Molecular Phylogenetic Diversity and Biological Characterization of Diaporthe Species Associated with Leaf Spots of Camellia sinensis in Taiwan.

Hiran A Ariyawansa,Patchareeya Withee,Nakarin Suwannarach,Shiou-Ruei Lin,Medsaii Tanjira,Jian-Yuan Wang,Jaturong Kumla,Ratchadawan Cheewangkoon,Ichen Tsai,Abdallah M Elgorban

doi:10.3390/plants10071434

Abstract

Camellia sinensis is one of the major crops grown in Taiwan and has been widely cultivated around the island. Tea leaves are prone to various fungal infections, and leaf spot is considered one of the major diseases in Taiwan tea fields. As part of a survey on fungal species causing leaf spots on tea leaves in Taiwan, 19 fungal strains morphologically similar to the genus Diaporthe were collected. ITS (internal transcribed spacer), tef1-α (translation elongation factor 1-α), tub2 (beta-tubulin), and cal (calmodulin) gene regions were used to construct phylogenetic trees and determine the evolutionary relationships among the collected strains. In total, six Diaporthe species, including one new species, Diaporthe hsinchuensis, were identified as linked with leaf spot of C. sinensis in Taiwan based on both phenotypic characters and phylogeny. These species were further characterized in terms of their pathogenicity, temperature, and pH requirements under laboratory conditions. Diaporthe tulliensis, D. passiflorae, and D. perseae were isolated from C. sinensis for the first time. Furthermore, pathogenicity tests revealed that, with wound inoculation, only D. hongkongensis was pathogenic on tea leaves. This investigation delivers the first assessment of Diaporthe taxa related to leaf spots on tea in Taiwan.

Highlights

Species of Diaporthe have been frequently reported as pathogens, endophytes, and saprobes of various types of hosts [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17]
The aim of this study was to fully characterize the diversity and phylogeny of Diaporthe-like strains originally isolated from the leaf spots of C. sinensis and evaluate their pathogenicity to the major tea cultivar Chin-Shin Oolong grown in Taiwan’s tea fields
19 Diaporthe-like strains associated with leaf spots of C. sinensis were isolated from five different tea fields located in Taiwan (Figure 1 and Table S1)

Summary

Introduction

Species of Diaporthe have been frequently reported as pathogens, endophytes, and saprobes of various types of hosts [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17] These taxa have been reported globally and cause various diseases on economically important plants and crops such as dieback of forest trees [2], leaf spots on tea and Ixora spp. Multilocus phylogenies based on DNA sequences of ITS (internal transcribed spacer), tef1-α (translation elongation factor 1-α), tub (beta-tubulin), and cal (calmodulin) are more often used to determine the natural classification of Diaporthe species [1,26,29,30,31]

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Conclusion