1-甲基环丙烯对高温下香蕉果实后熟的影响

以香蕉果实为试材,研究了1-甲基环丙烯(1-MCP)对高温逆境下香蕉果实后熟生理的影响。结果表明:35℃高温下贮藏的香蕉果实出现了明显的青皮熟现象,而0.5μL/L的1-MCP处理24h后可显著抑制高温下贮藏果实硬度的降低,延缓果皮细胞膜透性的升高,同时有效地延迟了果肉中淀粉酶活性升高、淀粉含量下降及可溶性糖含量上升。1-MCP处理果实于35℃下贮藏9d后移入20℃环境,进一步延缓了这些后熟生理变化。1-MCP和高温均抑制了果皮叶绿素含量下降,因此1-MCP处理减轻了香蕉热害的程度,延长了果实在高温下的贮藏寿命。     

Responses of banana fruit to pro-long coating at different times relative to the initiation of ripening

Coating banana fruit with Pro-long 24 h after initiation of ripening decreased their skin permeability to gases and depressed their O₂ content. Coating the fruit immediately before ripening initiation delayed the onset of rapid ethylene production, which normally begins as the fruit start to ripen. Coating slightly suppressed rapid C₂H₄ production when applied immediately after ripening initiation, and exerted a strong, temporary inhibition of C₂H₄ production when applied 24 h later. A climacteric rise in respiration was absent from fruit coated with Pro-long immediately before or after ripening initiation; delaying coating by a further 24 h arrested development of the climacteric in mid-rise. In mid-climacteric fruit, inhibition of C₂H₄ production by coating occurred more rapidly than inhibition of respiration. Coating the fruit delayed the chlorophyll loss which normally accompanies ripening, but the magnitude of this effect declined as the coating treatment was delayed relative to ripening initiation. The effects of coating on skin colour change and on respiration appeared to be largely independent of its effect on the fruit's C₂H₄ content.     

青香蕉和黄熟香蕉果皮感病过程中5种酶活性的变化

以同一品种的未后熟的青香蕉和已黄熟的香蕉为材料,测定了接种炭疽病菌5d内果皮PPO、POD、SOD、PAL和LOX活性的变化,探讨与香蕉抗病性相关的酶类。结果表明,不论接种与否,青香蕉果皮中的PPO、POD和SOD的活性明显低于黄熟香蕉,而PAL和LOX活性高于黄熟香蕉;接种对PPO、POD和LOX活性影响不大,但引起SOD和PAL活性下降。青香蕉果皮中较低的PPO、POD和SOD的活性有利于活性氧和酚类物质的积累而产生过敏性反应,较高的PAL和LOX活性则利于苯丙烷类代谢和脂质过氧化,有利于抗病物质的形成。PAL和LOX是香蕉抗病性形成的关键酶。     

Effects of growth retarding treatments on apple tree growth,fruit maturation and fruit abscission

SUMMARY

Eight days after petal fall in 1991, mature 'Delicious'/MM. 106 apple trees and four days after petal fall in 1992, mature 'McintoshVMM. 106 were ringed, scored, root pruned (1 m from the trunk, two sides, 30 cm deep), or treated with ethephon (500 mg 1¹). Only ringing and scoring reduced vegetative growth. Ethephon advanced fruit maturation and fruit abscission, but root pruning did not affect the trees or fruit significantly. Mature 'Cort-land'/M.7a apple trees were root pruned 8 d after petal fall in 1991 and/or at full bloom in 1992. Root pruning reduced shoot growth, even in the year after treatment. Fruit abscission was reduced in 1991 and 1992 by root pruning in 1991, but root pruning in 1992 had no impact on abscission, in 1992. In an additional experiment, mature 'Mcintosh'/ MM.106 were root pruned 4 d after petal fall in 1991 or root pruned both in 1991 and at full bloom in 1992. Growth and preharvest fruit abscission were reduced in both the year of root pruning and the year after.     

