A morphological and molecular reassessment of fungi associated with gray blight complex of tea: four new Pseudopestalotiopsis species from Sri Lanka

Authors: WEERASEKARA, INAKSHIKA - University Of Sri Jayewardenepura; UDAYANGA, DHANUSHKA - University Of Sri Jayewardenepura; MANAMGODA, DIMUTHU - University Of Sri Jayewardenepura; MAPA, SUMUDU - University Of Sri Jayewardenepura; SINNIAH, GANGA - University Of Sri Jayewardenepura; Castlebury, Lisa

Submitted to: Mycological Progress
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/22/2024
Publication Date: N/A
Citation: N/A

Interpretive Summary: Tea is an important crop in several Asian countries and integral to many people's morning or evening routines around the world. Global production is expected to be in excess of 8 million tons and is valued in billions of dollars. Many fungi cause diseases on tea plants, including a complex of species known as Pestalotia that are implicated in a disease call gray blight. These fungi are very difficult to identify as many have overlapping features. This study used a combination of spore characters and DNA to solve problems with the identification of fungi causing this disease on tea in Sri Lanka. Seven species were found to be contributing to disease problems, including four newly named species. This information will be useful to plant pathologists, tea producers and others involved in the management of diseases in tea plants everywhere this important crop is grown.

Technical Abstract: Tea [Camellia sinensis (L.) O. Kuntze] is a major commercially important crop cultivated in both tropical and subtropical areas for the production of the famous beverage “tea”. Gray blight is one of the most commonly encountered foliar fungal disease caused by Pestalotiopsis-like taxa. In this study, a fresh collection of fungi isolated from symptomatic tea leaves were characterized based on morphological and molecular data. A combined phylogenetic analysis of ITS, TUB and tef-1a revealed the occurrence of multiple species Pseudopestalotiopsis associated with gray blight in Sri Lanka. Among them, the previously known species Ps. dawaina, Ps. annellata and Ps. Chinensis were identified with reference to the ex-type isolates. Additionally, four new species of Pseudopestalotiopsis viz. Ps. lankensis, Ps. petchii, Ps. ratnapurensis and Ps. rossmaniae are newly described with full descriptions and illustrations. Since immature leaves and buds of tea plants are used in manufacturing tea, prevention of the occurrence of foliar diseases is utmost important to minimize annual yield losses. Hence it is necessary to investigate the diversity and distribution of the causal agents of this disease and the extent of pathogenicity in order to implement effective disease management measures.