【摘要】 本文选用以CO39为背景的水稻近等基因系与广东省稻瘟病菌3个优势生理小种(ZC13、ZB1和ZB5)构成12个亲和性和非亲和性互作组合,组建各组合稻瘟病菌的生命表和繁殖表,分析在亲和性互作中稻瘟病菌的生存和繁殖状况对寄主发病的影响,并探讨在非亲和性互作中抗性基因在抵御病菌侵染过程中的作用。结果表明,在亲和性和非亲和性互作中,稻瘟病菌生长繁殖各阶段均参与了感抗反应并发挥了一定的作用:在CO39近等基因系上,同一小种的孢子萌发率或菌丝形成率无明显差别,而小种间则表现一定差异;病菌的定殖和繁殖是亲和与非亲和互作的关键阶段,定殖率、病斑形成率低,则寄主表现抗病,反之则表现感病。在繁殖表众多表示种群增长的参数中,世代平均产孢量F’、净增殖率R0、最大相对增长率rmax和种群趋势指数Ⅰ等4个指标适合于反映稻瘟病菌繁殖状况与感抗病反应的关系。更多还原

【Abstract】 The near-isogenic lines (NILs) of rice with CO39 genetic background and three major physiological races (ZC13, ZEl and ZB5) of rice blast fungus, Magnaporthe grisea, occurring in Guangdong Province were used to establish the cohort life and reproductivity tables on twelve race X line combinations showing compatible and incompatible reactions. Survival and reproduction of the pathogen, as well as their effects on disease development were studied for the compatible combinations. The function of resistant genes against pathogen infection was also studied for the incompatible combinations. The result indicated that in compatible and incompatible combinations, each step from pathogen vegetative growth to reproduction may more or less involve susceptibility/resistance expressions of the host. In CO39 NILs, no difference in spore germination and hyphae growth rate among the tested spores of the same races was found. However, those among spores between the races were significantly different. The critical time points of expression of compatible or incompatible reaction were at the beginning of colonization and reproduction of the pathogen. Lower colonization rate and slower lesion formation related to expression of more resistance of the host. Among those in reproductivity table relating to population dynamics, four parameters, average sporulation per lesion per generation (F’), net reproduction rate (R0)> maximum relative growth rate (rmax) and index of population trend (I). were more applicable to reflect the relationship between the reproductive status of M. grisea and expression of susceptibility/resistance of the host.更多还原