|Riassunto in Inglese:|
Colletotrichum acutatum is considered the major causal agent of pepper and chili anthracnose in many regions of the world and can lead to significant economic losses. To date, no commercial resistant varieties are available. Resistance to C. acutatum could be introgressed in C. annuum by interspecific hybridization with highly resistant wild accessions belonging to C. baccatum and C. chinense. Eleven Capsicum accessions and the commercial variety “Quadrato d’Asti” were screened for resistance to anthracnose by inoculating detached fruits with a virulent C. acutatum isolate (CRA-PAV ER1856) by a microinjection inoculation method. The inoculated fruits were incubated at room temperature (25°C) under 24 h photoperiod for 7 days for the development of anthracnose lesions. After 7 days, genotypes with diameter lesion < 4 mm2 or localized cell death surrounding injection were rated as resistant, and moderately resistant if the diameter of lesion was within 4-8 mm2. Two genotypes (CAPCHI10 and CAPEXI04) were resistant, three (CAPCHI03, CAPCHI05 and CAPFRU06) resulted moderately resistant, while variety “Quadrato d’Asti” and three genotypes (CAPBACB03, CAPBACP04 and CAPCHI02) were susceptible. The other accessions (CAPBACP03, CAPFRU08 and CAPFRU07) showed moderately susceptibility. The availability of source of resistance to Colletotrichum fruit rot is promising for successful breeding strategies to the disease. Additional tests will be carried out to validate these preliminary results and to increase the number of tested accessions. Molecular characterization by the CAPS marker CaR12.2M1, associated to the CaR12.2 resistance locus, will be performed on the evaluated accessions.