【作者】 于业志；

【导师】 李德全； 陈振德；

【作者基本信息】 山东农业大学 ， 植物学， 2007， 硕士

【摘要】 本试验运用比较生理学方法,以抗小黑点病不同的大白菜品种为材料,研究了氮素形态对大白菜小黑点病和抗病性相关生理指标的影响,以及同一氮素形态不同氮素用量下,大白菜抗、感小黑点病品种保护酶(SOD﹑POD﹑PPO)活性及酚类物质含量及代谢的变化与大白菜抗感小黑点病的关系。主要结果如下:(1)大白菜小黑点的发生受氮素形态﹑作物基因型等共同作用的影响,施硝态氮可减轻小黑点病的发生。硝态氮处理和铵态氮处理下的各指标较有规律性,而酰胺态氮处理下的各指标则稍有波动,不同形态氮素对大白菜不同部位的部分效应相反。(2)小黑点病主要发生在生育中后期,且多先发于老叶正面,不同品种黑点在叶柄上发生分布的部位不同,较高的氮素水平明显可以加重感病品种病情。不论在施氮还是不施氮条件下,抗病和感病品种苗期叶柄中SOD﹑POD﹑PPO酶活性以及酚类物质含量存在明显差异,表现为感病品种高于抗病品种,仅POD酶活性反之,表现为抗病品种高于感病品种;各生理指标在莲座期和包心初期规律性不太明显,生育后期尤其在收获期抗病品种叶柄中SOD活性、酚类物质含量明显低于感病品种,而抗病品种叶柄中MDA含量、POD、PPO活性却明显高于感病品种。叶片中保护酶活性以及酚类物质含量的变化规律性不如叶柄中明显。(3)不论叶柄还是叶片中抗病品种的各项生理指标在整个生育期内处理与对照相比差异变化较小,而感病品种处理与对照的差异变化相对来说较大。说明抗病品种自我调节和恢复正常状态的能力比感病品种强。此结果可作为苗期抗病生理选种与鉴定的参考生理指标。(4)在整个生育期内对酚类物质含量的变化及其与大白菜抗感小黑点病的关系实验结果表明:抗感品种间各物质含量在莲座期的差异表现比较明显,而在莲座期,差异最明显的是叶片中绿原酸的含量,对于品种的抗病性更具有代表性,其次是叶片中咖啡酸和叶柄中没食子酸的含量。绿原酸的积累在大白菜抗小黑点病过程中具有极其重要的意义。综上所述,保护酶(SOD﹑POD﹑PPO)活性以及酚类物质含量及代谢的变化均与大白菜抗小黑点病性有关,可作为大白菜抗小黑点病生理选种特别是在早期选种的生理指标或参考指标。对加速选育进程、提高选育质量有重要意义。更多还原

【Abstract】 Chinese cabbage varieties with different resistances to petiole spot were used as materials. By comparative physiology method, we studied the effect of nitrogen forms on the physiological metabolism resisted to petiole spot disease of Chinese cabbage , and the relationship of Superoxide dismutase (SOD) activity, Peroxidase (POD) activity, Polyphenoloxidase(PPO) activity, phenolics content. The results showed:(1) Both different nitrogen forms and different Chinese cabbage gene types could affect petiole spot of Chinese cabbage, when nitrate nitrogen was used as nitrogen source, the disease index lowed. and there’s a remarkable rhythm between the application of ammonium nitrogen and nitrate nitrogen, except there’s a bit alteration under amide nitrogen to physiological metabolism. What’s more, some physiological and biochemical indexes in petiole were opposite to those in leaf blade under different nitrogen forms.(2) Petiole spot symptoms mostly occurred on the filed of outer leaf blade in the harvest stage, it appeared on different spots to different Chinese cabbage varieties. And susceptible variety had a more serious disease under higher nitrogen level. The phenol content, SOD and PPO activities in leaf petiole of the susceptible Chinese cabbage variety to petiole spot were all higher than the resistant one evidently, wherever under nitrogen treated or non - nitrogen treated in the seedling stage. On the contrary, POD activity of the resistant variety was lower than that of the susceptible one. What’s more, SOD activity and the phenol content of resistant variety were lower than those of susceptible variety , and MDA content、POD and PPO activities of resistant variety were all higher than those of susceptible variety significantly during the later growth stage, especially harvesting stage. However, the difference in leaf blade wasn’t remarkable.(3) The study also indicated that the capacities of self-regulating and returning to normal status of resistant variety were stronger than susceptible one. The results can be used as the physiological indexes to breeding and identification of resistance to petiole spot in the seedling stage of Chinese cabbage.(4) During the whole growing period, the differences of every phenol ingredient content were obvious for resistant cabbage variety and susceptible one in lotus period, and during this time, the most different was the content of Chlorogenic acid in leaf blade, then Caffeic acid in leaf blade and Gallic acid in petiole. And Chlorogenic acid played an important part in resisting petiole spot of Chinese cabbage.As mentioned above, the changes of protective enzymes activities (SOD﹑POD﹑PPO)and phenol content and metabolism were all related with the resistance to petiole spot of Chinese cabbage, they can be used as physiological indexes or referenced targets of the physiological seed selecting of the Chinese cabbage especially in former stage. It’s important to accelerating process of seed selecting and breeding and increasing the quality of seeds.更多还原