Abstract
For the breeding of varieties resistant to tea gray blight caused by Pestalotiopsis longiseta (Spegazzini) Dai et Kobayashi, varietal differences of resistance to the fungus were investigated in 195 cultivars and genetic resources of tea. The resistance to the disease was classified into 5 grades from high resistance to hight susceptibility based on the rate of formation and the size of zonate spot lesions.
In resistance to tea gray blight, most of the Japanese local varieties were resistant, but some cultivated varieties and breeding lives such as 'Sayamamidori, Yabukita, Toyoka, Hokumei, Asatsuyu, Natsumidori, Okumusashi' and 'Saemidori' for green tea were susceptible or slightly susceptible.
The Japanese local varieties were almost susceptible, China type plants were the middle susceptible and Assam hybrids were slightly susceptible.