The post-harvest ripening of water stressed banana fruits

SUMMARY

Maintaining banana fruit in a low humidity environment accelerated fruit ripening. This was reflected in an earlier increase in respiration and ethylene production and more advanced peel colour and pulp sugars. At the end of the trial the fruit kept in low humidity were yellow with green tips (stage 5) whereas those kept at high humidity were still green (stage 1-2). Fruit kept at low humidity did not show a large increase in pulp ethylene production compared with the fruits stored at high humidity. This difference occurred despite a large increase in the 1-aminocyclopropane-l-carboxylic acid (ACC) content of both samples, with the low humidity fruit preceding the high by two days. The peel ethylene production of the low humidity stored fruit increased dramatically as the fruit ripened, coinciding with an increase in ACC. The ACC oxidase activity of the peel reflected the ethylene production with a large increase in the low humidity stored fruit and a later, smaller increase in the high humidity stored fruit. The ACC oxidase activity of the pulp of both low and high humidity stored fruit increased gradually during storage. The changes in ethylene production are discussed with reference to banana ripening being regarded as co-ordinated by pulp ethylene production while the peel is passive, depending on pulp ethylene production for degreening.     

果树EST在果实发育和成熟研究中的应用

表达序列标签(EST)已成为植物功能基因组学研究的重要手段,在揭示植物生长发育机制方面起着重要作用。近年来果树EST研究与应用也得到快速发展,dbEST数据库中EST信息量超过5 000条的果树已达37种。着重介绍柑橘、葡萄、苹果、猕猴桃、桃、草莓和杨梅等果树EST在果实发育和成熟研究中的应用进展,并展望今后研究的热点和趋势。     

缺氮和恢复供氮对香蕉苗生长和根系形态参数的影响

【目的】探讨缺氮及恢复供氮对香蕉苗生长及其根系形态参数的影响,为香蕉苗期形态诊断和氮肥管理提供依据。【方法】通过石英砂培养试验,对比研究了缺氮程度和恢复供氮后香蕉苗表型性状、地上部和根系的干物质质量、根系形态参数等的变化。【结果】缺氮后香蕉苗呈现明显的缺氮症状;恢复供氮32 d后,香蕉苗缺氮症状消失,表型恢复正常性状。但是,缺氮程度、缺后恢复供氮对香蕉生长的影响不同,轻度缺氮不会抑制地上部生长,反而刺激根系生长,显著增加了根系干物质质量;中度缺氮时,明显抑制了香蕉苗生长,地上部干物质质量降低了19.25%,而根系干物质质量无明显变化,缺氮对根系的促生作用减弱。缺氮后,香蕉苗的总根长和直径2 mm细根的根长明显减小,轻度、中度缺氮时,香蕉苗的总根长分别为正常处理的58.3%和49.7%。但是,缺氮明显增加了香蕉苗平均根直径、总体积和直径2 mm的根系体积,轻度、中度缺氮期,香蕉苗的平均直径和总体积分别为正常处理的1.85倍和2.01倍、1.62倍和1.31倍。缺氮香蕉苗恢复供氮32 d后,缺氮表型性状完全消失,地上部和整株干物质质量分别增加了6.08%和5.24%;根系趋向正常生长,总根长特别是细根长度显著增加,平均根直径和总体积显著降低,但是,复氮处理的香蕉苗的干物质质量、根系长度、平均根直径和总体积仍达不到正常处理香蕉苗的水平。【结论】香蕉缺氮的表型性状能及时反映香蕉的氮素营养状况,缺氮对香蕉表型性状的影响通过及时补充氮肥可在短期恢复,但干物质质量、根系生长的恢复期滞后于表型性状恢复期。在香蕉栽培过程,香蕉苗期要综合考虑土壤肥力和营养特性合理施肥,避免先缺再补的施肥措施。     

诱抗剂处理对甜瓜叶部病害和果实品质的影响

以抗病品种银帝和感病品种卡拉克赛为材料,在露地条件下研究了几种植物提取液和苯并噻二唑(BTH)处理对甜瓜主要叶部病害及果实大小和品质的影响。结果表明,BTH、中草药提取液和侧柏提取液对甜瓜叶部各种主要病害的发生都有明显的抑制效果,尤其对白粉病的抑制效果最好,平均防效达75%。4种诱导剂中,BTH对各种病害的防效都较稳定,平均达51.44%,且在幼果期和伸蔓期+幼果期的预防效果均较植物提取液好。采前诱抗处理能明显提高两品种甜瓜果实品质及抗病品种(银帝)的产量,但对感病品种卡拉克赛产量影响不显著;初花期BTH处理可增加果肉厚度、提高可溶性固形物含量,并能改善果实经济性状。     

