Characterization of the Populations of Botrytis cinerea Infecting Plastic Tunnel-Grown Strawberry and Tomato in the Hubei Province of China.

A total of 707 isolates of Botrytis were collected from plastic tunnel-grown strawberry and tomato in the Hubei province of China. They were identified based on the specific molecular markers. Diversity of the B. cinerea (Bc) isolates was evaluated by typing the transposable elements (Boty, Flipper) and the mating types (MAT1-1, MAT1-2), as well as by determining virulence on tobacco (Nicotiana benthamiana) and fenhexamid sensitivity in agar medium. The results showed that 706 isolates (99.9%) were Bc and 1 isolate (0.1%) was B. pseudocinerea. The Bc isolates (n = 706) were classified into four transposable element types, Vacuma (3.1%), Boty (9.6%), Flipper (18.4%), and Transposa (68.8%). The strawberry and tomato subpopulations of Bc had significantly different (P < 0.05) compositions of the four transposable element types. The overall ratio of MAT1-1 to MAT1-2 deviated from 1:1 (n = 706; P = 0.0002), and MAT1-2 (56.9%) predominated over MAT1-1 (43.1%). In 7 of 12 geographic subpopulations, the ratio of MAT1-1 to MAT1-2 matched 1:1; however, in the remaining five geographic subpopulations, the ratio of MAT1-1 to MAT1-2 did not match 1:1. Results of the biological characterizations showed that most Bc isolates were highly sensitive or sensitive to fenhexamid, and the majority of Bc isolates were highly virulent or virulent on tobacco. Moreover, the relationship between genetic diversity and biological characteristics was analyzed. The results achieved during this study are helpful for understanding of the populations of B. cinerea.