苹果采前落果与内源激素的关系

为了探讨苹果采前落果与内源激素之间的关系,在采前8周间定期测定了不同苹果品种的果柄、果台和离层形成部位组织中IAA、ABA含量;在采收前20d内定期测定了离层部位组织中细胞壁分解酶(Cellulase)的活性;在收获期测定了果实乙烯的发生量。结果表明:不同品种果柄、果台和离层部位组织中IAA和ABA含量变化有差异,但它们变化的总趋势相似,都是随着果实成熟IAA含量下降,而ABA含量上升;不同品种的成熟果实中乙烯发生量有很大差异,以落果多的品种显著大于落果少的品种;采前落果重的品种离层部位组织中细胞壁分解酶的活性在果实成熟期急剧增加。由于果实进入成熟阶段后,IAA含量下降,ABA含量升高,ABA/IAA之间的相对平衡被打破,高ABA/IAA以及高乙烯会刺激离层组织中细胞壁分解酶的活性增高,进而促进离层形成,这可能是导致落果发生的原因。     

An increase in citrus fruit (Kiyomi tangor) abscission induced by ABA is accompanied by an IAA increase in the abscission zone and ethylene production

Summary

Change in IAA concentrations in the peduncle, branch and intervening abscission zone were measured to clarify the involvement of IAA in citrus fruit drop in response to ABA application. Results indicating the importance of an IAA increase in the abscission zone were obtained. One day after application of ABA, the concentration of IAA in the abscission zone showed a temporary increase and then a decrease. The concentration of IAA in the abscission zone was dependent on the concentration of ABA applied. Changes in the production of ethylene, which is involved in the process of abscission and which is induced by IAA, in explants from treated leafy inflorescences, were examined. The fruit-abscission ratios were also investigated in relation to the time required for preparation. Explants sampled 0±1.d after application showed little abscission or ethylene production during the first 24 h incubation. During the next 24 h, almost all the ABA-applied explants abscinded, as did the control, but the former produced 3±4 times more ethylene. ABA-applied explants, sampled 2.d after application, abscinded and produced ethylene markedly during the first 24.h, whereas the control explants did not abscind. Control and ABA-applied explants, sampled 3 d after application, showed no differences in their abscission ratios and ethylene production. These findings indicate that a temporary IAA rise in the abscission zone, observed one day after application, is involved in ethylene production in ABA-induced citrus fruit drop.     

ABA和IAA对猕猴桃果实成熟进程的调控

以中华猕猴桃和美味猕猴桃果实为试材，研究果实成熟过程中内源ＡＢＡ，ＩＡＡ和乙烯的变化以及外源ＡＢＡ和ＩＡＡ处理对果实后熟软化进程的调控及其在生理基础。结果表明，果实采后初期，ＡＢＡ含量迅速升高，在２－４ｄ达到最大值，之后快速下降；在ＡＢＡ下降过程中，乙烯进入跃变期，果实后熟进程加快，外源ＡＢＡ处理增加内源ＡＢＡ含量，加快内源ＩＡＡ的降解，促使脂氧合酶活性峰值提前出现，加速果实软化，果实后熟进程中，     

ABA和乙烯与甜樱桃果实成熟的关系

以‘红灯’甜樱桃为试材,分析了果实生长发育过程中内源脱落酸(ABA)和1-氨基环丙烷-1-羧酸(ACC)含量的变化以及外源ABA和乙烯利处理对果实成熟进程的影响,探讨了ABA和乙烯与甜樱桃果实成熟的关系。结果表明:果皮和果柄中的ABA含量呈逐渐上升的趋势,在花后43d达到最大值。果肉中的ABA含量呈先下降后上升再下降的趋势,在花后14d时含量较高,之后下降,花后25d开始又迅速上升,至花后36d出现一高峰,之后下降。种子中的ABA含量和果肉表现出相似的变化趋势,但ABA峰值的出现早于果肉。ACC含量在果实的整个发育过程中变化不大,并且一直处于很低的水平,最大值不足0.02nmol·g-1FW。外源ABA能促进内源ABA的合成和乙烯的释放,但对内源ACC的变化没有显著影响。乙烯利持续处理能促进乙烯的释放,提高内源ACC的水平。外源ABA能提高甜樱桃果实的成熟度和花青苷含量,促进果实软化。乙烯利处理对果实的硬度、花青苷含量和成熟度指数均没有显著影响。     

