Genetic analysis and QTLs identification for resistance to the Begomovirus causing pepper leaf curl virus (PepLCV) disease

Pepper leaf curl virus (PepLCV) disease spread by Begomovirus and infected by whiteflies, is the most destructive disease of pepper worldwide. The genetic basis of resistance to PepLCV was studied in F-1 and F-2 generations developed from Punjab Lal (P-1) x Kashi Anmol (P-2) and back cross population (B-1 and B-2) for segregation analysis following a mixed inheritance model. Analysis of the segregation data revealed that PepLCV resistance in Punjab Lal is controlled by pooled additive genes and additive x additive polygenes. Whereas, the F-2 Mendelian population was segregated into 1:3 genetic ratio and showed monogenic recessive gene action. A total of 132 F-2:3 families were evaluated for PepLCV resistance in two separate trials identified eight QTLs on five linkage groups (LG1, LG3, LG5, LG7 and LG8). Out of eight QTLs, six were stable in both the trials except QPlcv.teri.1.1 and QPlcv.teri.8.4. The six QTLs identified in both seasons together explained 69.36% (F3/1st trial) and 58.69% ( F3/2nd trial) of the total phenotypic variation. Three major QTLs were observed on LG8 QPlcv. teri.8.1, QPlcv.teri.8.2 and QPlcv.teri.8.3 explained 7.82, 34.23 and 14.27 in F-3/ 1st trial whereas 5.86, 28.99 and 12.02 in F-3/2nd trial, respectively.