温州蜜柑果实品质与生态条件关系的探讨

一、品质的重要性及构成要素柑桔是热带、亚热带常绿果树,果实形色美观、营养丰富、甜酸爽口,颇受人们喜爱。但是,不同的柑桔种类、品种和不同地区生产的柑桔,其品质差异很大。目前,我国柑桔的栽培面积仅次于巴西、美国,产量却僅占世界总产量的3%,每年每人平均柑桔消费量不到2kg,与世界人均消费量15kg比较有很大差距,因此无论是柑桔数量还是质量,都不能满足人们日益增长的需要,特别是品质。在国际市场上缺乏竞争能力。柑桔果实品质由外形和内质两部分组成,外形包括果实形状(纵横径比)、大小和果皮的色泽、粗细等,内质包括果味、香气、营养成分、维生素含量、糖酸度等。在这些要素     

用于柑桔成熟度无损检测的色度频度序列法研究

农产品内部品质无损检测技术是确定水果最合适的采收期和对成熟度不一致的农产品进行准确分级的关键．为了建立利用计算机视觉技术进行柑桔成熟度的无损检测的方法,本研究建立了用于柑桔成熟度检测的计算机视觉系统,研究了柑桔图像颜色的描述方法,通过分析比较,认为在利用水果可见光彩色图像检测水果成熟度时,宜采用HSI颜色模型空间;提出了用与各个色度对应的像素在图像中出现的频度构成的频度序列描述图像的颜色信息的新方法,并利用人工神经网络方法建立了根据柑桔图像的色度频度序列判断柑桔成熟度的映射器,这一映射器检验252只成熟度不同的尾张系柑桔的结果为,对成熟果实和未熟果实的判断正确率分别为 79 1％和63．6％,总的判断正确率为77．8％,这表明尾张系柑桔果实的表皮颜色与成熟度之间具有相关性,可以通过利用计算机视觉技术测定柑桔的表皮颜色信息来判断柑桔的成熟度．     

影响柑桔树开花结果性能的生态生理因素

本文报道1988年和1989年春夏之际异常和正常的桔园小气候环境对柑桔树开花结果物候期、抽梢生长、幼果发育、生理落果、当年果实产量和品质等性能的影响。结果表明,柑桔树的座果率受许多生态生理因素制约,但第一次生理落果主要与开花期桔园的小气候环境有关,第二次生理落果则与树体营养生理代谢密切相关。据此提出了预测预报柑桔树第二次生理落果的指标及其防御措施。     

日本在柑桔保健作用研究中的新进展

在以往的研究中,已报道了柑桔类果实除了富含维生素Ｃ等成分外,尚含有类黄酮、类胡萝卜素、类柠檬素、脱氧肾上腺素等多种活性成分,具有抗癌。预防糖尿病、动脉硬化和高血压中风症等多种保健功效,但对这些物质中起作用的具体化学成份、作用机理以及不同柑桔种类品种的差异并不了解。最近日本在这方面的研究获得了新的重大进展。在预防糖尿病、动脉硬化等成人病方面早先的研究表明柑桔果实中的纤维素主要通过对糖份的吸附、加快血液中多余糖份的排泄而有预防糖尿病的效果;柑桔果实还富含橙皮耷（维生素Ｐ）和芦丁,能强化血管,可预防动…     

柑桔褐圆蚧的发生与预报

<正> 柑桔褐圆蚧Chrysomphalus aonidum L.为害柑桔枝叶及果实,常常引起树势衰弱和影响果实品质,是柑桔生产上的重要害虫。因其蚧壳有角质化程度较高的蜡质保护,故在防治上一般药剂难以奏效。但初孵幼蚧裸露或仅分泌一层较薄的蜡质,这时期则有利于药剂防治。因此,弄清发生为害规律、掌握幼蚧发生时期,对其测报和防治有着重要意义。     