The role of ethylene in abscission of sweet orange promoted by exogenous application of the abscission agent 5-chloro-3-methyl-4-nitro-1H-pyrazole (CMNP)

Mature ‘Valencia’ fruit were treated with 5-chloro-3-methyl-4-nitro-1H-pyrazole (CMNP), and the ethylene inhibitors aminoethoxy vinyl glycine (AVG) and silver thiosulfate (STS), to assess involvement of ethylene in abscission via CMNP. Fruit detachment force (FDF) and ethylene evolution were measured over time. Accumulation of the ethylene precursor 1-aminocyclopropane-1-carboxylate (ACC) in peel upon CMNP application was assessed and impact of application of ACC on FDF was estimated when applied 1 cm away from the abscission zone (AZ), to determine its potential as a signaling molecule in promoting fruit loosening. CMNP when applied alone reduced FDF by 50%. AVG and STS inhibited fruit loosening considerably at 500 µM and 10 mM, respectively, when applied with 2 mM CMNP. ACC accumulation in peel was highest 2 days after CMNP application, which preceded the maximum decline in FDF which occurred a day later, indicating that ACC serves as a potential signaling molecule that triggers abscission in the AZ. The results of the study support the hypothesis that abscission via CMNP application is at least partly ethylene dependent. However, the decline in FDF by ACC was less than 50% of control which suggested involvement of another pathway in abscission via CMNP in sweet orange.     

不同授粉处理对沙田柚果实发育中内源激素水平变化的影响

沙田柚自花授粉果实的重量和体积均低于异花授粉处理。与未授粉子房相比,授粉子房迅速膨大。授粉处理可使子房内源激素(ＩＡＡ)、赤霉素(ＧＡ１＋３)、细胞分裂素(ＣＴＫｓ)和脱落酸(ＡＢＡ)水平急剧上升,异花授粉处理更明显。未授粉的子房内源生长促进类激素含量保持低水平,生长抑制类激素(ＡＢＡ)水平上升,这种激素水平的失衡最终造成未授粉子房的迅速凋落。果实生长发育初期,自花授粉幼果内源激素促进类激素含量低于异花授粉处理,ＡＢＡ水平明显高出后者,果实迅速增长期间,内源ＩＡＡ和ＧＡ１＋３有两个明显的高峰期,显示ＩＡＡ和ＧＡ１＋３含量与果实迅速膨大有密切关系。果实发育后期直至成熟,内源ＡＢＡ水平逐渐升高。测定果实发育整个过程的ＡＢＡ/(ＩＡＡ＋ＧＡ１＋３＋ＣＴＫｓ),未发现规律性的变化。     

Hormonal regulation of physiological leaf spot and premature leaf abscission in ‘Golden Delicious’ apple trees

Exogenous growth substances (GA₄₊₇, IAA, PBA, and ABA) alone and in combination were applied as leaf dips to young ‘Golden Delicious’ apple trees in a growth room at 21 °C. All treatments containing GA₄₊₇ accelerated the incidence of physiological leaf spot over treatments without GA₄₊₇, ABA alone delayed the appearance of leaf spot. PBA, PBA + GA₄₊₇, and PBA + GA₄₊₇ + IAA retarded the abscission of spotted leaves.GA₄₊₇ and GA₄₊₇ + PBA also accelerated leaf spot development in bearing ‘Golden Delicious’ trees in the orchard.Fumigation of apple trees with ethylene at 2, 10, and 20 ppm had no influence on the occurrence of leaf spot or premature abscission.     

