Current Status of Fungi Associated with Strawberry (FragariaXananassa Duch.) Dry Wilt in Guanajuato, Mexico
Strawberry dry wilt (FragariaXananassa Duch.) is the main disease in this crop at the state of Guanajuato, Mexico. It causes losses of up to 7.5 Mg ha-1 (50 % of the production). In Guanajuato this disease is associated with 14 fungi species, Fusarium oxysporum is the most common. The objective of this study was to assess the presence and current fungi frequency and identify other species associated with the disease. For which, plants with typical symptoms of the disease from 34 commercial plots were analyzed during the spring-summer cycles 2014 and 2015. The fungi identification was made by cultural and morphological characterization and sequencing amplification of transcribed spacer region (ITS) characteristics. Fungi from the Fusarium, Alternaria and Rhizoctonia genera had frequencies of 54, 36 and 11 % from 511 pure isolates obtained in 2014; and 60, 29 and 11 % from 833 pure isolates in 2015. ITS comparison identified F. oxysporum and F. verticillioides; in addition, F. proliferatum and four other species of this genus not previously reported in the crop. By culture and morphological characteristics, A. alternata was identified and isolated from root and crown damaged tissue. This is a new report from other species of Fusarium and Alternaria associated to strawberry dry wilt in Guanajuato, Mexico.