Studies on general and specific combining ability variances and their effects in tomato (<em>Solanum lycopersicum</em>

Abstract

The present study was carried out during Rabi seasons of 2016-17 and 2017-18 at Main Experiment Station of Department of Vegetable Science, Narendra Deva University of Agriculture and Technology, Narendra Nagar (Kumarganj), Ayodhya (U.P.) India. The experimental materials of the study comprised of 54 treatments of tomato [40 F1’s and 14 parental lines (10 lines viz., NDT-1, NDT-2, NDT-3, NDT-4, NDT-5, NDT-6, NDT-7, NDT-8, Azad T-6, Arka Saurabh and 4 testers viz., Pusa Ruby, Punjab Chhuhara, Arka Vikash and Arka Meghali]. The 14 parents were involved in a crossing programme to develop a line × tester set (10 lines + 4 testers + 40 F1’s). The experimental materials (40 F1’s and 14 parental lines) were evaluated in Randomized Complete Block Design (RBD) with three replication having each experimental unit with spacing of 60cm × 50cm with plot size of 1.2m ×3.0m.The observations were recorded on fifteen characters, viz., days to 50% flowering, days to first fruit set, days to first fruit harvest, plant height (cm), number of primary branches per plant, number of fruits per cluster, number of fruits per plant, average fruit weight (g), fruit length (cm), fruit girth (cm), number of locules per fruit, pericarp thickness (mm), total soluble solids (TSS), ascorbic acid (mg/100g fresh fruit) and total fruit yield per plant (kg).The analysis of variance for combining ability revealed that there were significant line × tester for all the traits in Y1, Y2 and over pooled, except number of primary branches per plant and pericarp thickness in both year. The parent NDT-2 and NDT-3 had good general combining ability for number of fruits per plant and total fruit yield per plant in both years (Y1, Y2 ) and pooled. Two crosses viz., NDT-5 × Pb. Chhuhara and NDT-6 × Pusa Ruby showed significant and positive sca effects for fruit yield per plant in both the year and pooled. The relative contribution of lines × testers component were higher than the lines and testers for all the characters in both the years, except plant height, number of primary branches per plant, number fruits per plant, ascorbic acid and total fruit yield per plant in both yearsand pooled, testers were higher than the lines for all the characters except plant height. Estimates of sca variance were higher than gca variances for most of the traits except plant height and ascorbic acid in both years and pooled. The value of sca variances were found significant and positive for all the characters except number of primary branches per plant and pericarp thickness in both years, total soluble solids in pooled. Likewise, positive and significant gca variances were also exhibited by almost all the characters except days to 50% flowering, days to first fruit set, fruit length and total soluble solids in both the years and pooled.