Effects of 1-aminocyclopropane carboxylic acid on the rate of ethylene release from detached fruiting spurs and on fruit abscission in apple

Summary

1-Aminocyclopropane carboxylic acid (ACC) was applied to apple (Malus × domestica Borkh.) trees or to individual fruiting spurs between full bloom (FB) and 31 d after full bloom (DAFB; mean fruit diameter of 20 mm) to determine the effects of ACC on the ethylene released from detached spurs and on fruit abscission. The rate of ethylene release from detached fruiting spurs increased 1 d after applying 50 mg l^–1 ACC at full bloom or 16 DAFB (mean fruit diameter of 10 mm), but ACC had a reduced effect on the rate of ethylene release when it was applied 31 DAFB (mean fruit diameter of 20 mm). ACC reduced fruit set in ‘GoldRush’ apple in a concentration-dependent manner in 2009 and in 2010, but had no thinning activity on ‘Pink Lady’ in 2010. ACC at 200 mg l^–1 resulted in the yellowing and abscission of ‘GoldRush’ spur leaves in 2009, but not in 2010. The effects of combining ACC and 5 mg l^–1 naphthaleneacetic acid on fruit set in ‘GoldRush’ apple were additive. The application of 200 mg l^–1 ACC when fruit are ca. 10 mm in diameter may therefore be a useful chemical thinning treatment for apple fruit.     

ABA 和乙烯对荔枝果实成熟和着色的调控

 荔枝果实幼果期ABA 含量很高, 之后下降, 在转红前1 周急剧上升, 形成一个峰值。果皮、果肉乙烯释放量的变化与ABA 相似, 但其跃变发生在ABA 之后, 且跃变较小。伴随着乙烯的跃变, 有一个糖代谢和转化酶活性的跃变。于转熟前用STS 处理荔枝果实, 导致果实转色和成熟延迟。果实发育后期, ABA 急剧增加可能诱导了乙烯的合成, 乙烯启动果实成熟, 果皮转红着色。     

Effects of temperature on fruit thinning with ethephon in ‘Golden Delicious’ apples

The effect of temperature on the ability of 2-chloroethylphosphonic acid (ethephon), when applied at 20 mm stage of fruit development, to induce ethylene evolution of fruit and leaves and abscission of fruit and leaves was determined using 9-year-old root-bagged ‘Golden Delicious’/M.27 apple (Malus domestica Borkh.) trees in environment-controlled growth rooms. Ethephon at 400 μL L⁻¹ effectively thinned apples, and its thinning effect was not affected by increasing day/night temperature from 21.1/10 to 32.2/21.1 °C. Fruit ethylene evolution was enhanced by application of ethephon. Peak fruit ethylene evolution occurred 1 day after application of ethephon when day/night temperature was 32.2/21.1 °C whereas it occurred 2 days after application of ethephon at a day/night temperature of 21.1/10 or 26.7/15.6 °C. Ethephon increased leaf ethylene evolution drastically but it did not induce leaf abscission regardless of temperature.     

柿果实1 - 甲基环丙烯处理对成熟软化的影响

 研究了乙烯受体抑制剂1 - 甲基环丙烯(1-MCP) 处理对火柿果实成熟的影响。结果表明: 1-MCP 处理能显著抑制果实乙烯释放, 延缓其跃变出现时间, 推迟ACO (ACC 氧化酶) 活性峰及呼吸跃变,抑制采后初期ACO 的活性及呼吸速率的上升, 并能阻止硬度的下降, 推迟其成熟软化, 延长贮藏期。     

The Effects of Some Growth Regulators on Peach Flower Bud Abscission

Applications of growth regulators to detached peach laterals in winter had variable effects on flower bud abscission. GA₃ and GA₄₊₇ increased bud abscission while IAA, BA and ABA inhibited abscission. Ethephon had a variable effect. Interactions were obtained between the compounds generally with IAA or GA playing the major role. GA had a peak of activity during a critical period in late winter indicating a variation in responsiveness. Variations in sensitivity to GA were obtained for different cultivars. Field applications of GA₃, GA₄₊₇, and ethephon to Elberta peach trees in winter, alone and in various combinations, promoted bud abscission.     

