水稻穗褐变病主要病原菌侵染时期及致病力研究

Infection period and virulence of the main pathogens isolated from browning panicle of rice

为了解黑龙江省水稻穗褐变病主要病原菌侵染时期及致病性情况,分别于水稻破口期、扬花期、乳熟初期采用禾谷镰孢Fusarium graminearum、链格孢Alternaria alternata、稻黑孢Nigrospora oryzae、黑附球霉Epicoccum nigrum对水稻穗进行注射和喷雾接种。结果表明,4种病原菌在水稻破口后即可侵染稻穗使谷粒颖壳变褐。注射接种稻穗谷粒褐变重于喷雾接种。4种病原菌的致病力存在明显差异,禾谷镰孢致病力最强,链格孢的致病力弱于禾谷镰孢。

In order to understand the infection period and virulence of the main pathogens isolated from browning panicle of rice in Heilongjiang,Fusarium graminearum,Alternaria alternata,Nigrospora oryzae and Epicoccum nigrum were inoculated at the rupturing stage,flowering stage and the early milk-ripe stage of rice panicle by injecting and spraying conidia suspension.The results showed that the rice panicle could be infected by four pathogens and caused browning grain glumes at the rupturing stage.Injecting inoculation caused more serious browning grains than spraying inoculation.The virulence of four pathogens was obviously different.The virulence of F.graminearum was the strongest,followed by A.alternata,while that of N.oryzae and E.nigrum were weaker.