Mexican periwinkle virescence phytoplasma associated with phyllody and virescence in strawberry (Fragaria x ananassa Duch.) in Michoacan, Mexico

Abstract

The strawberry phyllody is considered a reversion of floral reproductive organs, such as achenes in vegetative structures, which can be infectious and non-infectious. The objective of this research was to determine the regional distribution and incidence of phyllody in two strawberry growing areas in Michoacan, Mexico and to determine whether these symptoms are associated with the presence of phytoplasmas. The study comprised 51 strawberry plots distributed in the municipalities of Zamora, Jacona, Tangancicuaro, Chilchota and Maravatio, during the production season, 2014–2015. Phyllody incidence was estimated in 40 plants per plot (five sampling points, eight plants each) distributed approximately equidistant in a zig-zag scheme. Twenty-eight of these samples were used to run a nested PCR protocol for phytoplasma detection; primers P1/P7 were used to amplify a fragment of approximately 1800 bp, and primers P1A/ 16S SR were used to amplify a fragment of approximately 1500 bp, in the first and second reactions, respectively. The strawberry phyllody was found widely distributed with incidence levels up to 35 %. These symptoms were associated with the presence of Mexican Periwinkle Virescence Phytoplasma (MPV). This report is the first to describe this phytoplasma in strawberry in Mexico in the municipalities of Zamora, Jacona, Tangancicuaro, Chilchota and Maravatio in the state of Michoacan. The results will be used to design strategies for managing the disease in commercial nurseries and commercial plantings of strawberry.