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1.
The plant growth regulator CycocelTM [(2-chloroethyl)trimethylammonium chloride] can be used to produce drought tolerance in grapevine (Vitis vinifera L.) due to a reduction in the ratio between vegetative growth and fruit production. To evaluate the physiological responses of two grapevine cultivars to drought and CycocelTM treatment, a factorial experiment was conducted in a greenhouse. The factors included irrigation frequency (at 5-, 10-, or 15-day intervals corresponding to no, mild, or severe drought stress), CycocelTM concentration (0, 500, or 1000 mg l–1), and cultivar (‘Rasheh’ or ‘Bidane-Sefid’). Stomatal conductance (gs) the net rate of CO2 assimilation (Anet), the rate of transpiration (Tr), and chlorophyll a and b concentrations decreased in plants exposed to mild or severe water-deficit stress, whereas carotenoid, proline, and total soluble sugar concentrations increased compared to plants with no drought stress. The relative water content (RWC) of leaves declined only under severe drought stress. A reduction in intercellular CO2 concentrations (Ci) occurred under mild drought stress; however, under severe drought stress, Ci values increased. Under mild drought stress, the reduction in the net rate of photosynthesis was related to stomatal closure, whereas under severe drought stress, non-stomatal factors were dominant. Water-use efficiency (WUE) improved under mild drought stress relative to non-stressed plants, but under severe drought, it declined. Foliar applications of CycocelTM resulted in increased Anet, gs, Tr, and WUE values, as well as proline and soluble sugar concentrations. ‘Rasheh’ was more tolerant to drought stress than was ‘Bidane-Sefid’. Foliar applications of CycocelTM, particularly at 1000 mg l–1, mitigated the negative effects of drought stress by increasing Anet, WUE, RWC, compatible solute concentrations, such as proline, soluble sugar, and chlorophyll a and b concentrations.  相似文献   

2.
Shedding of the upper parts of unlignified grapevine (Vitis vinifera L.) canes is frequent during autumn. Stress conditions during the growing-season lead to similar shedding of shoot tips. The separation process occurs above a node in the boundary area between the distal part of the diaphragm and the pith.Ethephon (2-chloroethyl-phosphonic acid) sprays, at 750 or 1500 mg l?1, induced separation of the shoot tips of ‘Perlette’ and ‘Queen of the Vineyards’. Ethylene (C2H4) 200 vpm and ethephon at 10, 100 and 1000 mg l?1 enhanced separation in shoot explants, whereas 2,4,5-TP (2,4,5-trichlorophenoxy-propionic acid) at concentrations above 1 mg l?1 arrested it.This phenomenon may be regarded as a shoot abscission process which may represent adaptation of self-pruning of the grapevine.  相似文献   

3.
《Scientia Horticulturae》1986,28(4):355-368
Foliar sprays of Promalin (gibberellins A4 + 7 + 6-benzylamino purine) applied to 1-year-old apple (Malus domestica Borkh.) trees at the 3–5-cm growth stage significantly increased lateral branching in 5 of 9 cultivars tested. Branching response ranged from 0% (‘Winter Banana’) to 131% (‘Starkrimson Delicious’) of the untreated controls. Total shoot growth was not consistently increased by 6-benzylamino purine or Promalin in tests over 3 years on spur and non-spur 1- and 2-year-old apple trees. Sprays of 50–300 mg l−1 Promalin were ineffective for increased branch development. Sprays of 300–500 mg l−1 increased total shoot numbers and reduced average shoot length. Sprays applied prior to new terminal growth in spring were ineffective. Treatment during periods of active shoot growth were generally effective, but periods of stress may have reduced response. Sprays were more effective for inducing lateral shoot formation than dormant heading or delayed dormant heading (pruning) (10 days after full bloom) in ‘Criterion Golden Delicious’. No difference in branching response was observed between BA and Promalin. Addition of a spray adjuvant (Buffer-X) did not affect branching response. Repeat annual single sprays of Promalin applied to dormant pruned trees were generally less effective for stimulating lateral branching than a single application in a given year. Phytotoxicity was associated with Promalin sprays at 300–500 mg l−1 on ‘Delicious’.  相似文献   

