Screening of capsicum exotic and indigenous lines for resistance against Pepper mild mottle virus

Abstract

Capsicum is an important offseason vegetable crop among the farmers of Himachal Pradesh (H.P.) and widely grown under protected cultivation. In recent years extensive use of hybrids from many unknown sources under the polyhouse cultivation has escalated the incidence of many viral diseases including seed-borne viruses like Pepper mild mottle virus (PMMoV). The use of genetic resistance is the most feasible strategy for plant virus management. In this study a panel of one hundred and seventy-seven capsicum genotypes including the local landraces, high yielding recommended cultivars and exotic collections were screened for resistance against PMMoV-HP1 isolate. The reaction of the genotypes was recorded and validated using Double antibody sandwich-Enzyme linked immunosorbant assay (DAS-ELISA) and reverse transcriptase-Polymerase chain reaction (RT-PCR). Out of 177 lines, only two accessions PI-159236 and PI-260429 have shown resistance against PMMoV-HP1. All the other accession lines were susceptible to the disease showing mottling, puckering and mild mosaic on the leaves after 10- 14 days of inoculations. The DAS-ELISA assay using PMMoV specific antiserum exhibited strong reaction with an OD value at 405 nm between the range of 0.666- 1.564 which was almost 3-4 times more than the negative control (0.181) in susceptible accessions. In RT-PCR, susceptible accessions yielded an amplification product of ~730 bp, while no amplification was observed in the case of PI-159236 and PI-260429 inoculated with PMMoV-HP1. These two lines can be used in breeding programs to develop PMMoV resistant high yielding cultivar