关键词: 草莓, 种质资源, 果生炭疽菌, 炭疽病, 抗性

Abstract:

【Objective】 The objective of this study is to evaluate the anthracnose resistance level of 71 strawberry accessions including 24 accessions from 12 Fragaria species, 41 cultivars from Fragaria × ananassa and 6 interspecific hybrids, and to provide a basis for the utilization of strawberry germplasm resources in resistance breeding.【Method】 Colletotrichum fructicola isolate Gwha-1, which was isolated from strawberry petiole, was used as inoculation pathogen. The suspension of C. fructicola (1×10 ⁶ conidia/mL) was evenly inoculated on the leaf surface and petiole of strawberry leaves by in vitro inoculation method. Inoculated leaves were moisturized at 28℃ for 4 days, and then the incidence of each leaf was investigated. The lesion number on leaf surface, the largest lesion diameter on leaf surface, and the maximum lesion length on petiole were counted. Correlation analysis was performed on the lesion length on petiole, the lesion number and the lesion diameter on leaf surface of different materials using IBM SPSS 15.0 software. The disease severity of each leaf was ranked according to the lesion length on petiole. The disease index of each material was calculated, and the anthracnose resistance of the tested materials was evaluated based on the disease index of petiole after inoculation with C. fructicola isolate Gwha-1. The general linear model procedure (PROC GLM) in SAS was used to analyze the differential significance (P＜0.05) among five strawberry species, including F. × ananassa (41 accessions), F. mandschurica (3 accessions), F. viridis (4 accessions), F. nilgerrensis (3 accessions), and interspecific hybrids (6 accessions). Species were used as fixed factors and tested materials as random factors.【Result】 There was no completely immune material to anthracnose caused by C. fructicola in the tested materials, and all materials had different degrees of disease incidence after 4 days of inoculation with C. fructicola isolate Gwha-1. The comparison of different materials showed that the lesion length on leaf petiole was positively correlated with the lesion number on leaf and the lesion diameter on leaf surface after inoculation. According to the lesion length on petiole after inoculation with C. fructicola, the anthracnose resistance of the tested materials could be distinguished. The numbers of materials with anthracnose resistance level of high resistance, resistance, medium resistance, medium susceptibility, susceptibility and high susceptibility were 17, 20, 21, 3, 6 and 4, respectively, 81.7% of the tested materials had medium resistance, resistance or higher resistance level to anthracnose caused by C. fructicola. ‘3 Gongzhu’ ‘Senga Sengana’ ‘Darselect’ ‘Allstars’ ‘Kaorino’ ‘Veestar’ and ‘Jingzangxiang’ in the F. × ananassa, and ‘Tokun’ in interspecific hybrids had high resistance to anthracnose. In the wild species of strawberry, the resistance level of all the F. mandschurica, F. viridis and F. orientalis tested materials was high resistance, and the disease index of F. mandschurica and F. viridis was significantly lower than that of F. × ananassa. 【Conclusion】 The anthracnose resistance of 71 strawberry resources was evaluated. Seven cultivars of high resistance to anthracnose were selected from the cultivated strawberries, including ‘3 Gongzhu’ ‘Senga Sengana’ ‘Darselect’ ‘Allstar’ ‘Kaorino’ ‘Veestar’ and ‘Jingzangxiang’. There are high anthracnose resistant resources in F. mandschurica and F. viridis. Their resistance level to anthracnose is significantly higher than that of F. × ananassa, which can be used as an antigen source of anthracnose in interspecific hybridization.

Key words: strawberry, germplasm resources, Colletotrichum fructicola, anthracnose, resistance