First Report of Fusarium striatum Causing Root Rot Disease of Panax notoginseng in Yunnan,China

摘要

Panax notoginseng is a traditional Chinese medicinal plant.Root rot of P.notoginseng is one of the most serious diseases affecting P.notoginseng growth and causes wilted leaves,fewer lateral roots and rotten roots.Root rot is a soil-borne disease,and mainly occurs from June to August in Yunnan Province when the temperatures are high and the air is humid.In this study,the endophytic fungal genus Fusarium isolate E-2018.1.22-#3.2 was obtained from a P.notoginseng embryo.Fusarium isolate E-2018.1.22-#3.2 was identified as Fusarium striatum based on morphological characteristics and molecular analysis.The fungus was found to have conidiophores and macroconidia,and its ITS,LSU and TEF-1αgenes shared 100%,99.2%and 99%identities with the homologous genes of Fusarium striatum,respectively.Isolate F.striatum E-2018.1.22-#3.2 can cause root rot symptoms,including black,soft roots,fewer lateral roots and leaf wilt,in 93%of the experimental P.notoginseng plants,and could be re-isolated,fulfilling Koch’s postulates.When the P.notoginseng plants were treated with the fungicide pyraclostrobin,isolate F.striatum E-2018.1.22-#3.2 was unable to cause root rot.We have therefore demonstrated that F.striatum E-2018.1.22-#3.2 is able to cause root rot disease in P.notoginseng.This is the first report of root rot disease caused by F.striatum on P.notoginseng in China.