Screening of tea cultivars tolerant to branch canker disease using histopathological studies

摘要

A glass house experiment was carried out for screening tea cultivars against Macrophoma theicola causing canker. One year old nursery plants Wz. TRF-1, UPASI-3, Yabukita, UPASI-6, TRF-2, CR-6017, UPASI-9, UPASI-17, UPASI-26, TRF-4 andTRI- 2025 were selected. This study revealed that TRF-1 (19.67+1.20) and UPASI-3 (21.00±1.53) showed more number of pycnidiospores productions and bigger size of canker.The lesion size was bigger in clones UPASI-3 (2.57±0.09) and TRF-1 (2.03±0.09) followed by Yabukita. These clones were categorized as highly susceptible. In CR-6017 (3.00±0.58), TRF-2 (1.67+0.67) and UPASI-6 (1.33±0.33) noticed less number of spore production in the epidermis layer of cell. The canker size was also recorded small in size.The tolerant clones of UPASI-9, UPAS-17, UPASI-26,TRF-4 and TRI-2025 were characterized by the absence of spore formation and below 1.0 cm of canker size. These clones have been identified as tolerant varieties through histopathological studies and can be recommended for planting disease prone areas.