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本工作发现山地红壤地区柑桔因患缺硼症使幼果发生“内坏”而大量脱落,喷施硼肥极大地提高着果率和果实产量,并显著地改善了果实品质。土壤施用硼渣或肿柄菊(Tithonia diversifolia A.Grag)绿肥有益于改善柑桔的硼素营养。硼肥可提高柑桔叶片的光合强度,降底叶的含糖量和含水量,提高叶片的蒸腾强度,加速糖在体内的运转。尤其重要的是硼肥降低了柑桔幼果及未成熟果实的果柄离层区纤维素酶活性,抑制了离层的形成,从而降低了不正常的生理落果。本文讨论了硼肥对提高柑桔产量的重要意义,增产的生理机制以及合理施用硼肥等问题。 相似文献
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目前,氧氯化铜作为防治柑桔溃疡病的新药,在各柑桔产区陆续大量使用。据我地部分果农反映,施药后数天大面积叶片发生药害,引起严重落叶。为此,我们调查了部分药害区,了解施药时天气及 相似文献
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ABA/GAs调控特异蛋白质与柑桔的抗寒性 总被引：9，自引：1，他引：8
选用较抗寒柑桔品种兴津温州蜜柑(Citrus unshiu Marc.)枳砧盆栽苗为材料,研究了人工低温锻炼和外源 ABA喷布处理下其内源 ABA/GAs对抗寒特异蛋白质的调控作用及与抗寒性的关系。两种处理均诱导兴津柑桔苗抗寒力的发育。在抗寒力发育过程中,叶片内源ABA、ABA/GAs在第7天呈一峰状剧增趋势。同时,其基因表达发生改变,第7到21天,新产生了32、25KD两种可溶性特异蛋白质及104、37、30KD3种膜特异蛋白,第14和21天产生17和82、27KD3种膜特异蛋白,它们在17～28℃脱锻炼3天后均消失。作者提出低温、ABA首先诱导ABA/GAs的积累,由ABA/GAs启动特异性板机,最终合成抗寒特异蛋白质,进而提高柑桔之抗寒力;膜特异蛋白质贡献可能更大。 相似文献
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柑桔冻害的发生及减灾防治措施 总被引：4，自引：0，他引：4
<正>2008年的初春,一场特大的暴风雪袭卷了全国大地,出现了罕见的长期低温雪凝天气,使得柑桔冻害大面积发生。为此,笔者就柑桔冻害发生及减灾防治技术提出以下措施,仅供果农参考。1柑桔冻害症状柑桔冻害症状主要表现在叶片和枝干上,叶片受冻开始呈水浸状,叶缘向上向里卷曲,卷成圆筒状,最后干枯变黄死亡;枝干受冻使表皮与木质部开裂脱离,木质部逐渐干枯死亡。 相似文献
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一、引言 柑桔黄斑病为黄岩桔区的主要斑点落叶性病害。广泛分布于澄江两岸及其上下游桔区,一般发病率为71.8％,感病严重时导致桔树大量早期落叶、树势衰弱和翌年结果量锐减。 二、症状 柑桔黄斑病主要发生在叶片上,也可以发生在果实上。 叶片症状 在感染初期,于春梢新叶背面出现颗粒状单生或聚生的黄色突起,对阳光观察,呈半透明油渍状,以后随叶片的成长,突起部逐渐变为黄褐色,并微有裂隙, 相似文献
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以枳壳、宜昌橙、龟井、本地早、柠檬、酸橙为试材,对其离体枝叶进行湿热空气和温浴处理.测定叶片在热处理过程中游离脯氨酸含量、过氧化物酶活性、细胞膜透性的变化.结果表明:叶片游离脯氨酸含量和由叶片细胞膜透性(电导值)变化计算出的半致死温度两项指标可用于柑桔叶片耐热力的测定;本试验所测定的6种柑桔中,以酸橙较为耐热,柠檬次之,枳壳、宜昌橙较不耐热. 相似文献
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高温处理对温州蜜柑幼果膜脂过氧化作用和乙烯生成的影响 总被引：2，自引：0，他引：2
以3年生枳砧兴津温州蜜柑盆栽苗为试材,研究高温处理对柑桔幼果细胞膜脂过氧化作用和内原乙烯水平的影响,及其与幼果脱落的关系,以探讨柑桔高温热害的生理机制.结果表明:高温处理使SOD活性下降,MDA含量增加;膜脂脂肪酸组分中亚麻酸比例减少,硬脂城比例上升;致使股脂不饱和脂肪酸指数下降;加速了内原乙烯合成;加剧了幼果脱落.细胞膜脂脂质过氧化产物MDA含量与不饱和脂肪酸指数呈极显著负相关(r=-0.8407),而与幼果累积落果率呈极显著正相关(r=0.8707).细胞膜脂过氧化作用加剧可能是高温热害加速幼果脱落的初始反应. 相似文献
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B. Aloni Leah Karni Z. Zaidman Y. Riov M. Huberman R. Goren 《The Journal of Horticultural Science and Biotechnology》2013,88(5):923-928
SUMMARYHeat stress causes abscission of flowers in pepper plants and thus reduces yield. In the present study, we investigated the involvement of ethylene in heat-stress related flower abscission, by comparing the response of flowers of bell pepper, cv. Maor, known to be sensitive to flower abscission, and flowers of paprika, cv. Lehava, a resistant cultivar of Capsicum annuum. Their differing susceptibilities to high temperatures depend on light. Under high-temperature, high-light conditions, bell pepper was less susceptible than paprika, but, under high-temperature low-light, bell pepper was more susceptible. At high temperatures, flower explant abscission was much higher with bell pepper than paprika. Ethylene production (EP) by bell pepper explants reached a maximum at 34°C and decreased at higher temperatures (42 and 48 C), while in paprika EP rates were lower and reached the maximum at 42°C. Explants of bell pepper flowers were more susceptible to exogenous ethephon than paprika flowers. The sensitivity of a collection of pepper cul-tivars to heat induced flower abscission was more closely correlated with their flower sensitivity to ethephon than with the flower EP rate. We suggest that the differential susceptibility of bell pepper and paprika to heat stress is a result of both different ethylene production by their flowers and their differing sensitivities to ethylene produced under high-temperature stress. However, the sensitivity of the flower to ethylene may be more important in inducing their abscission. 相似文献
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A. J. Macnish D. E. Irving D. C. Joyce A. H. Wearing V Vithanage 《The Journal of Horticultural Science and Biotechnology》2013,88(2):293-297
SummaryExposure to ethylene gas elicits flower abscission from cut stems of Geraldton waxflower (Chamelaucium uncinatum Schauer). Ethylene response rates in plants are mediated by temperature. At 20°C, flower abscission from waxflower ‘Purple Pride’ occurred upon 12 h exposure to 1 µ11–1 ethylene. This ethylene treatment did not cause flower abscission at either 10 or 2°C. Moreover, flowers held at 2°C were insensitive to 48 h exposure to 1, 10 and 100 µ11–1 ethylene. However, increasing the duration of treatment with 1 µ11–1 ethylene at 10 and 2°C to 48 and 144 h, respectively, induced flower abscission. When flowers were held at 20°C in air without exogenous ethylene following continuous exposure to 1 µ11–1 ethylene at 2°C, the duration required to elicit flower abscission was reduced from 144 to 72 h. Collectively, these responses show that maintaining harvested waxflower at low temperature (e.g. 2°C) is an effective means to minimise ethylene-mediated flower abscission. 相似文献
