【作者】 李琴；

【导师】 张日清； 王贵禧；

【作者基本信息】 中南林业科技大学 ， 森林培育， 2010， 硕士

【摘要】 冬枣(Zizyphus jujuba Mill.cv. Dongzao),是我国特有的晚熟枣品种,因果实鲜食品质极优而被推崇为果中珍品,极具经济效益。枣锈病(Phakopsora ziziyiphi-vulgaris (P.Henn.) Diet.)是冬枣的三大病害之一,发生后不易控制,造成枣果严重减产及品质下降。目前关于枣锈病的研究仅停留在流行规律和药剂防治上。本试验通过研究叶片结构的差异性、冬枣不同病程叶片的防御酶系以及几种抗性物质的动态变化,为冬枣抗锈病品种的选育提供理论依据。研究结果如下：1.对冬枣3种不同叶龄的叶片进行锈病接种试验,并对叶片组织解剖结构进行了测定。结果表明：3种叶龄叶片感病程度由高到低依次为：嫩叶>长成叶>成熟叶,成熟叶对锈病的抵抗力最强；筛选出叶片角质层厚度,下表皮厚度,栅海比,叶片结构疏松度,气孔密度等指标与冬枣叶片对锈病的敏感程度有关,为抗锈病冬枣优良单株的筛选提供了理论依据。2.对冬枣、尜尜枣、灵宝大枣进行锈病接种试验,结果表明灵宝大枣抗锈病能力最强,尜尜枣次之,冬枣最弱。相对湿度、温度与锈病发生关系密切,当年7～8月气候条件不满足锈病孢子的高温高湿的侵染条件时,不要忽视锈病发生的可能性,9月份随着气温略微降低,相对湿度的增大有利于锈病的发生。3.扫描电镜观察发现枣锈病病原菌包括夏孢子和冬孢子阶段。夏孢子是双核菌丝体产生的成堆的双核孢子,革质,椭圆形或卵圆形,密生短刺萌发后,一般从气孔侵入寄主。本研究认为锈菌冬孢子可能也会在寄主表面萌发产生一个生长的短芽管,继续萌发产生双核菌丝体形成夏孢子,夏孢子萌发继续反复侵染寄主植物。4.将感病的冬枣叶片分为0级(未发病)～4级(整叶发病)5个级别,研究不同病程叶片的防御酶活性以及相关成份的变化,结果表明：SOD、POD、CAT、PPO、PAL可溶性总糖、可溶性蛋白、O2·-产生速率、H2O2、丙二醛、酚类物质、叶绿素含量在受侵染过程中发生不同的变化,除PAL活性外,各病程间差异显著或极显著。初步筛选出SOD、POD、CAT、O2-、H2O2、MDA、酚类物质、可溶性总糖、可溶性蛋白和叶绿素为冬枣锈病病程相关指标。更多还原

【Abstract】 Zizyphus jujuba Mill. cv. Dongzao is an endemic late-maturing jujube variety in China, and it is considered as the treasure of fruits because of the excellent quality of the fresh fruit. Jujube rust is one of the three important diseases difficult to control after occurrence and can cause a heavy loss in production and fruit quality. Present research on jujube rust has only dealt with the epidemiology and chemical control. In this study, the difference of leaf structure, change of defense enzymes, and resistant physiological indexes of different disease levels were studied in order to provide a theoretical basis for selective breeding in Z. jujuba Mill. cv. Dongzao in the aspect of generating varieties resistant to rust disease. The main results obtained are as follows:1. Rust inoculation experiment was conducted with three different-aged leaves, and the anatomic structure of leaves was observed. The results showed that the degree of rust susceptibility in leaves was in the ascending order of young leaves> fully-grown leaves> mature leaves. In other words, mature leaves had the strongest resistance to rust. The leaf morphological structure including the thickness of the cutin layer, lower epidermis, and leaf blade, the ratio of palisade tissue to spongy tissue, the porosity of leaf tissue structure, and the stoma density were correlated with jujube rust occurrence, and could be used as indicators for the control of jujube rust and for selecting rust-resistant plus trees in jujube ’Dongzao’.2. Rust inoculation experiment was conducted with Z. jujuba Mill. cv.Dongzao, Jujube Gaga, and Jujube Lingbao,and the results showed that Jujube Lingbao had the strongest ability to resist rust disease, Jujube Gaga ranked next, and Z. jujuba Mill. cv. Dongzao had the weakest resistance. Relative humidity and temperature correlated highly with the occurrence of rust disease. The weather condition could not meet the germination of rust pathogen in July and August of the year; however, we should not neglect the possibility of the occurrence of rust disease, because the slightly decrease in temperature and increase in relative humidity can induce the occurrence of rust disease.3. Scanning electron microscope showed that pathogens of Jujube rust included the stages of urediniospore and teliospore. Urediniospores are piles of dual-core spores produced by dual-core mycelium with leathery, oval-shaped or oval, dense and short thorn, and normally invade host plants from the stomata after germination. This study suggests that in the host surface teliospore may also produce a short germ tube, continue to produce dual-core mycelium which germinated to form urediniospores, then urediniospores germinate and infect host plants repeatedly. 4. According to various degrees of infection, rust degrees of leaves can be divided into degree 0 (no disease on leaf) to degree 4 (fully infected on leaf). The influences of rust induced by Phakopsora ziziphi-zulgaris(P. Henn) Diet on the activities of antioxidate enzyme and contents of relative physiological indexes were studied with leaves of Z. jujuba Mill. cv. Dongzao in this paper. The results showed that, SOD, POD, CAT, PPO, PAL, soluble sugars, soluble proteins, the rate of O2-, H2O2, MDA, phenols, and chlorophyll had different changes during the infection process. Except the PAL activity, there was significant or very significant difference among different disease levels. The results suggest that SOD, POD, CAT, O2-, H2O2, MDA, Phenols, soluble suger, soluble protain, and Chlorophyll can act as ralative indicators of rust occurrence in Z. jujuba Mill. cv. Dongzao.更多还原