Total 69 isolates of Phytophthora nicotianae var. nicotianae were isolated and identified from tobacco black shank samples collected from different areas of Anhui province,and mating types of the oomycete were investigated by the method of partnership culture in vitro on L-tryptophan medium with β-sitosterol.The results showed that A2 mating type was the predominant in isolates of P.nicotianae var.nicotianae,next was A0 mating type,A1 and other mating types were not observed.It was suggested that sexual reproduction of P.nicotianae var.nicotianae might not take place frequently,and Anhui province might not be the original center of P.nicotianae var.nicotianae.The results indicated further that mating type geographical distribution of P.nicotianae var.nicotianae in Anhui province was in line with that in China.In addition,the significance of the test results and the possible reason for A1 mating type being absent were discussed.
