Identification of Fusarium Species Associated with Fusarium wilt Disease of Strawberry in Zhejiang Province, China.

Abstract

Strawberry Fusarium wilt, caused by Fusarium spp. is one of the most devastating diseases threatening the Chinese strawberry industry. In this study, 64 representative Fusarium strains were isolated from diseased crowns and petioles of strawberry plants cultivated in six key production areas across Zhejiang Province, where disease incidence ranged from 30% to 50% from July to December. Morphological characterization, multi-locus phylogenetic analysis, and pathogenicity tests identified these strains as three distinct species: Fusarium oxysporum f. sp. fragariae (Fof) (48 strains, 75%) in the Fusarium oxysporum species complex (FOSC), Fusarium luffae (9 strains, 14.06%) in the Fusarium incarnatum-equiseti species complex (FIESC), and Fusarium commune (7 strains, 10.94%) in the Fusarium nisikadoi species complex (FNSC). Among these species, Fof was dominant, the fastest colony growth at temperatures above 28 ℃. Pathogenicity tests revealed that Fof isolates resulted in the highest disease severity, followed by F. commune. This study presents the first report of Fof as a causal agent of strawberry Fusarium wilt in Zhejiang, China, and of F. luffae causing Fusarium wilt of strawberry worldwide. The identification and pathogenicity characterization of Fusarium species causing strawberry wilt provides valuable information for the effective management of the disease in China.