THE INITIAL STUDY ON LEAF SPOT DISEASE OF GOLDEN TEA CAUSED BY Phomopsis AT THE TAMDAO NATIONAL PARK

Abstract

The golden tea belongs to Camellia genus tree, it contains many important compounds for the human health. However, the growth and development of golden tea were affected by diseases. In this study, leaf spot disease was recorded in two species of yellow tea at the TamDao National Park. The results showed that the percentage of diseased plants in two species of Camellia tamdaoensis Ninh et Hakoda and Camellia phanii Hakoda & Ninh were 85.0 and 80.0% respectively. The typical symptom of the disease was the appearance of small brown or black spots, they scattered on the leaves, where the leaves were dried (necrotic). At severe disease spots, mycelium was clearly observed. Pathogenic fungi were isolated on PDA medium, mycelium was white and fast-growing. Spores were mound-shaped with glossy, bright, black in color. The ITS sequence of the fungal pathogen causing leaf spot disease was amplified, sequencing and characterized. Its length was 519 bp, its GC content was 52.22%. By analysis of identity value and the genetic relationship, the pathogenic fungus on the leaf of two golden tea species was Phomopsis sp. TD2.