花椰菜幼苗抗黑腐病的生理机制研究

以对黑腐病抗性不同的2个花椰菜(B rassica oleracea var.botry tis)品种为材料,研究了花椰菜苗期抵抗黑腐病的生理机制。结果表明:接种7 d后,黑腐病菌(X anthom onas camp estris pv.C amp estris)的侵入导致花椰菜幼苗干物质积累下降,抗病品种‘雪峰’的下降幅度明显低于感病品种‘2003X-106’,这与接种3 d后雪峰的净光合速率、气孔导度、蒸腾速率和叶绿素含量等下降较慢有关。病原菌侵染后,2个品种叶片的可溶性糖含量均有增加,但是抗病品种‘雪峰’的增幅较感病品种‘2003X-106’低;‘雪峰’叶片的可溶性蛋白质含量在接种后逐渐降低,而‘2003X-106’却逐渐增加;接种后,‘雪峰’叶片的IAA和M e-JA含量均上升,ABA则显著降低,而‘2003X-106’的IAA含量降低,ABA显著增加,M e-JA则在接种后的不同时期有增有减。

Physiological Mechanism of Brassica oleracea var. botrytis Seedlings to Resist Black Rot

Two Brassica oleracea var.botrytis varieties with different resistances to black rot were used to study physiological mechanism of Brassica oleracea var.botrytis seedlings to resist black rot.The results showed that Xanthomonas campestris pv.Campestris infection decreased dry matter accumulation in Brassica oleracea var.botrytis seedlings seven days after Xanthomonas campestris pv.Campestris inoculation,and the decrement in resistant Xuefeng was remarkably lower than that in susceptible 2003X-106,which was related to the decreased photosynthetic rate,stomatal conductance and chlorophyll content of Xuefeng.After the infection of the pathogen,the two varieties both increased soluble sugar content in their leaves,and the increment in resistant Xuefeng was lower than that in susceptible 2003X-106.After inoculation,Xuefeng gradually decreased soluble protein content in its leaves,but 2003X-106 gradually increased the soluble protein content in its leaves.After inoculation,the leaves of Xuefeng appeared to rise in IAA and Me-JA contents and declined significantly in ABA content,but the leaves of 2003X-106 decreased in IAA content and significantly increased in ABA content,fluctuated in Me-JA content.