Resistances to anthracnose (Colletotrichum acutatum) of Capsicum mature green and ripe fruit are controlled by a major dominant cluster of QTLs on chromosome P5

Anthracnose (Colletotrichum spp.) is a serious disease worldwide in pepper (Capsicum) production. Inheritance of resistance to Colletotrichum acutatum from a Capsicum chinense accession (PBC932) was studied in a BC1 population derived from a hybrid with Capsicum annuum line 77013 (susceptible) using a QTL analysis method. Resistance test was performed on detached mature green and mature red fruit under laboratory conditions by evaluated in disease incidence, true lesion diameter and overall lesion diameter. Based on a linkage map with 14 linkage groups, 385 markers (SSR, InDel and CAPS), 1310.2 cM in length, inclusive Composite Interval Mapping (ICIM) revealed main effect QTLs located in a close marker interval on P5 chromosome for all fruit stages and resistance criteria, and four minor-effect QTLs only at green mature stage. Identification of recombinant individuals suggested that resistance in green versus red fruit may be controlled by distinct genes within the QTL interval on P5.