Biological and molecular characterization of Lasiodiplodia theobromae causing dieback disease of strawberry in Thailand

Abstract

In Thailand, strawberry production is confined mainly to Chiang Mai and Chiang Rai Provinces, located in the mountainous northern region, where the cool climate from December to March permits production (Pipattanawong, 2015). Strawberry plants are highly susceptible to high temperatures due to the reduction of strawberry flower formation and fruit quality (Klamkowski & Treder, 2008). Moreover, higher temperatures generate a higher demand for water, creating water stress in plants during dry seasons (Moretti et al., 2010). Therefore, strawberry is often harvested in winter and spring, but not in summer (Yamasaki, 2013). The greenhouse cultivation of strawberry, which provides protection from rain, pathogens and insects, and which ensures an optimal temperature environment, can be carried out throughout the year (Shigeoki et al., 2017).To produce strawberry all year round, greenhouse cultivation with an evaporative cooling system is often used for strawberry cultivation in Thailand (Pipattanawong, 2015). Like all commercially cultivated fruits, strawberries face a number of threats. Common diseases include leaf scorch, leaf spot, leaf blight, powdery mildew and anthracnose (Pipattanawong, 2015).However, strawberry plants are especially susceptible to fungal pathogens which can affect almost all parts of strawberry (Maas, 2012), and the occurrence of several fungi that infect strawberry crowns and roots has given rise to concerns that production