Diversity of sporulating rice endophytic fungi associated with Thai rice cultivars (Oryza sativa L.) cultivated in Suphanburi and Chainat Provinces, Thailand

Abstract

During the last 10 years, studies on endophytic fungal diversity in various plant host varieties have been investigated increasingly. However, very little empirical research focused on the diversity of sporulating rice endophytic fungi (SREF) associated with Thai rice cultivars (Oryza sativa L.) has been performed. The aim of the present study is to explore the SREF associated with Pathumthani 1 and Rice Department 47 rice cultivars using the culture-dependent method from selected sublocations in the Suphanburi and Chinat Provinces of Thailand. Two hundred forty-two SREFs were preliminarily identified based on their morphological traits, and the internal transcribed spacer (ITS) and large subunit (LSU) rRNA gene sequence similarity comparisons validated 21 species in 17 genera. The four most frequently isolated SREF species were Nigrospora oryzae, Curvularia lunata, Daldinia eschscholtzii, and Exserohilum sp.3. The results suggest that SREF abundance, richness, distribution, and communities are predominantly influenced by different tissue segment types, rice cultivars, collection areas, and collection times. Our results also provide an insight into SREF diversity and contribute to our basic knowledge of the relationship between fungal diversity and host/location origin.