黑龙江省大豆镰孢根腐病菌鉴定及致病力分析

Identification and virulence of Fusarium spp.causing soybean root rot in Heilongjiang Province

对黑龙江省不同区域采集的大豆根腐病病原种类进行鉴定,结果表明:分离的296个真菌分离物分属于10个种,分别为尖镰孢(Fusarium oxysporum)、茄镰孢(F.solani)、木贼镰孢(F.equiseti)、轮枝镰孢(F.verticillioides)、半裸镰孢(F.semitectum)、大豆拟茎点种腐病菌(Phomopsis longicolla)、瓜果腐霉(Pythium aphanidematum)、茄丝核菌(Rhizoctonia solani)、禾谷镰孢(F.graminearum)、厚垣镰孢(F.chlamydosporum),各分离物分离频率分别为68.24%、7.09%、5.41%、4.05%、3.38%、3.38%、3.04%、2.70%、2.03%和0.68%。利用‘合丰25’测定所有镰孢菌分离物的致病力,病情指数在30以上的分离物占镰孢菌总数的23.42%,其中尖镰孢为18.22%。在中等以上(病情指数>30)致病力镰孢菌分离物中,尖镰孢占77.78%。黑龙江省不同地理区域均有致病力较强的分离物,分布不均匀。大豆花芽分化期分离的致病力较强,尖镰孢出现频率比鼓粒期大。本研究为大豆根腐病的田间防治和抗源筛选的研究奠定了基础。

The pathogens causing soybean root rot in Heilongjiang Province were identified.Totally,296 fungal isolates were isolated from diseased plants collected from Harbin,Jiamus,Heihe,Qiqihaer,and Jixi regions,and these isolates were identified as 10 fungal species,Fusarium oxysporum,F.solani,F.equiseti,F.verticillioides,F.semitectum,Phomopsis longicolla,Pythium aphanidemnatum,Rhizoctonia solani,F.graminearum,F.chlamydosporum,and the proportion was 68.24%,7.09%,5.41%,4.05%,3.38%,3.38%,3.04%,2.70%,2.03% and 0.68%,respectively.Virulence test of the Fusarium isolates showed that 23.42% isolates were moderately or highly virulent to soybean variety.＇ Hefeng 25 ＇,with disease index of over 30 and F.oxysporum occupied for 18.22%.Among those isolates with disease index of over 30,F.oxysporum occupied for 77.78%.The high virulent isolates were found in different geographic regions with uneven distribution in Heilongjiang Province.The higher virulent isolates from soybean ＇ Hefeng 25＇ at flower bud differentiation period occupied higher proportion than those at seed filling stage.This study laid a foundation for field control and resistant variety screening to soybean root rot.