S-诱抗素处理对'巨峰'葡萄果实花青素含量及品质的影响

为研究S-诱抗素对'巨峰'葡萄果实生长、果实着色效果、果实品质、花青素含量及相关酶活性变化的影响,指导S-诱抗素在'巨峰'葡萄生产上合理使用,采用不同质量浓度(0、100、200、300、400 mg/L)的S-诱抗素在葡萄果实转色初期进行茎叶喷雾处理。结果表明:S-诱抗素处理后外观色泽得到有效改善,葡萄果皮着色指数(CIRG)、花青素、叶绿素含量显著提高;随着时间推移,果实可溶性固形物、维生素C含量有不同程度的提高,可滴定酸含量明显下降;花青素合成相关酶PAL、CHI活性提高。葡萄果实转色初期(第2次膨大期,转色面积为50%～10%)不同浓度S-诱抗素处理对葡萄着色存在低促高抑的影响,其中用300mg/LS-诱抗素茎叶喷雾处理1次作用效果最好。     

MaCDPK7, a calcium-dependent protein kinase gene from banana is involved in fruit ripening and temperature stress responses

Calcium-dependent protein kinase (CDPK) is an important Ca²⁺ sensor in plant development and responses to stress stimuli. Banana fruit is a typical climacteric- and chilling-sensitive fruit. The roles of CDPK genes in the ripening and chilling response of banana fruit are unclear. We isolated a cDNA fragment with full-length coding MaCDPK7 (HM061075) from fruit peel tissue. Induction of MaCDPK7 expression in fruit peel was observed 0.5 h after phytohormone ethylene treatment, earlier than the up-regulation of MaACO1 and MaACS1, coding a 1-aminocyclopropane-1-carboxylate oxidase and 1-aminocyclopropane-1-carboxylate synthase, respectively. Penetration of calcium signaling blockers, EGTA, or LaCl₃ inhibited the ripening and gene expression of MaCDPK7, MaACO1, and MaACS1 in the in vitro cultured peel pieces, but Ca²⁺ application removed the inhibitory effect of EGTA and LaCl₃. This suggested that MaCDPK7 might be a positive regulator involved in the calcium signaling in banana fruit ripening. Under temperature stresses, we found that MaCDPK7 gene expression increased 3 h after hot water dipping (HWD). The HWD-treated fruits exhibited markedly less chilling injury (CI) than control fruits in cold storage. Stored at 7°C (CI temperature) dramatically increased MaCDPK7 gene expression, while pre-treatment of HWD repressed the induction in cold storage. These results show that the MaCDPK7 gene is involved in regulating banana fruit ripening and chilling resistance induced by heat treatment.     

猕猴桃果实成熟前补钙对果实含钙量的影响

猕猴桃果实成熟前用喷叶法和喷果法补钙，可显著提高果实中的钙含量。喷叶较喷果效果好。用Ca(NO3)2喷叶，比用CaCl2处理效果好，差异显著。而果实对CaCl2和Ca(NO3)2的吸收选择性差异不显著。经补钙处理的果实采后进行贮藏效果观察发现：用Ca(NO3)2喷叶处理的果实贮藏性较好，用其喷果处理次之；用CaCl2喷果和喷叶处理的果实贮至28天软果率均达到90％。     

脆肉梨果实成熟过程中质地性状的变化

【目的】探讨脆肉梨成熟过程中不同时期、果实不同部位质地性状的差异和变化规律。【方法】以脆肉梨品种‘华酥’和‘圆黄’为试材,采用食品物性分析仪质地多面分析法(TPA)和穿刺试验,测定果肉脆度、硬度、黏着性、弹性、胶黏性、咀嚼性和果皮硬度等7个质地性状。【结果】各质地性状在梨果实成熟过程中均发生显著变化,而且果实萼部、中部和梗部3个部位的质地性状均存在差异;除黏着性与其他参数间的相关性较差之外,果肉脆度、果肉硬度、弹性、胶黏性、咀嚼性和果皮硬度之间均呈极显著正相关。【结论】首次明确了在梨果实成熟过程中各部位质地性状的变化规律,可以为梨适宜采收成熟度的确定提供理论依据。     

