Molecular characterizations of Verticillium dahliae isolates from grafted tomatoes grown in Antalya province of Türkiye

Abstract

Verticillium wilt caused by soil-borne fungus Verticillium dahliae results in serious quality, yield and economic losses in tomato fruit production in tomato-growing areas around the world. In this study, V. dahliae isolates obtained from six different major grafted tomato production areas in Antalya province of Turkiye were characterized for races, pathotypes and vegetative compatibility groups using the specific PCR primers. Out of 66 isolates, 60 were determined to be race 2. Six isolates were not identified as race 1 or race 2. Fifty-six isolates were determined as defoliating pathotypes (D) while 10 isolates were identified as non-defoliating (ND) pathotypes. The isolates were clustered into four vegetative compatibility groups (VCGs): VCG1A (61), VCG2A or VCG4B (3), VCG2B (1) and VCG6 (1). According to the results of this study, the race 2, D pathotype and VCG1A isolates were dominant and widely distributed in the region. Additionally, the V. dahliae isolates fall into two major groups based on the dendrogram constructed from molecular data by Dice similarity index. The dendrogram showed significant diversity among the V. dahliae isolates particularly in the Elmali region compared to other regions. The study is the first comprehensive research with the current disease and race 2 was identified for the first time in grafted tomatoes. These findings will lead to the development of V. dahliae-resistant grafted tomatoes and breeding programs in Turkiye.