根外喷硼对芒果营养生长、圆锥花序发育、花性、座果和果实性状的影响

硼对苹果、柑桔、葡萄等果实具有良好效应已见诸报道,关于硼酸对Langra芒果营养生长、果实品质的影响也有过报道。但硼酸对芒果开花、花性的影响方面资料很少。本试验旨在探讨硼酸对Dashehari芒果营养生长、花性、座果和果实理化性状的影响。     

柑桔潜叶蛾对柑桔的为害及经济阈值的研究

调查福州市郊柑桔园柑桔潜叶蛾（Ｐｈｙｌｏｃｎｉｓｔｉｓｃｉｔｒｅｌａ）在雪柑、芦柑、蕉柑、福桔４个品种上的为害情况．根据其为害特性和柑桔果实产量大小年份可能给经济阈值带来的误差,采用同一树上以秋梢为计量单位,环割被测枝条（避免枝条间养分重新分配而带来误差）的方法,研究了为害秋梢的叶片光合作用强度,当年和翌年春夏梢的生长量,翌年果实品质和重量,以及叶片被害程度与柑桔潜叶蛾幼虫密度的关系．结果表明,柑桔受潜叶蛾为害后具有一定的光合补偿及组织愈伤的补偿能力;根据福州地区１９９４年柑桔生产力,以雪柑为品种确定经济阈值为１．２１头１龄幼虫／嫩叶;缩小了经济阈值受果实产量大小年份差异而带来的误差;同时考虑品种、柑桔园水热条件、产量水平、天敌作用等多种生态因子,建立了多因子经济阈值模型     

桔园施用有机肥对主要害虫发生的影响

为了通过合理施肥控制柑桔害虫的发生、从而减少喷施防虫农药的次数,本研究在桔园比较了单施有机肥、单施化肥的柑桔树上柑桔木虱Diaphorina citri Kuwayama、柑桔全爪螨Panonychus citri McGregor、柑桔潜叶蛾Phyllocnistis citrella Stainton等主要害虫的发生数量。结果表明,单施有机肥柑桔木虱、柑桔全爪螨发生数量显著低于常规施用化肥的施肥方法,柑桔潜叶蛾的为害没有显著变化,柑桔长势、果实可溶性固形物也没有显著改变。说明施用有机肥可以减少柑桔木虱和柑桔全爪螨的发生,而对柑桔树的长势、果品质量没有不利影响。     

果树生长发育、产量和果实品质对水分胁迫反应的敏感期及节水灌溉

本文综述国内外有关桃、苹果、柑桔、梨等果树的营养生长、开花座果、果实的生长发育和果实品质对水分胁迫反应的敏感时期方面的研究成果,提出了在果树生产需水的非关键时期进行节水灌溉的技术,并就这一技术在生产实际应用中应注意的问题进行了讨论。     

柑桔隔年结果的生理机制研究进展

柑桔隔年结果是世界上柑桔业的一大问题,严重影响了果实的产量和经济效益。该文对柑桔种类和品种、碳水化合物和氨基酸等代谢产物、核酸和核苷酸、矿质营养、激素、蛋白质及酶等影响柑桔成花和隔年结果的相关因素进行了评述,为今后的研究和生产提供参考依据。     

Recent Advances in the Regulation of Citric Acid Metabolism in Citrus Fruit

The regulation of citric acid metabolism during fruit ripening has a major impact on the production of high-quality fruit. The impact of citric acid on organoleptic fruit quality attributes, fruit storage performance and the synthesis of several secondary metabolites has led to an exponential increase in research efforts during the last two decades. Recent research has focused on the relationship among citric acid biosynthesis, transportation, storage, and utilization. Among citrate metabolic processes, activities of a proton pump, especially the plasma membrane H⁺-ATPase on tonoplast and citrate catabolism in cytosol play important roles in the regulation of citrate accumulation in cell vacuoles. Moreover, we highlight recent advances and provide an overview of citrate metabolism, postharvest physiology of citrate metabolism, and the influence of agro-climatic factors on citrus fruits. It is the first review that provides a comprehensive model for citrate metabolism in citrus fruit juice sacs. We anticipate that this model for the regulation of citrate metabolism will facilitate the study of fruit acidity in citrus and other nonclimacteric fruits.     

