Resistance to anthracnose (Colletotrichum scovillei) in Capsicum annuum: inheritance, QTL identification and progenies selection to develop resistant cultivars

Abstract

Developing sweet and chili peppers resistant cultivars to anthracnose is a challenge for plant breeders inciting the search for resistance sources, inheritance studies, identification of loci, and recombinant inbred resistant lines to fight the disease. In this report, we determined the resistance to anthracnose inheritance in Capsicum annuum L. and identified QTL in unripe fruits. The F1, F2, BC1 and BC2 generations were obtained from the crossing between genotypes UENF 2285 and UENF 1381. The resistance variables evaluated were area under the disease progress curve, incubation period, and latent period in unripe fruits. Disease assessment was performed using a grading scale for a period of seven days after inoculation. For the QTL identification, resistance evaluation was associated with previously mapped molecular markers. At least six genes control the resistance, with one gene with greater effect are responsible for anthracnose resistance. Partial dominance and the additive-dominant model explained the genetic control of the resistance. Six minor QTLs were identified for resistance to anthracnose in the unripe fruit, explaining 23.16% of trait variation. The joint selection of anthracnose resistance and fruit variables resulted in the selection of 60 promising progenies to continue the breeding for sweet pepper resistance to Colletotrichum scovillei.