temperatures and during each stratification period. The next best treatment was 100 mg/l kinetin.  相似文献   

4.
Soaking of bulbs in 3 concentrations of indoleacetic acid (IAA), gibberellic acid (GA3), 2-chloroethyltrimethyl ammonium chloride (cycocel) or 2-chloroethylphosphonic acid (ethrel) showed various responses on growth and flowering. IAA increased the weight and number of bulblets, GA3 increased bulb weight. Cycocel (1000 mg l?1) increased the number of flowers, while GA3 increased the diameter of the flowers.Application of IAA at 100 mg l?1 and GA3 at 10, 100 or 1000 mg l?1 twice as foliar spray at an interval of 30 days promoted the number of bulblets on the treated plants, while high concentrations of cycocel and ethrel (1000 mg l?1) increased the weight of bulblets. All concentrations of IAA, GA3 and 1000 mg l?1 cycocel increased the number and size of the flowers.  相似文献   

5.
Summary

Precocity is particularly important for the economic production of intensively planted apple trees. Unfortunately some cultivars show a propensity for barewood on young trees, which limits early production on 2 year-old spur sites. The new cultivar, ‘Scifresh’ (Jazz?) has shown serious problems of barewood under New Zealand conditions on M.9 and M.26 rootstocks. Barewood has been associated with excessive flowering on feathers and 1 year-old wood. Weak flower clusters develop towards the base of the shoots which do not set fruit and drop off, leaving blind buds. Although there are larger, more well-developed flower clusters on the distal parts of the 1 year-old shoots, cropping these can result in spur extinction. Therefore, in both cases, there is a lack of spur development for the following season resulting in barewood. Experimental treatments have focused on: 1) the effect of timing (January-May) and concentration (400 and 133 mg l–1 gibberellic acid GA3) sprays in the nursery to reduce flowering on 1 year-old wood; and 2) the effect of concentration and timing of localised cytokinin applications in the Spring to re-invigorate blind buds. Two applications of 400 mg l–1 GA3 in late January and late February in the first year in the nursery were effective in eliminating flowering on “knip boom” trees in the following Spring after cutting back. Two applications of 400 mg l–1 GA3, in early and late January, to “knip boom” trees in their second year in the nursery reduced flowering by over 40% when the trees were planted in the orchard. Twelve months later these trees showed an increased density of spur flowers on the original feathers. Aqueous solutions of the cytokinins benzyladenine and thidiazuron, at 500 mg l–1 or 2500 mg l–1 respectively, were applied by brush, prior to, during and post-budbreak, to sections of barewood on 2 year-old or 3 year-old wood on main branches of ‘Scifresh’/M.9 trees. Thidiazuron (at 2500 mg l–1) was far more effective than benzyladenine at inducing growth of dormant buds, even resulting in multiple bud-breaks at individual sites.  相似文献   

6.
《Scientia Horticulturae》1986,28(4):323-329
Sambucus caerulea (elder) seeds did not germinate after 4°C cool treatments for up to 30 days, when monitored for a further 30 days at 21°C. When seeds were soaked for 24 h in gibberellic acid (GA3) prior to and during cold treatment, germination percentage depended on GA3 concentration and duration of cold treatment. The highest germination percentage was 55 (1000 mg l−1 GA3 for 30 days at 4°C). When seeds were treated with ethephon at 0, 100 or 1000 mg l−1, no germination was recorded after a subsequent 30-day 4°C treatment. Ethephon added to GA3 gave a strong interaction, leading to further promotion in germination. Optimal germination was obtained after 1000 mg l−1 GA3 and 100 mg l−1 ethephon for 30 days at 4°C (69%).The addition of ethanol, acetone, dimethyl sulfoxide or polyethylene glycol to the GA3 soak as infusion agents either reduced or did not change the germination percentage.  相似文献   