‘库尔勒香梨’花萼端不同形状果实的矿质元素和内源激素含量比较

以库尔勒香梨(Pyrus sinkiangensis Yü‘Korla Xiangli’)果实为材料,研究了脱萼不突起、宿萼不突起和宿萼突起等3种形状以及同一形状的果柄端、胴部和花萼端等3个部位的矿质元素、内源激素和品质差异。结果表明,果皮的N、Ca、Mg、B含量较果肉高,而N/Ca和K/Ca则较果肉低;宿萼突起果中,N、K、P含量和N/Ca显著高于脱萼不突起果和宿萼不突起果;花萼端Ca含量显著低于果柄端和胴部,而N含量和N/Ca均显著高于果柄端和胴部。果皮的IAA、ZR和ABA含量较果肉高,并且宿萼突起果的IAA含量和(ZR+IAA+GA3)/ABA显著高于脱萼不突起果和宿萼不突起果,ABA含量则显著低于脱萼不突起果;果实不同部位的各内源激素分布未发现明显变化规律。脱萼不突起果综合品质好于宿萼果,花萼端可溶性固形物和维生素C含量显著高于果柄端和胴部。     

核桃果实成熟过程中呼吸速率与内源激素的变化

对核桃颗粒成熟过程中呼吸速率，乙烯释放量和内源激素ＩＡＡ（吲哚乙酸）、ＡＢＡ（脱落酸）、ＧＡ３（赤霉素）、ＺＲ（玉米素核苷）、Ｚ（玉米素）含量的变化进行了测定，结果表明，除种仁中Ｚ含量较上，青皮中其它激素水平均高于种仁。随着颗粒的成熟，ＩＡＡ、ＧＡ３、Ｚ、ＺＲ含量及乙烯释放量均呈下降趋势；而青皮中ＡＢＡ含量则逐渐增加。果实成熟后青皮中ＧＡ３和种仁中Ｚ含量明显增长，颗粒乙烯释放量明显增高，而采后果实     

喷施GA3和2,4-D对留树保鲜脐橙落果和内源激素含量的影响

 以纽荷尔脐橙（Newhall Navel Orange）为试材,测定喷施GA₃和2,4-D的植株留树保鲜果实的落果率和果实内源赤霉素（GA）、生长素（IAA）、玉米素核苷（ZR）、脱落酸（ABA）含量的变化,探讨内源激素与留树保鲜脐橙落果的关系。结果表明：植物生长调节剂处理能降低果实内源GA、IAA、ZR含量下降的速度,减缓内源ABA及ABA/（GA + IAA + ZR）的升高,减少留树保鲜过程中的落果,其中以20 mg · L^-1 GA₃ + 20 mg · L^-1 2,4-D混合处理的效果最好,且留树保鲜应以60 d左右为宜。初步分析认为内源GA、IAA、ZR含量的下降,内源ABA及ABA/（GA + IAA + ZR）的升高加速了果实离层的产生,共同促进了留树保鲜脐橙果实的衰老脱落。     

甜樱桃果实NCED基因的克隆及其表达

为了进一步研究ABA在甜樱桃果实成熟过程中的作用,通过RT-PCR以及RACE-PCR方法从甜樱桃果实克隆得到了ABA合成关键酶NCED基因片段PacNCED1及其3′ 末端序列,从乙烯利处理果实中克隆得到了乙烯合成关键酶ACO基因片段PacACO1。推测的PacNCED1和PacACO1氨基酸序列与其它物种的NCEDs和ACOs氨基酸序列具有很高的同源性。通过半定量RT-PCR及定量RT-PCR方法分析了PacNCED1和PacACO1的表达模式,发现PacNCED1在甜樱桃果实发育的整个过程以及不同部位都有表达,在果肉和种子中的表达不断增加,在果实成熟之前达到最高峰,而在果柄中的表达则在果实完熟时达到最大。PacNCED1在未失水的叶片和根中有微弱表达,但在失水叶片中的表达急剧上升,表现出与失水的相关性。外源ABA和乙烯利能促进PacNCED1在果实中的表达,而NDGA和IAA对PacNCED1在果实中的表达没有显著影响。在甜樱桃果实发育过程中并没有检测到PacACO1的表达信号,但是外源乙烯利和ABA处理能诱导其在果实中的表达。     