4.
Subject Index     
《Scientia Horticulturae》2005,103(4):515-525
Prohexadione-calcium (ProCa) is a gibberellin biosynthesis inhibitor with limited persistence and low toxicity that has recently been registered as a shoot growth retardant for apples in North America (Apogee®) and Europe (Regalis®). We investigated the response of six different pear cultivars (‘Rosemarie’, ‘Forelle’, ‘Packham's Triumph’, ‘Flamingo’, ‘Early Bon Chretien’ and ‘Golden Russet Bosc’) to ProCa in the Western Cape, South Africa, over the period 1999–2003. ProCa treatments ranging from 50 to 250 mg l−1 were applied between one and three times per season and were compared with girdling and control treatments. ProCa application reduced shoot growth in all of the cultivars. ‘Forelle’, was least responsive and showed a reduction in 2002/2003 but not 2001/2002. ‘Rosemarie’, ‘Flamingo’, ‘Packham's Triumph’ and ‘Golden Russet Bosc’ were most responsive, with shoot growth being reduced by up to 50% of the control for the latter two cultivars. The response to number of applications and ProCa concentration was not consistent across cultivars. ‘Early Bon Chretien’, for example, only responded to high ProCa concentration, whereas ‘Rosemarie’ was very responsive at the lowest ProCa concentration. ProCa application improved fruit set but decreased final fruit size in some of the cultivars, particularly in ‘Rosemarie’. It also caused a decrease in return bloom in ‘Forelle’ and ‘Packham's Triumph’. The response of different cultivars to girdling, in terms of shoot growth and fruit set was highly variable. Girdling tended to increase final fruit size and return bloom. ProCa shows potential as a shoot growth retardant for the pear cultivars investigated, but the response of reduced fruit size in some cultivars requires mitigation. Future research on combined girdling and ProCa treatments may be instructive.  相似文献   

5.
The effects of N and Ca nutrition on plant growth and shoot elemental content of Petunia × hybrida Hort. Vilm. - Andr. ‘Coral Sea’ were evaluated. Nitrogen and Ca were applied separately or in combination in three experiments: (1) N at 0, 100, 200 or 400 mg l?1; (2) Ca at 0, 75, 150 or 300 mg l?1; (3) N at 0 or 100 mg l?1 and Ca at 0 or 150 mg l?1 combined factorially. Shoot and root dry weights, branch length and flower number were highest when plants received 100 mg l?1 N. Plants treated with 150 mg l?1 Ca had the highest shoot and root dry weights. Branch length was maximal at 300 mg l?1 Ca.Nitrogen and Ca interacted to increase shoot dry weights, branch number and length, leaf area and flower number. Increasing N concentrations increased N and decreased P, Mn and Zn shoot contents. Calcium content of shoots increased while N, P and Mg decreased in response to increasing applications of Ca to petunia plants. Minimal N and Ca tissue concentrations for optimal P. × hybrida growth were 3.3 and 0.67%, respectively.  相似文献   

6.
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   

7.
Summary

Cloudy juices from six apple cultivars from Poland (‘Ariwa’, ‘Gold Milenium’, ‘Florina’, ‘Melfree’, ‘Novamac’, and ‘Rajka’) and four French cultivars (‘Ariane’, ‘Chanteline’, ‘Judeline’, and ‘Judor’) were produced and chemically characterised. The analyses encompassed 23 chemical parameters and phenolics profiles. The most important parameter, differentiating cloudy juice from clear juice, was turbidity. Cloudy juices were characterised by having an average total turbidity of 1,210 Nephelometric Turbidity Units (NTU) and a stability of turbidity of 42%. Some of the results deviated from the accepted ranges given in reference values for apple juices in the Code of Practice of the European Fruit Juice Association. This occurred in the cases of simple sugars and saccharose contents of the Polish apple juices (e.g., up to 56.9 mg l–1 of saccharose vs. a maximum value of 30 mg l?1), and for some mineral compounds in the French apple juices (e.g., sodium values up to 10 mg l?1). Large variations were found in case of important healthconferring components. Water-soluble pectin contents varied from 205 mg l?1 for ‘Chanteline’, to 1,289 mg l?1 for ‘Gold Milenium’; while, in the case of phenolic compounds, the range was from 85.7 mg l?1 for ‘Novamac’, to 524.8 mg l?1 for ‘Melfree’.  相似文献   