7.
Application of 2,4-D and 2,4,5-T at concentrations ranging from 5 to 20 mg l?1 to 5-year-old ‘Pant Lemon-1’ (Citrus limon Burm) trees reduced the vegetative growth in terms of height, spread, shoot length, number and size of the leaves in the autumn flush. Various NAA treatments (5–20 mg l?1), however, enhanced growth, but not to the extent that was observed after GA3 treatments. Application of GA3 at 10–40 mg l?1 significantly enhanced all aspects of growth, and the effects were most pronounced at 20 and 40 mg l?1. Nutritional status of the leaves showed a slight variation in relation to vegetative growth under various treatments.Some 2,4-D- and 2,4,5-T-treatments increased the fruit yield over the control, which could suggest mobilization of foods even at the expense of reduced vegetative growth. On the other hand, NAA, particularly at 10 mg l?1, increased both vegetative growth and yield, suggesting that the transport of the photosynthates from the leaves to the fruits was not at the expense of new growth extension. Due to excessive growth enhancement under higher concentrations of GA3 (20 and 40 mg l?1), comparatively fewer nutrients were translocated to the fruit “sinks”, thereby resulting in a non-significant decrease in yield.  相似文献   

8.
Summary

Different concentrations of aminoethoxyvinylglycine (AVG) and gibberellic acid (GA3) and their combinations, applied at two stages of fruit growth, were evaluated for prolonging the marketing season of `Feicheng' peaches. GA3 applied at the end of pit hardening, or AVG applied two weeks before commercial harvest, inhibited fruit maturation on the tree, delayed harvest and reduced flesh browning after cold storage in a concentration-dependent manner. A synergistic effect was found when both GA3 and AVG were used, with the combination of 100 or 150.mg l±1 GA3, applied at the end of pit hardening, and 100 mg l±1 AVG, applied two weeks before harvest giving the best results. These combinations retarded the change in ground colour, loss of firmness, and reduction in acidity by 2±3 weeks. Since harvest was prolonged by 2±3 weeks, soluble solids content (SSC) in fruit increased compared with the control (harvested earlier). Fruit size was significantly greater on treated trees compared with the controls when fruit set was controlled to the same level by hand thinning. After four weeks of storage and 4.d at 208C, 83% of control fruit developed tissue browning, but only 5% of AVG + GA3-treated fruit developed browning after six weeks of storage and 4 d at 208C. Thus, the marketing season of `Feicheng' peaches was prolonged by at least four weeks by 100 or 150 mg l±1 of GA3 and 100 mg l±1 of AVG. Fruit treated with 150 mg l±1 GA3 plus 100 to 150 mg l±1 AVG showed similar results but failed to ripen properly after cold storage.  相似文献   

9.
Qualities of Indian gooseberry fruits (Phyllanthus emblica L.) were determined after dip-treatment with wax emulsion (WE) with or without morphactin (Mor) and gibberellic acid (GA3). Dip-treatments with 100–500 mg l?1 Mor reduced marketability by inducing browning and high weight loss, but loss in ascorbic acid was checked and phenols increased. 10 mg l?1 Mor maintained marketability at par with control, effectively controlled loss in ascorbic acid, and increased acidity and reducing sugars. GA3, although failing to control the loss of ascorbic acid, was effective in checking browning and thereby increased the market value of fruits as compared with controls and Mor-treated fruits.WE with or without Mor (10 mg l?1) controlled browning, accumulation of phenols and losses in weight and moisture as compared with 10 mg l?1 Mor, 100 mg l?1 GA3, or control, but could not retain ascorbic acid in comparison to 10 mg l?1 Mor-treated fruits. Marketability of fruits having had treatment with either WE or GA3 was the same. Fruits having had combined treatment with WE and 10 mg l?1 Mor had maximum marketability. Minimum marketability was observed in fruits subjected to a combined treatment of WE + 100 mg l?1 GA3 due to maximum infection with Aspergillus spp. and Penicillium spp.  相似文献   

