Screening of Parents and Hybrids Resistant to Late Blight and Leaf Curl Virus Diseases in Tomato

The experimental material included 21 F1 hybrids (developed by half diallel fashion), 7 parents and standard check were all planted in randomized complete block design with three replications at Bihar Agriculture University, Sabour. Among the parents Pusa Rohini, Arka Vikash and S. pimpinellifolium whereas, among the crosses, Pusa Rohini × Arka Vikash, H-86 × Arka Vikash and Arka Vikash × S. pimpinellifolium were showed highly resistant for per cent disease incidence and coefficient of infection of late blight and ToLCV. Maximum heterosis over better parent and standard parent in desirable direction were found in Pusa Rohini × Arka Vikash (-48.61, -52.84), (-72.12, -76.42) and Arka Vikash × Arka Abha (-42.02, -50.35), (-61.35, -75.17) for per cent disease incidence and coefficient of infection of late blight. Whereas heterosis for PDI and CI of ToLCV was found in cross combinations namely, Pusa Rohini × S. pimpinellifolium (-46.35, -65.08), (-77.50, -88.35) and Arka Vikash × S. pimpinellifolium (-60.85, -64.32) (-86.95, -88.27) over better parent and standard parent. The cross identified as best specific combiners Arka Vikash × S. pimpinellifolium for per cent disease incidence and coefficient of infection of late blight and ToLCV. Among the parents for late blight the per cent disease incidence and coefficient of infection were significantly shown by Arka Vikash and Arka Abha. Against ToLCV (PDI and CI) resistance, parents Pusa Rohini, S. pimpinellifolium and Arka Vikash were exhibited significantly negative GCA effect.