8.
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   

9.
王微 《北方园艺》2011,(23):57-60
通过对结缕草在土壤干旱及复水过程中叶片相对含水量(RWC)、游离脯氨酸含量(Pro)、叶绿素含量、超氧化物歧化酶(SOD)活性、丙二醛(MDA)含量、可溶性糖(TSC)含量等生理指标的测定,研究土壤干旱对结缕草生理特性的影响.结果表明:干旱胁迫引起结缕草的叶片相对含水量明显下降,游离脯氨酸含量、丙二醛含量及可溶性糖含量均随干旱天数的增加呈持续增加的趋势,而叶绿素含量和SOD酶活性先增后减.复水后各项生理指标除相对含水量、游离脯氨酸含量外均随着复水时间的增加逐渐恢复至对照水平.干旱胁迫下,结缕草水分平衡的保持、SOD酶活性及丙二醛含量的增加以及脯氨酸和可溶性糖等渗透调节物质的积累,是结缕草抗旱的重要生理机制.  相似文献   

10.
The effect of post-harvest application of methyl jasmonate (MeJ) on reactive oxygen species, antioxidant systems, and cellular structure in Chinese winter jujube (Ziziphus Jujuba Mill.) at the major ripening stages of green maturity (GM) and half-red maturity (HM) were investigated. Jujube fruit at each ripening stage were treated with 0, 50, 100, and 200?μmol?l?1 MeJ for 24 h, then stored at 20 ± 2°C for shelf-life testing. Thereafter, changes in firmness, color, respiration rate, superoxide anion (O2?), hydrogen peroxide (H2O2), malondialdehyde (MDA), superoxide dismutase (SOD), catalase (CAT), ascorbic acid (AsA), and glutathione (GSH) were measured at 4-d intervals for up to 8 d. Results showed that, in comparison with control fruit, MeJ treatment effectively suppressed the decrease of firmness, color, and respiration rate, inhibited the production of O2? and accumulation of H2O2 and MDA, maintained higher activities of SOD and CAT and contents of AsA and GSH, and preserved the integrity of cell membranes and organelles. The degree of maturity influenced the benefits of MeJ application. The 100?μmol?l?1 MeJ treatment had a positive impact on antioxidant systems for GM fruit, whereas a MeJ concentration below 100 μmol l?1 was found to extend the shelf life of HM fruit.  相似文献   

11.
Greenhouse-grown ‘Ives’ and ‘Delaware’ grapevines (Vitis labruscana, Bailey) were fumigated for 4-hours with ozone (O3) and/or sulfur dioxide (SO2) at 0.40 and 0.80 mg l?1. Fumigations were performed in a plexiglass chamber situated within a controlled environment walk-in growth chamber. When applied separately, both gases induced characteristic foliar injury. ‘Ives’ grapevines were much more sensitive to O3SO2 fumigations than were ‘Delaware’ grapevines. Within each cultivar, leaf necrosis and shoot growth reduction were greatest following fumigation with 0.80 mg l?1 O3 plus 0.80 mg l?1 SO2. Leaf abscission occurred only on ‘Ives’ and was related to foliar necrosis. Shoot growth following fumigation was less on vines having most foliar necrosis. Yet, ‘Delaware’ vines showing less than 1% leaf area necrosis still had significant reductions in shoot growth. All O3 and SO2 fumigations resulted in stomatal opening.  相似文献   

12.
 测定了土壤干旱条件下矮生狗牙根、沟叶结缕草和地毯草相对含水量和相对电导率的变化。结果表明，矮生狗牙根的耐旱性较强，沟叶结缕草次之，而地毯草对干旱敏感。干旱胁迫下，地毯草积累脯氨酸最多，沟叶结缕草次之，矮生狗牙根最少，草坪草的脯氨酸的积累与耐旱性呈负相关。地毯草超氧化物歧化酶(SOD)活性持续升高，过氧化氢酶(CAT)活性在短暂升高后降低，过氧化物酶(POD)活性降低；矮生狗牙根和沟叶结缕草的SOD活性先升后降，CAT和POD活性则维持较高水平，表明草坪草的耐旱性与抗氧化酶活性有关。  相似文献   