10.
Summary

Poor pollen quality and germination capacity curtails early yield in strawberry. The aim of this study was to establish a reliable method for in vitro assessment of strawberry pollen germination ability and to investigate further the effects of photoperiod and gibberellin on pollen germination and quality. In the first part of the study, pollen from seven strawberry cultivars (Chandler, Selva, Tudla, Camarosa, Eris, Pajaro and Irvine) was collected and its germination capacity and incidence of deformed pollen grains assessed in vitro using the hanging-drop technique. Highest germination rates, in ‘Selva’, were observed in a nutrient medium of 10% sucrose. Addition of calcium nitrate to the medium decreased the germination percentages of all cultivars. There was no significant difference, on average, between the germination rate at 20° and 25°C. Genetic factors affected the incidence of deformed pollen grains significantly, with ‘Pajaro’ showing the highest percentage (76%). In the second part, groups of young strawberry plants, cultivar Seascape, grown either under natural early spring conditions or under long-day or short-day conditions were sprayed once with GA3 at 0, 50, or 200 mg l–1. Pollen germination and deformation and stamen length were assessed three months later. In plants of the first group, GA3 at 50 mg l–1 increased pollen germination and decreased the incidence of deformed pollen grains, while GA3 at 200 mg l–1 decreased pollen germination without affecting the formation of deformed pollen grains. Plants of the second group showed a higher rate of pollen germination under long than under short days. GA3 at 200 mg l–1 decreased pollen germination under either short- or long-day conditions compared with the controls but doubled the percentage of deformed pollen only under short days. Stamens in control plants grew four times as long under long- than short-day conditions. GA3 did not affect stamen length under long days but significantly enhanced their growth under short days.  相似文献   

11.
《Scientia Horticulturae》2005,106(3):415-426
The effect of silver nitrate on shoot differentiation and shoot growth was examined in order to improve the regeneration efficiency of pistachio (Pistacia vera L. cv. Kirmizi) in vitro. Nodal explants of in vitro-grown seedlings were used to test various concentrations and combinations of 6-benzyladenine (BA), kinetin (KIN), gibberellic acid (GA3) and silver nitrate (AgNO3). Addition of AgNO3 up to 48.0 μM to the culture medium improved the regeneration frequency and shoot growth, and reduced basal callus formation in all regenerated explants. The highest regeneration frequency (100%) was recorded on Murashige and Skoog (MS) medium containing 9.0 μM BA, 0.2 μM GA3 and 24.0 or 48.0 μM AgNO3 in combination. The best proliferation response in terms of both shoot formation and low callus production was obtained in the medium containing a combination of 9.0 μM BA, 0.2 μM GA3 and 12.0 μM AgNO3. Regenerated shoots, coming from three cycles of subculturing in proliferation media, were rooted in half-strength MS medium containing 12.0 μM indole-3-butyric acid (IBA). Well rooted plantlets were acclimatized and eventually established in peat and perlite. The development and optimization of an effective micropropagation protocol that is presented in this paper can give an important contribution to improve the quality of pistachio plants and, as a consequence, of orchard production in Middle East countries.  相似文献   

12.
Summary

Simple Sequence Repeat (SSR) and Sequence-Related Amplified Polymorphism (SRAP) molecular marker systems were used to analyse four commercially important pistachio rootstocks: two species of Pistacia atlantica (cv. ‘Standard Atlantica’), P. integerrima (cv. ‘Pioneer Gold’) and two interspecific hybrids of the same, ‘Pioneer Gold II’ (‘PGII’) and ‘University of California at Berkeley 1’ (‘UCB-1’). A total of 35 putative alleles were detected by 12 SSR primer pairs with an average of 2.9 alleles per locus. The number of putative alleles ranged from 2 to 5 in the pistachio rootstocks tested. The number of bands produced by the SRAP protocol was highly variable, ranging from 11 to 38, with an average of 25.2 per primer combination. Eight primer combinations resulted in 104 (51%) polymorphic markers in these samples. SSR and SRAP markers successfully identified all pistachio rootstocks tested from their unique fingerprints. Both SSR and SRAP molecular markers confirmed that the observed variation in ‘UCB-1’ rootstock is genetic.Thus, there will always be variation among ‘UCB-1’ hybrid seedling progeny due to the segregation of alleles when propagated by seed.We also found evidence of contaminating pollen other than from P. integerrima in some hybrid ‘UCB-1’ rootstock progeny produced by closed pollination. Only alleles from the cultivar ‘Standard Atlantica’ were observed in abnormal ‘UCB-1’ rootstock in the nursery. We found that the poor performance of the scion cv. ‘Kerman’ on ‘UCB-1’ rootstock was not due to ‘UCB-1' rootstocks displaying abnormal behaviour in the nursery. We have successfully developed two efficient marker systems for genome analyses in pistachio, which can be used for identification and management in pistachio rootstock production.  相似文献   

