Field Screening of Pepper Germplasm for Sources of Resistance Against Leaf Curl Caused by Thrips (Scirtothrips dorsalis Hood) and Mites (Polyphagotarsonemus latus Banks)

Field screening of pepper germplasm to identify sources of resistance against the leaf curl caused by thrips, Scirtothrips dorsalis Hood and mites, Polyphagotarsonemus latus Banks was undertaken. In the preliminary screening of 308 accessions of chilli germplasm carried out during 1998 -’99, 17 accessions were found to be promising on the basis of visual rating of leaf curl caused primarily by thrips followed by mites. These 17 genotypes were further screened during 1999-’00 and 2000-’01 and scored for leaf curl complex and thrips population. In their reaction to thrips leaf curl, three entries (EC-391082, PBC-613 and NIC-23906) were found resistant, four (EC-305593, EC-378633, EC-391090 and IC-214992) moderately resistant and three (EC-378634, IC-214990 and NIC-23897) tolerant. Against the reaction of the germplasm to mites leaf curl, it was observed that five accessions (EC-378630, EC-378633, EC-391082, IC-214991 and NIC-23897) were found as resistant with less than 1% disease while the incidence ranged from 2.1 to 5.2% in rest of the entries.

Most of the germplasm accessions reacted independently to the leaf curl caused by thrips and mites which is specifically evident with the reaction in lines EC-348630 and IC-214991 which showed nil damage due to mites and heavy leaf curl due to thrips. However, one exotic entry, EC-391082, a paprika type was found to be resistant to the leaf curl caused by bom thrips and mites. Mixed reactions of resistance (resistant to tolerant) to both the leaf curls were observed in the entries, PBC-613, EC-378633, EC-378634, EC-391090, IC-214990, NIC-23897 and NIC-23906.