SO2对葡萄采后呼吸强度及内源激素的影响

采用气相色谱法和改进的高效液相色谱法研究发现：‘无核白’葡萄果粒为非跃变型呼吸类型，其乙烯释放量很低，但释放潜力很高，切伤后乙烯释放速率迅速增高；果梗和穗梗为跃变型呼吸类型，有很高的呼吸高峰和乙烯释放高峰。适量的ＳＯ２保鲜处理对葡萄的呼吸强度、脱落酸（ＡＢＡ）含量及乙烯释放具有明显抑制作用，对生长素（ＩＡＡ）、赤霉素（ＧＡ）有促进作用，既可抑制葡萄生理衰老，又可减轻葡萄的落粒，延长葡萄采后贮藏寿命     

Reducing preharvest drop of ‘Temple’ orange fruits by 2,4-D — Role of cellulase in the calyx abscission zone

One or two treatments of 2,4-D (18 p.p.m.) applied to ‘Temple’ orange trees during the last 6 weeks before the regular picking-period in late January, successfully reduced natural preharvest fruit abscission, allowing picking to be delayed by at least one month, and thus producing better external and internal fruit quality. It has been demonstrated for the first time that the delaying effect of auxin treatment on preharvest abscission was directly related to the decrease in the activity of endo- and exo-cellular cellulase. Most of the increase in cellulase activity during the abscission process was, however, due mainly to the activity of exo-cellular cellulase. When frost occurred a few days after application of 2,4-D, the auxin treatment significantly decreased total cellulase activity, thus reducing fruit abscission.The data proved that, except for the difference in the length of time between application and the onset of the hormone effect, the control mechanism of 2,4-D on abscission and on cellulase activity in intact fruit is similar to that previously reported for fruit explants.     

基质培对草莓糖酸和某些生理特性的影响

研究了基质培对丰香和枥乙女草莓糖酸和某些生理特性的影响。结果表明基质培草莓的果实可溶性固形物和可滴定酸含量均略有下降,但不影响固酸比。果糖、葡萄糖和蔗糖三者的比例发生了变化,其中葡萄糖稍有增加,果糖和蔗糖略有减少。酸性转化酶(AI)和中性转化酶(NI)活性在果实刚着色时变化不大,糖积累也较少;进入着色期后,AI和NI活性明显升高,糖积累亦较多。ABA含量在果实着色初期几乎为0,果实2/3着色后直线上升,这时果实正处于糖迅速积累阶段,基质培的ABA含量始终略高于土培;IAA含量在果实成熟过程中一直呈下降趋势,A鄄BA含量的迅速增加发生在IAA含量快速下降之后,基质培的IAA含量始终低于土培。     

Effect of pollination on cell division,cell enlargement,and endogenous hormones in fruit development in a gynoecious cucumber

To study the effect of pollination on fruit development in gynoecious and parthenocarpic cucumbers (Cucumis sativus L. cv. NK × AN8), the number of cells, cell size, mitotic index, histone H4 gene expression, and concentrations of endogenous cytokinins and auxin were compared in fruits that had developed from pollinated and non-pollinated flowers. Fresh weight was more in the pollinated group 4–12 days after anthesis (DAA) in both winter and spring, and 2–6 DAA in the summer. In winter, mitotic index increased from anthesis to 2 DAA and then decreased gradually in the pollinated group but immediately after anthesis in the non-pollinated group. Histone H4 gene in the pericarp zone was expressed more strongly during the period from pre-anthesis to 2 DAA in the pollinated group in summer. Concentrations of zeatin, isopentenyladenine, and indole-3-acetic acid (IAA) were higher in the non-pollinated group 2 and 4 DAA and peaked 4 DAA in spring whereas isopentenyladenine and IAA showed no distinct peaks in the pollinated group. These results are incompatible with the idea that pollination activates cell division by stimulating the synthesis of cytokinins and auxin in cucumber fruits.