13.
The effect of GA3 15 mg l?1, Planofix (NAA = 1-naphthalene acetic acid) 300 mg l?1 and Ethrel 250 mg l?1 on granulation and fruit quality in ‘Kaula’ mandarin (Citrus recticulata Blanco) was studied during 1975–1976. Three sprays of Planofix reduced the incidence of granulation to 30.7% from 62.7% in control. Three sprays of GA3 were almost equally effective (31.3% granulation). These treatments also improved the fruit quality and gave the highest fruit weight, pulp percentage, juice, T.S.S., reducing and non-reducing sugars and ascorbic acid, and the lowest acidity, peel and rag. In both these treatments (3 sprays of GA3 or Planofix) the T.S.S. was 9.3% (8.1% in control). The application of 3 sprays of Planofix 300 mg l?1 or GA3 15 mg l?1 is, therefore, considered to be successful in reducing the granulation in this cultivar of mandarin.  相似文献   

14.
‘Alaska’ and ‘Redwing’ azaleas having dormant flower buds were sprayed with gibberellins (GA3 or GA4 + 7) alone and in combination with thiourea, N6 benzyl adenine (BA) or kinetin weekly for 3 or 4 weeks to test the efficacy of these materials in breaking bud dormancy. Additional plants received 6 weeks of cold storage at 4.5°C or glasshouse day temperatures of 21°C and above. The 2000 and 3000 mg l?1 GA3 and Ga4 + 7 sprays were better than 1000 mg l?1 in promoting flowering, with ‘Redwing’ responding better than ‘Alaska’. GA-treated plants flowered in fewer days than those receiving cold storage. Flower diameter and pedicel length increased with higher levels of GA, and flower uniformity was comparable to cold-stored plants on most GA-treated ‘Redwing’-plants. Thiourea, BA and kinetin applied alone had no effect and considerable cytokinin activity was highest in GA-treated buds 14–21 days after treatment application. No increase in activity occurred on plants not receiving GA.  相似文献   

15.
Summary

The effects of a post-harvest application of gibberellic acid (GA3) at various concentrations (0, 10, 25, 50, or 100 mg l–1) and for different periods of incubation (1, 2, or 3 h) on the breaking of dormancy and on sprouting in potato (Solanum tuberosum L., cv. Marfona) minitubers of two ages (freshly-harvested or 1 week after harvest) were investigated. Compared with untreated, control minitubers, GA3-treated minitubers showed a significantly shorter period of dormancy (46 d), especially when the minitubers were treated at all concentrations immediately after harvest (41 d). GA3 treatment had a greater effect on dormancy in freshly-harvested minitubers than in 1 week-old minitubers, probably because of the reduced uptake of GA3 solution after skin-set. At lower concentrations of GA3, the period of dormancy tended to decrease the longer the minitubers were immersed in the GA3 solution. In contrast, at higher concentrations of GA3, the duration of immersion only had an effect up to 2 h and any longer immersion was ineffective. The average number of sprouts was not affected by GA3 concentration, or by the time of incubation, but was significantly higher for freshly-harvested minitubers (1.4) than for 1 week-old minitubers (1.2). The lengths of the sprouts increased with an increase in GA3 concentration, especially in freshly-harvested minitubers. Consequently, immersing freshly-harvested potato minitubers in a low concentration of GA3 (up to 25 mg l–1) for up to 3 h effectively shortened the period of dormancy and led to the formation of sprouts of optimum length.  相似文献   

16.
Summary

Experiments were conducted to determine the effects of 50 mg l–1 and 100 mg l–1 indole-3-butyric acid (IBA), each of three strains of non-pathogenic Agrobacterium rubi (A1, A16 and A18), a non-pathogenic strain of Bacillus subtilis (OSU-142), and radicle tip-cutting (RC) alone, or a combination of bacteria and RC on the number of lateral roots, plant height, stem diameter, root length, and fresh and dry root weights of Pistacia vera seedlings. Treatment of germinated seeds of P. vera with IBA, bacteria, RC, or bacteria plus RC, caused significant increases in lateral root formation in seedlings. Treatments with 50 mg l–1 and 100 mg l–1 IBA, RC, A. rubi A1, A16, A18, B. subtilis OSU 142, RC+A1, RC+A16, RC+A18 or RC+OSU-142 increased average lateral root numbers from 2.1 in untreated controls, to 8.4, 10.3, 5.3, 7.8, 6.9, 6.2, 5.4, 8.1, 7.8, 5.9 and 5.4, respectively. IBA (100 mg l–1) gave the highest number of lateral roots. Agrobacterium rubi strain A1 was found to be more effective than the other bacterial strains, RC or control treatments in increasing the numbers of lateral roots.  相似文献   

