作　　者： ; ;

机构地区： 华南农业大学植保系

出　　处： 《华南农业大学学报》 1993年第2期61-67,共7页

摘　　要： 黄瓜叶片气孔密度、总糖含量与黄瓜品种对霜霉病的抗性负相关。黄瓜霜霉病菌的侵入需通过叶片发育成熟的气孔。气孔大小、还原糖含量和过氧化物酶(PO)活性与黄瓜品种对霜霉病的抗性无关。接种霜霉病菌后,不同品种PO酶活性均在症状出现时期开始上升且感病品种PO酶活性上升高于中感和抗病品种。蛋白质含量、多酚氧化酶(PPO)活性与黄瓜品种对霜霉病的抗性正相关。接种发病后,抗病和感病品种PPO酶活性均上升,抗病品种上升高于感病品种。在健叶中,抗病品种超氧物歧化酶(SOD)活性高于感病品种;病叶中SOD酶活性降低。接种后刚显症时,抗病、感病品种SOD酶活性均上升且感病品种的酶活性高于抗病品种;发病后期,酶活性下降。 丝瓜与霜霉病组合中PPO酶活性的变化和黄瓜与霜霉病组合中的变化相类似。 The number of stomata and total sugar content of cucumber cultivars were negatively correlated to the resistance to downy mildew [Pseudopernospora adbensis(Berk. et Cult. ]. The pathogen of the disease penetrated mainly through the well developed stomata.The size of stomata, the amount of reducing sugar content and peroxidase(po) activity had no correlation with the resistance of the plant to the disease. After inoculation with the pathogen all cultivars showed an increase of PO activity at the time of symptom expression,with higher increase in the susceptible cultivars than in the moderately resistance and resistant ones. The protein content and polyphenoloxidase(ppo) activity were positively correlated to the resistance of the plant. After the development of the disease by inoculation, the PPO activity increased in both susceptible and resistant cultivars, with higher activity in the latter than the former. In the healthy leaves,higher activity of superoxide dismmase(SOD)was found in the resistant culrivar than the susceptible ones, while in the infected leaves,its activity was reduced. After inoculation,SOD activity was found, to increase in both susceptible and resistant cultivars during the expression of the symptoms,with higher activity in the susceptible cultivar than the resistant one. SOD activity decreased in the late stage of the disease development. Riugegourd was found to have a same changing pattern of PPO activity as cucumber in relation to the degree of resistance to the downy mildew.

关 键 词： 黄瓜 品种 霜霉病 抗病性

领　　域： [农业科学] [农业科学]