柑橘采后品质变化及保鲜技术研究进展

柑橘Citrus spp.是中国南方重要的热带、亚热带果树,其果实具有较高营养价值。然而,柑橘果实采后容易发生腐烂、失水、营养损失和病害,导致果实品质劣变,商品价值降低。本文就柑橘果实采后外观色泽,果实水分,果肉糖、酸、维生素C含量变化,果实病害青霉病、褐斑病、枯水病、油斑病发生,以及低温贮藏、热处理、短波紫外线(UV-C)照射、化学保鲜剂、生物技术保鲜等保鲜技术的研究进展进行综述,为提高柑橘保鲜效果、保持柑橘果实采后品质、延长果实保鲜期提供科学依据与生产实践指导。     

A Dark Incubation Period Is Important for Agrobacterium-Mediated Transformation of Mature Internode Explants of Sweet Orange,Grapefruit, Citron,and a Citrange Rootstock

Background

Citrus has an extended juvenile phase and trees can take 2–20 years to transition to the adult reproductive phase and produce fruit. For citrus variety development this substantially prolongs the time before adult traits, such as fruit yield and quality, can be evaluated. Methods to transform tissue from mature citrus trees would shorten the evaluation period via the direct production of adult phase transgenic citrus trees.

Methodology/Principal Findings

Factors important for promoting shoot regeneration from internode explants from adult phase citrus trees were identified and included a dark incubation period and the use of the cytokinin zeatin riboside. Transgenic trees were produced from four citrus types including sweet orange, citron, grapefruit, and a trifoliate hybrid using the identified factors and factor settings.

Significance

The critical importance of a dark incubation period for shoot regeneration was established. These results confirm previous reports on the feasibility of transforming mature tissue from sweet orange and are the first to document the transformation of mature tissue from grapefruit, citron, and a trifoliate hybrid.     

柑橘属光合作用的环境调节

光合机构的运转受环境影响很大,与柑橘的生长发育、产量和品质密切相关.结合我们的工作,综合论述了柑橘光合作用环境调节的研究进展.强光和紫外光导致光合作用下降与PSⅡ反应中心失活有关,光呼吸和叶黄素循环对光合机构有保护作用.温度胁迫下,光合作用下降主要是RuBPCase活性下降和PSⅡ反应中心失活引起,品种间存在差异.轻度水分胁迫引起的光合作用下降是气孔限制的结果,而严重水分胁迫导致光合作用的非气孔限制.提高CO₂浓度,能够促进柑橘的光合作用,进而促进柑橘的生长和提高其品质.阐述了N、P、S、Fe等矿质元素调节光合作用的机理及盐胁迫对光合作用的影响,指出了今后柑橘光合作用的研究方向.     

Genetic transformation and genes for resistance to abiotic and biotic stresses in Citrus and its related genera

Citrus is the most important tree fruit crop in the world. However, citrus production is affected by both biotic and abiotic stresses, including drought, extreme temperature, salinity, citrus canker, citrus tristeza virus, and Huanglongbing (or citrus greening), among others. These stresses can severely influence growth and development of both rootstocks and/or scions of citrus trees, thus reducing both fruit production and fruit quality. Modern advances in the tools of plant biotechnology and advances in genomics play important roles in understanding how citrus crops can cope with diseases and adverse environmental conditions. Within the last decades, much progress has been made in identifying and cloning of genes involved in resistance to biotic and abiotic stresses as well in genetic transformation of Citrus and its related genera, such as Poncirus trifoliata and Fortunella spp. In this review, we will provide information on advances and insights on genetic transformation protocols as well as availability of characterized genes involved in resistance to both abiotic and biotic stresses. This will be followed with a discussion on perspectives of future developments in this field.