17.
Summary

Micropropagation of Darjeeling orange (Darjeeling mandarin) was done by shoot-tip grafting on the local rootstocks rough lemon, sour orange and Rangpur lime. Seedlings of these plants were raised in MS medium in standard conditions of temperature, light duration and plant age. Microbuds (0.2 mm long), aseptically excised from the scion, were grafted onto the decapitated rootstock seedlings. The micrografts in culture medium were grown under standard lighting. Rootstock seedlings showed optimum growth at 25–30°C. Optimum growth of the micrografts resulted from treatment in complete darkness for 4 d after grafting followed by exposure to 750 W for 16 h d?1 for 15 d and 1500–2000 W for 16 h d?1 for 39 d. The success of micrografting depended on the age of the rootstock seedling which was 21 d, 14 d and 14 d for sour orange, rough lemon and Rangpur lime respectively. The micrografts were then double grafted to the two year old rootstocks seedlings of the respective species and the age of the micrografts for the successful double grafts was also standardized. The survival rate was high with 40 d, 45 d and 45 d micrografts on sour orange, rough lemon and Rangpur lime respectively. The double-grafts were then indexed for tristeza virus and greening disease after six months’ growth in an insect-proof screenhouse and found to be free from these graft transmissible diseases.  相似文献   

18.
In attempts to reduce the glasshouse period of fully-cooled 5°C-forced tulips, ‘Apeldoorn’ bulbs were soaked before planting in aerated and non-aerated gibberellic acid (GA3) solutions for 2–48 h. A 48-h treatment with 250–500 mg l?1 GA3 was the most effective, giving a glasshouse period 7–11 days shorter than for untreated bulbs. Soaks for 24 and 48 h caused root emergence, and 48-h soaks caused perianth segment splitting in one experiment. Aerated or non-aerated GA3 solutions gave similar results. Soaking in water alone gave a smaller increase in earliness. In general, a shortened glasshouse period was associated with shorter whole stem and last internode lengths. In GA3 treatments, flower losses were lower than for distilled water treated and untreated bulbs. A practical treatment would be a non-aerated soak for 24 h with between 250 and 500 mg l?1 GA3.  相似文献   

19.
低温与赤霉素处理对‘凤丹’种子萌发和幼苗生长的影响   总被引：1，自引：0，他引：1  
成仿云  杜秀娟 《园艺学报》2008,35(4):553-558
研究了在容器栽培条件下,赤霉素(GA3)与低温处理对促进‘凤丹’牡丹种子生根、萌芽和幼苗生长的效果,结果表明：GA3能够促进种子生根,100～200 mg﹒L-1低浓度处理有利于提高生根率与生根质量;在一定范围内,延长低温处理时间促进种子萌发和幼苗生长;在低温足以打破上胚轴休眠时,较高浓度的GA3对幼苗生长发育不利。综合分析不同处理对发芽率、发芽指数、苗高、叶片数、第1叶叶宽、茎长以及地上和地下部干质量等指标的影响,发现21 d和28 d低温分别结合100或200 mg﹒L-1 GA3处理,最有利于种子萌发和幼苗生长。  相似文献   

20.
The present studies were undertaken with a view to standardize the medium and culture conditions for embryo culture of five cultivars of walnut viz., ACO 38853, Netar Akhrot, Gobind, Solding Selection and Blackmore. Embryos from mature fruits were aseptically excised and cultured on MS medium supplemented with different combinations of BAP, kinetin and GA3. Best performing medium was MS with 0.5 mg l−1 kinetin, 0.5 mg l−1 BAP and 2 mg l−1 GA3 yielding 66.6% germination in Netar Akhrot after 12 days of culturing. Percent germination of excised embryos was higher when GA3 and cold treatments were simultaneously applied as compared to those when applied separately. Netar Akhrot was found to be the best responding cultivar, which had a range of 25–66.6% embryo germination under different culture conditions. Plantlets with shoots and roots have been obtained in Netar Akhrot and ACO38853 and are transferred to soil after hardening.  相似文献   

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