Effects of multiple applications of methyl jasmonate on fruit ripening,leaf gas exchange and vegetative growth in fruit trees

Summary

Multiple applications of methyl jasmonate (Me-J), at 10.mM, enhanced the rate of fruit ripening in peach ‘Redhaven’. The effect of Me-J on red colour development and fruit firmness was most pronounced in fruit treated six times with Me-J. Lower concentrations of Me-J had no effect of fruit colour. Me-J, at 10.mM, significantly reduced stomatal conductance, photosynthetic rate and transpiration rate of crabapple leaves, but had no effect on these parameters in peach leaves. The short-term inhibitory effects of Me-J on leaf gas exchange in crabapple persisted for up to 24 h. Fourteen applications of Me-J over a period of 28 days resulted in a 60% decrease in the concentration of chlorophyll in leaves. These Me-J applications also reduced the length of new branches, leaf number and leaf fresh weight by 65%, 31% and 47%, respectively. In peach, Me-J induced some leaf chlorosis and early leaf senescence within two weeks of the treatments which resulted in significant reductions in shoot length.     

不同施肥措施对蓝莓植株生长及果实品质的影响

对伯克利蓝莓生长的3个关键期即发芽前、初夏、秋季时,施用3种肥料即硫酸铵、磷酸二铵、氮磷钾复合肥,每株按3个不同的施肥总量即25g、50g、100g进行搭配施肥试验,研究对蓝莓植株生长与果实品质的影响。结果表明,以施用NPK复合肥每株50g,分春夏秋3次分施时,蓝莓的株高、冠幅、新梢长度等生长状况,单果重、单株产量,果实的可溶性固形物含量、有机酸含量、Vc含量等品质指标均最佳。     

Gibberellin-like substances during ripening of olive fruit

The activity of gibberellin-like substances in olive fruits, Olea europea L. cultivar ‘Manzanillo’, was investigated. A decrease in gibberellin activity was found with the transition from green ripe to black ripe; simultaneously, the activity of inhibiting substances was demonstrated. The general aspects of ripening and their reference to the specific processes taking place in the olive fruit are discussed.     

Effects of 1-methylcyclopropene (1-MCP) on ripening of apple fruit without cold storage

Summary

The objectives of this study were to determine the efficacy of 1-methylcyclopropene (1-MCP) treatment on ripening of ‘Tsugaru’ fruit at different stages of maturity (early, mid-, and late harvest) and the responses of the early- to late-maturing apple cultivars,‘Tsugaru’,‘Hongro’ and ‘Fuji’, respectively, during storage at ambient temperature (20º ± 2ºC). Fruit at different stages of ripening were treated with 0.5, 1.0, or 2.0 µl l^–1 1-MCP for different durations (e.g., 1.0 µl l^–1 1-MCP for 8 h, 16 h, or 24 h) or with various delays before treatment (e.g., 1.0 µl l^–1 1-MCP on the day of harvest, or 1 d, or 2 d later). Application of 1-MCP to unripe fruit inhibited ethylene production, lowered the rate of respiration and maintained titratable acidity (TA) more effectively than when more mature fruit was treated. However, the effects of 1-MCP on flesh firmness were similar for apples at mid- or late harvests. 1-MCP treatment of early-harvested fruit of the early-maturing ‘Tsugaru’, which had the highest level of ethylene production and respiration rate, inhibited softening and loss of TA to a greater extent than for late harvested fruit. The same pattern of softening was found for ‘Hongro’ and ‘Fuji’. Firmness of ‘Tsugaru’ and ‘Fuji’ apples was maintained after 8 h treatment with 1.0 µl l^–1 1-MCP, while a 16 h treatment was required for ‘Hongro’. Treatment delays of ≤ 2 d before the application of 1-MCP had no negative impact on fruit firmness. Overall, these results indicate that 1-MCP can be used to maintain the quality of non-refrigerated apples.     

