Preliminary Study Of Fungal Endophytes Of Tobacco In YunNan

Fresh tobacco samples were collected from the main areas in Yunnanfrom August, 2002 to September, 2003 for the isolation of fungal endophytes.The best culture isolation method was established with the help of surfacesterilization efficacy check. The duration of sodium hypochloride treatment isthe most important among all the parameters, different duration should bechosen according to different tobacco tissues in different growth phases to getas more isolates as possible with the guarantee of efficient surface sterilization.Most of the 186 isolates did not sporulate under ordinary conditions. Specialmethods were needed to induce sporulation, ultraviolet radiation and additionof tobacco tissues into culture medium were useful to induce sporulation. 10species were identified from 70 sporulated isolates. They are Phyllachoranicotiae W. Han sp. nov., Phyllachora nicoticola W. Han sp. nov., Glomerellaacutata J. C. Guerber & J. C. Correll, Pestalotiopsis nicotiae W. Han sp.nov.,Phoma epicoccina Punithalingam, Tulloch & Leach, Phoma pomorum Th?m,Fusarium moniliforme Sheld. var. minus Wollenw. & Reinking, Nigrosporasphaerica (Sacc.) Mason, Alternaria brassicicola (Schw.) Wiltshire, Alternariacitri Ellis et Pierce. Phyllachora nicotiae W. Han sp. nov., Phyllachoranicoticola W. Han sp. nov., Pestalotiopsis nicotiae W. Han sp.nov. are newspecies. Glomerella acutata J. C. Guerber & J. C. Correll, Phoma epicoccinaPunithalingam, Tulloch & Leach, Phoma pomorum Th?m are Chinese newrecord species. 24% isolates are Alternaria citri, it exists during the whole growth oftobacco in all sampling areas. Phyllachora nicotiae and Phyllachora nicoticolawere only isolated from leaf; Phoma epicoccina and Phoma pomorum wereonly isolated from stem. These 4 species have tissue speciality with regard totheir special biological characteristics. The fungal endophytes populationincreases during tobacco growth, there are the most population and species offungal endophytes when leafs mature. There are no enough proof to testifywhether variety-level host speciality exists.