MSc

The project entitled “Development of hybrids in yard long bean (Vigna unguiculata subsp. sesquipedalis (L.) Verdcourt)” was carried out at the Department of Olericulture, College of Agriculture, Vellayani, during 2015-2016 to study the heterosis and combining ability of yard long bean and to develop superior hybrids with high yield and quality.
The experiment was carried out in two parts. In part I, eight diverse parents viz., VS 34-culture VS 6 (P1), VS 50 (P2), VS 16 (P3), VS 54 (P4), VS 13 (P5), VS 26-Vellayani Jyothika (P6), VS 38 (P7) and VS 29 (P8) were raised in a crossing block. They were crossed in half diallel fashion and 28 F1 hybrids were produced. In part II, hybrids were evaluated along with their parents and check in a randomized block design with 37 treatments and three replications.
Analysis of variance revealed significant difference among the treatments for all traits except seeds pod-1 for parents. Among parents, VS 29 recorded the highest yield (848.74 g plant-1) and pods plant-1 (56.67). The highest pod weight (27 g) and pod length (66.28 cm) was recorded in VS 50. Pod protein was maximum in VS 16 (6.44 %) while VS 38 had the best keeping quality. Among the hybrids, highest yield was recorded in VS 34 x VS 50 (1414.55 g plant-1). VS 34 x VS 13 recorded maximum number of pods plant-1 (107.17) and pod protein (7.01 %). Highest pod weight was recorded in VS 50 x VS 16 (30.67 g) whereas VS 54 x VS 26 had the maximum pod length (71.27 cm). VS 13 x VS 38 had the best keeping quality. Mild incidence of pod borer, mosaic and fusarium wilt was noticed.
The estimates of general combining ability (gca) effects revealed that VS 50 was the best general combiner for days to first flowering, peduncle length, pod weight, seeds pod-1, yield plant-1 and days to harvest. VS 13 was the best general combiner for quality characters. The estimates of specific combining ability effects revealed that VS 34 x VS 50, VS 34 x VS 13, VS 50 x VS 26, VS 54 x VS 26 and VS 16 x VS 38 were the most promising crosses for yield, pods plant-1 and pod protein. The σ2gca and σ2sca ratio indicated preponderance of non-additive gene action for all traits except pod weight.
Relative heterosis, heterobeltiosis and standard heterosis over variety (Vellayani Jyothika) and hybrid (NS 634) were worked out for all yield and quality characters. The highest standard heterosis over Vellayani Jyothika and NS 634 for yield plant-1 was recorded in VS 34 x VS 50 (129.05 % ; 197.46 %) followed by VS 50 x VS 26 (119.90 % ; 185.58 %) and VS 34 x VS 13 (103.31 % ; 164.03 %). The highest standard heterosis for pod length, pod weight and pods plant-1 was recorded in VS 54 x VS 26 (35.66 % ; 34.34 %), VS 50 x VS 16 (52.82 % ; 28.46 %) and VS 34 x VS 13 (210.39 % ; 295.30 %) respectively. For pod protein, highest standard heterosis was observed in VS 34 x VS 13 (61.40 % ; 28.08 %) while for keeping quality VS 13 x VS 38 (-37.93 % ; -37.15 %) had the maximum standard heterosis.
Based on the mean performance, specific combining ability and standard heterosis, the hybrids VS 34 x VS 50 (Githika x Kakkamoola Local), VS 50 x VS 26 (Kakkamoola Local x Vellayani Jyothika) and VS 34 x VS 13 (Githika x Neyyattinkara Local) were the most promising for yield and quality characters. Among these hybrids VS 34 x VS 50 and VS 50 x VS 26 were tolerant to CABMV whereas, VS 34 x VS 13 was resistant.