Abstract：Grapevines (Vitis vinifera) are widely planted in China. Grape gray mold caused by Botrytis cinerea, is one of the most common diseases threating grape production. The aim of this work is to estimate the phenotypes and virulence variability of B. cinerea isolates from grapes of different viticulture climate zones in China. In this study, characters of 143 B. cinerea isolates, containing phenotype, growth rate and virulences to Red globe grape (V. vinifera cv. 'Redglobe'), Mare nipple grape (V. vinifera cv. 'Mare Nipple') and rape (Brassica campestris) leaves, were tested by applying wound inoculation with mycelial blocks. The results showed that there were two phenotypes, mycelial type and sclerotial type, accounting for 40.56% and 59.44% respectively. Six sub-mycelial-types containing M1, M2, M3, M4, M5, and M6, were found, and the number of M6 type isolates was more than that of other sub-mycelial-types. There were 5 sub-sclerotial-types containing S1, S2, S3, S4, and S6, and the number of S3 type isolates was more than that of other sub-sclerotial-types. The growth rate variation of 143 isolates was very high and ranged from 4.76 mm/d to 12.91 mm/d, and 3 levels were found by clustering analysis. All 143 isolates could successfully infect red globe grape and mare nipple grape, while virulence differentiation was very serious. The sizes of lesion area were 46.03~258.55 mm2 and 14.80~385.34 mm2 respectively, which were divided into 4 levels by clustering analysis. 62 of 65 isolates could successfully infect rape leaves, and the radius of the lesions was between 2.88 mm and 16.63 mm. The correlation analysis between test data containing phenotype and virulence, and isolates' information containing collection regions, viticulture climate zones and grape hosts was performed. The results indicated that there was no significantly correlation between the two indexes and geographical distance and host grapes, while there was a certain correlation between phenotype and viticulture climate zone. The virulence also had some correlation with viticulture climate zone. The correlational analysis among phenotype, growth rate, and virulence were performed. The results showed that there was the slightly positive correlation among isolates' virulences to red globe grape, mare nipple grape and rape. While no significant negative correlation between growth rate and virulence to Red globe grape, and significant positive correlation between growth rate and virulence to Mare nipple grape and rape were found. In addition, phenotype was not obviously related to growth rate and virulence. This study lays the foundation for analysis of molecular phylogeny to the new phenotype and researching the mechanism of virulence differentiation. The results of this study also provide some helpful basis for studying B. cinerea diversity and controlling B. cinerea effectively.
