STUDIES ON FUSARIUM WILT OF JOJOBA(SIMMONDSIA CHINENSIS)-A NEW DISEASE IN CHINA Ⅰ.Identi Fication and Pathogenicity of the Pathogens

A wilt disease of Jojoba(Simmondsia chinensis(Link) Schneider) was found occurring at several experimental plots of Jojoba in Yunnan Province.During 1987~1990,46 diseased Jojoba plants that were 3~6 years old were collected from seven experimental plots of Jojoba in Yunnan.Fusarium spp.were frequently isolated from the roots of the diseased Jojoba plants(by PDA or PSA medium).According to the studies on their culture,morphology and pathogenicity,they were identified as Fusarium oxysporum,F.solani,F.equiseti and F.moniliforme.Among them F.oxysporum predominated over the other three Fusarium species in distribution and quantity,and it was proved to be the most virulent,therefore it was considered as the main pathogen to cause the wilt disease of Jojoba in Yunnan.