Abstract: Total sixty-nine Phytophthora nicotianae Breda de Haan var. nicotianae Waterhouse isolates were obtained from diseased tobacco stem tissue collected from 10 different localities in Anhui, which Bozhou, Guoyang, Xuxian, Taihe, Lixin, Guzhen, Fengyang, Hefei, Shexian and Wuhu. The main culture character of theses sixty-nine isolates were studied via sporangia abduction, partnership culture in vitro, growth properties mensuration, et al, results showed that these Phytophthora nicotianae Breda de Haan var. nicotianae Waterhouse were heterothallic, with amphigynous antheridia and small oogonia, able to produce oosopora when partnership culture with standard mating type isolates in vitro, and that sporangia were mostly spherical or approximatively spherical, with short caduceus and conspicuously papillate (single or double), easily falling off, and attached some diverse length mycelia-like silk. The asymmetry shape sporangia appeared frequently. The optimum temperature for mycelial growth in vitro was between 20℃ to 30℃, the maximum beyond 35℃ and below 40℃, and the minimum beyond 8℃ and below 10℃.

Key words: Tobacco blank shank, Phytophthora nicotianae var. nicotianae, Culture character, Morphology, Heterothallic