采后褪黑素处理对杏果实成熟的影响

为研究采后外源褪黑素处理对杏果实低温贮藏期间品质及生理的影响,以确定最佳的褪黑素处理浓度,并明确其对杏果实成熟的调控机理,试验以‘兰州大接杏’为材料,采用50～1 000μmol/L褪黑素溶液浸泡杏果实15 min,分析低温[(2±2)℃,相对湿度73%±2%]贮藏期间杏果实乙烯释放量、呼吸强度、硬度、色泽等品质及生理指标的变化。结果表明:不同浓度的外源褪黑素溶液处理均显著提高了杏果实的呼吸强度以及乙烯释放量,贮藏第12 d时,50μmol/L外源褪黑素处理杏果的呼吸强度较对照提高32.8%,同时,贮藏第8 d时,该处理的乙烯释放量为对照的2.2倍;其次,50μmol/L褪黑素溶液处理有效促进了杏果实的软化。此外,褪黑素处理杏果实后有利于提高果实可溶性固形物、可滴定酸含量,有效保持果实抗坏血酸含量。综合来看,50μmol/L外源褪黑素处理可通过提高采后杏果实乙烯释放量和呼吸强度,促进果实成熟,进而加速杏果实最佳食用品质的形成。     

Effects of salinity at two ripening stages on the fruit quality of single-truss tomato grown in hydroponics

Summary

Single-truss tomato plants grown hydroponically (wet-sheet culture) were exposed to a salinity (EC) of 5.0 dS m²¹ or 8.0 dS m²¹ at two fruit ripening stages, the immature green stage and the decolouring stage. These salinities were achieved by adding NaCl to the standard solution, which had an EC of 2.4 dS m²¹. Increased salinity at the immature green stage improved fruit quality more than increased salinity at the decolouring stage but decreased fruit yield more. The reduction in fruit yield was due to a decrease in fruit weight but not in fruit number. Salinity increased the concentration of soluble solids, citrate, ascorbic acid, K, chlorophyll a, chlorophyll b, lycopene, and carotene in the fruit, but the absolute amount of these constituents per fruit was decreased or not affected. These results suggest that the improvement in fruit quality induced by the salinity is caused by the reduction of water import into the fruit. The effectiveness of both salinities was significantly bigger when it was applied at the earlier development stage, suggesting that mature fruit would be less sensitive to strength of the EC.     

The acid metabolism of Annona fruit during ripening

Summary

Annona fruit ripening is associated with a high rate of reassimilation of respired CO₂, and a large increase in titrable acidity mainly due to malic acid accumulation. However, little is known about the mechanisms involved in acidity changes. In this work, the kinetic properties and activities of phosphoenolpyruvate carboxylase, malate dehydrogenase and malic enzyme, implicated in the regulation of malate metabolism and by extension in cytoplasmic pH, have been analysed. Kinetic studies revealed that the Km values of NADP-malic enzyme for malate were higher than those of malate dehydrogenase for oxaloacetate (1.44 ± 0.03 mM v 0.78 ± 0.02 mM). These results together with the higher V_max value of malate dehydrogenase (more than 26-fold) indicated more efficiency in the reaction of malate synthesis v decarboxylation. The in vitro properties of the enzymes and the fact that the activity of malate dehydrogenase is much higher than the activity of NADP-malic enzyme account for the particular high titratable acidity in cherimoyas during ripening. Our results further indicate that the balance between malic acid synthesis and consumption seems to be effectively regulated and consistent with a controlled cytoplasmic pH value, measured by ³¹Phosphorus nuclear magnetic resonance spectroscopy.     

Effect of ethephon (2-chloroethylphosphonic acid) on the fruit ripening characters of rabbiteye blueberry

Effect of ethephon (2-chloroethylphosphonic acid) application on rabbiteye blueberry fruit quality during the growth period was investigated. Ethephon treatment stimulated the decrement of titratable acidity, anthocyanin accumulation and fruit softening 4 days after treatment and the promoting effects continued through the investigation period. The ripening promotion effect of ethephon on total soluble solids content was observed only 8 days after treatment. Ethephon treatment did not affect the fruit enlargement during the investigation period. From these results, it is concluded that ethephon application for rabbiteye blueberry promote the fruit ripening, but the stimulatory effects of ethephon on fruit ripening were different in degree on each ripening characters.