13.
A greenhouse experiment was carried out to determine the growth, photosynthetic activity, and mineral composition in two ornamental shrubs [Viburnum lucidum L. (arrow-wood) and Callistemon citrinus (Curtis) Stapf. (red bottlebrush)] that had been treated or not treated with 2.5 mM glycine betaine (GB) or 5.0 mM proline (Pro). Plants were supplied with a non-salinised or salinised nutrient solution containing 200 mM NaCl. Salinity caused reductions in plant growth parameters, shoot biomass production, and net CO2 assimilation in both species. Neither Pro nor GB were able to mitigate the adverse effects of salinity in bottlebrush, whereas GB reduced the deleterious effects of salt stress on arrow-wood, indicating a differential species-specific response to these osmolytes. The application of GB to salt-stressed arrow-wood increased apical and lateral shoot lengths, the number of leaves per plant, and shoot dry biomass by 222%, 113%, 238%, and 49%, respectively, compared to untreated or Pro-treated plants. The improved performance of salt-stressed arrow-wood plants whose roots were treated with 2.5 mM GB was attributed to partial suppression of Na uptake, higher chlorophyll concentrations, and the better nutritional status (higher K) of shoots.  相似文献   

14.
CPPU application on size and quality of hardy kiwifruit   总被引：1，自引：0，他引：1  
For the purpose of determining the appropriate conditions of application to increase the size of a hardy kiwifruit, Actinidia arguta ‘Mitsuko’, N1-(2-chloro-4-pyridyl)-N3-phenylurea (CPPU) was applied at three different growth stages of the crop: at petal fall, 10 and 25 days after petal fall (DAPF), and three different concentrations: 1, 5 and 10 mg l−1. A significant increase in fruit size was obtained by treatment at the concentrations of 5–10 mg l−1 and at 10 DAPF. The fruit weight doubled. Although a significant reduction in the concentrations of total soluble solids (TSS), titratable acids (TA) and ascorbic acid (AsA) in the CPPU-treated fruits was recorded, the TSS/TA ratio and AsA content per fruit increased by the treatment. CPPU application at petal fall induced abnormally protruding fruit tip.  相似文献   

15.
Cold stress is one of the most detrimental environmental factors affecting plant growth and development. Melatonin (MEL), a natural indoleamine compound, responds to various environmental cues. To explore the role of MEL in the response of melon (Cucumis melo L.) seedlings to cold stress, the effects of exogenous MEL on the ascorbate–glutathione (AsA–GSH) cycle and proline metabolism were investigated. Melon seedlings were sprayed with various concentrations of MEL (0, 50, 100, 200, or 400 μM), then exposed to cold stress, 12/6°C (day/night) for 7 d, followed by recovery at 28/18°C for another 7 d. The results showed that MEL, especially the 200 μM treatment, dramatically alleviated growth inhibition caused by cold stress, manifested by increased plant growth and decreased O2?¯ production rate and malondialdehyde content. Importantly, exogenous application of MEL enhanced the ratios of reduced and oxidized forms of AsA (AsA/DHA) and GSH (GSH/GSSG), and the activities of ascorbate peroxidase (APX), glutathione reductase (GR), and dehydroascorbate reductase (DHAR) involved in the ascorbate–glutathione (AsA–GSH) cycle in melon seedings grown under cold stress. Besides, MEL pretreatment further increased the contents of proline and soluble protein under cold stress. The results reveal that protective effects of MEL against cold stress in melon seedlings are most likely associated with the regulation of the AsA–GSH cycle and proline metabolism as an effective antioxidant system.  相似文献   

