Identification of New Sources of Resistance to Anthracnose Caused by Colletotrichum horii among Persimmon Germplasms

Persimmon (Diospyros kaki) anthracnose, predominantly caused by Colletotrichum horii, is a destructive disease of persimmon. Thus, the evaluation of resistance resources is imperative for persimmon breeding and resistant variety deployment. In this study, the isolate from persimmon branches was identified as C. horii by using molecular and morphological characteristics. A total of 142 varieties were tested for anthracnose disease response by inoculation with the conidial suspension of C. horii. A significant variability was observed among the studied accessions. Only two accessions, which had a hypersensitive reaction with a slight lesion at the infection site at 14 days post inoculation, were highly resistant to anthracnose. A total of 7 and 24 accessions exhibited resistant and susceptible responses, respectively, to anthracnose. A total of 109 varieties with the highest proportion (76.76%) of accessions showed high susceptibility to C. horii. A total of 43 persimmon main cultivars were selected for the re-evaluation of the resistance level by counting the natural disease incidence of branches and fruits that showed similar resistant response. Moreover, nine of highly resistant or resistant accessions possessed desirable agronomic characters, including high fruit weight and strong growth potential. These resistant accessions could be used in the breeding of anthracnose-resistant persimmon varieties.