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采用扫描电镜和焦锑酸钙沉淀的电镜细胞化学法,研究了番茄花柄脱落过程中离区细胞以及钙分布的变化。结果表明：离区的分离开始于皮层与维管束周围小细胞,先在这两个区域出现少量不连续的胞间空隙,并逐渐在维管组织区形成连续的断裂面,此后断裂面向中央的髓部组织延伸,先是维管组织的分离,然后是最中间的髓部以及最外侧表皮组织。钙分布研究发现脱落发生之前钙主要分布在细胞壁、质膜及液泡中。脱落发生后,钙颗粒主要分布在退化细胞壁和细胞间隙中,少量分布在细胞质中。皮层,维管束以及髓部细胞在整个脱落过程中钙分布以及钙形态明显不同,这可能是造成离区各组织在脱落中有不同分离程度的主要原因． 相似文献
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苹果采前落果与内源激素的关系 总被引：1，自引：0，他引：1
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。 相似文献
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H. Okuda 《The Journal of Horticultural Science and Biotechnology》2013,88(4):422-425
SummaryChange 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. 相似文献
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S. Mcartney M. White I. Latter J. Campbell 《The Journal of Horticultural Science and Biotechnology》2013,88(3):441-448
SummaryShade and chemical thinning treatments were applied to mature ‘Royal Gala’/M.26 apple trees either alone or in combination to study their effects on the pattern of abscission and growth of spur fruit. Natural fruit drop occurred in two distinct waves in both years; the first wave peaked 20 d after bloom (DAB) at a weekly abscission rate of c 15% in both years. The second wave of fruit drop in 2001 occurred earlier and was more intense than in the previous season. Application of NAA as a bloom thinner increased the maximum weekly abscission rate during the first wave of fruit drop in both years. Chemical fruit thinning treatments (Carbaryl in 2000, BA or delayed lime sulphur in 2001) had no effect on abscission or growth of spur fruit. Covering trees with 80% shade cloth for 3 d (2000) or 5 d (2001) stimulated a wave of fruit abscission that peaked c 10–15 d after removal of the cloth. Shade during the period from 20–25 DAB stimulated more fruit drop than earlier shade treatments, resulting in weekly abscission rates as high as 70%.There were no additive effects of combining thinning chemicals and shade treatments on abscission of fruit from spurs. However, additive effects of shade and thinning treatments were observed when measured as whole-tree crop density values, indicating that abscission of fruit from one-year wood was stimulated when low light conditions preceded application of (fruit) thinning chemicals. Shading trees from 34–39 DAB in 2000 resulted in a transient reduction and subsequent increase in the rate of dry-matter accumulation in fruit that were retained. Considerable challenges lie ahead in developing models of fruit growth that can account for the inter-dependent effects of light and crop load on fruit abscission and development that exist within an orchard environment. 相似文献
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SummaryChanges in indole acetic acid (IAA) concentrations of the peduncle, branch and abscission zone were examined during the physiological fruit-drop period, to investigate the role of endogenous auxin in the peduncle and branch on the physiological drop of the fruit. The effects of 2,3,5-triiodebenzoic-acid (TIBA), applied to the peduncle or branch, on the IAA concentration in each organ and the drop ratio were also investigated. The fruit-drop ratio increased when TIBA was applied to the peduncle (TIBA-P application), whereas it decreased when the application was to the branch (TIBA-B application). Prior to fruit drop, marked IAA accumulation occurred in the abscission zone in the control and after TIBA-P application. An IAA gradient from the branch to the peduncle was found for TIBA-P applications, but a reverse gradient for TIBA-B applications. These results suggest that the reduction of IAA polar transport above the abscission zone is necessary to promote abscission and that both IAA accumulation in the abscission zone and the IAA gradient between the peduncle and branch are involved in abscission. 相似文献
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S. Sharma M. Ritenour R. C. Ebel 《The Journal of Horticultural Science and Biotechnology》2017,92(2):120-129
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. 相似文献