16.
Summary

Beneh (Pistacia mutica F. & M.) and kolkhong (Pistacia khinjuk Stock) are wild species of pistachio which grow naturally with other trees in some parts of Iran. Because of their adaptibility to severe environmental conditions and their resistance to some pests and diseases, they can be used as rootstocks for pistachio cultivars. Poor germination and very low seedling vigour of these two species have been a major problem in using them as rootstocks for pistachio cultivars. In this study gibberellic acid (GA3), at five concentrations (100, 250, 500, 750 and 1000 mg l21), were used during and after stratification to enhance seedling growth. The results showed that GA3, applied during and after stratification, significantly increased the length, trunk diameter, internode length, leaf area and fresh and dry weight of seedlings of both beneh and kolkhong species. However, application of GA3 after stratification was more effective on seedling growth of beneh. GA3 applied at higher concentrations (500 and 750 mg l21) increased the rate of growth, but growth malformations were clearly evident in seedlings of kolkhong. GA3 at 250 mg l21 enhanced seedlings growth of kolkhong. It was concluded that application of GA3 to the seedlings might be a useful method for promoting rapid shoot growth of beneh and kolkhong and reduce the expense of seedling production in glasshouse conditions.  相似文献   

17.
Summary

Core browning often occurs as a physiological disorder in ‘Yali’ pear (Pyrus bretschneideri Rehd.) and results in a high losses during storage. In this study, the effects of fumigation with nitric oxide (NO) gas on the incidence of core browning in ‘Yali’ pears during cold storage were investigated. ‘Yali’ pear fruit were treated with 0, 10, 20, or 30 µl l–1 NO at 25º ± 2ºC for 3 h under anaerobic conditions, then stored at 0º ± 1ºC under normal air for up to 120 d. The data showed that fumigation with 20 µl l–1 NO was most effective at suppressing core browning. Thereafter, treatment with 20 µl l–1 NO was used for comparisons with untreated control fruit in experiments to measure changes in total phenolics contents, polyphenol oxidase (PPO) activities, and the contents of glutathione (GSH), ascorbic acid (AsA), and NO in fruit core tissue during storage. The results showed that NO-fumigated fruit had lower PPO activity, but higher GSH and AsA contents in their core tissue compared with untreated control fruit. NO fumigation also maintained higher endogenous NO levels in core tissue after 60 d in storage, while the total phenolics contents of fruit remained at lower levels until day-100 of storage. These results indicate that the inhibitory effect of fumigation with

20 µl l–1 NO on core browning was associated with its effects on reducing PPO activity and total phenolics contents, while maintaining the contents of GSH and AsA in core tissue of ‘Yali’ pear during cold storage.  相似文献   

18.
Micropropagation of 12 raspberry seedling selections and the cultivar ‘Malling Jewel’ has been achieved. A basic culture medium (Linsmaier and Skoog, 1965) supplemented with benzylaminopurine (BAP), 1.0 mg l?1, and indol-3-yl butyric acid (IBA), 0.1 mg l?1, was optimal for shoot proliferation. The presence of phloroglucinol (PG) at a concentration of 162 mg l?1 significantly increased shoot number at all auxin: cytokinin concentrations. Removal of the cytokinin and increasing the concentration of IBA to 1.0 mg l?1 resulted in adventitious root formation. PG synergistically promoted the number of roots per rooted culture but did not significantly increase the percentage rooting. Viable plants were produced from all genotypes when transplanted to soil.  相似文献   

19.
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   

20.
 以长豇豆高抗锈病品种‘ZN016’和感病品种‘之豇282’为材料，采用基质栽培，研究了外源硅(Si)处理对锈病菌胁迫下幼苗活性氧代谢的影响。结果表明，与不加Si处理植株相比，外源Si能提高锈病菌胁迫下两品种幼苗叶片POD、CAT和SOD活性，降低O2-· 产生速率和H2O2、MDA含量，提高感病品种叶片中酚类物质、GSH及AsA含量。在无病原菌侵入时,Si对上述参数影响不一。Si可显著降低感病品种的锈病病情指数，相对防效达31.7%，表明外源Si可通过提高锈菌胁迫下植株体内抗氧化酶活性，降低ROS水平，提高幼苗对锈病的抗性。  相似文献   

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