Genetic diversity and population structure of Lasiodiplodia theobromae from different hosts in northeastern Brazil and Mexico

摘要

Lasiodiplodia theobromae is one of the most frequent fungal pathogens associated with dieback, gummosis, leaf spot, stem-end rot and fruit rot symptoms in cashew, mango, papaya and grapevine. In this study, the variation in the genetic diversity of 117 L. theobromae isolates from northeastern Brazil (n = 100) and Mexico (n = 17), which were collected from these four crops, was analysed using microsatellite markers. The results revealed low genetic diversity among L. theobromae populations and the existence of two genetic groups. All Mexican isolates were grouped with Brazilian isolates, suggesting a low level of differentiation between these populations. Furthermore, no evident host or climate-based population differentiation was observed for L. theobromae in Brazil. The populations studied were mostly clonal, but additional studies are needed to better understand the mode of reproduction of the pathogen. The low genetic diversity of L. theobromae populations in northeastern Brazil suggests that resistant cultivars could be used as a durable management strategy to reduce the impact of the diseases caused by this pathogen.