Evaluation of combining ability and heterosis of six bitter gourd (Momordica charantia L.) self-pollinated lines at S5 generation

Research and production of hybrid seed for bitter gourd are still limited in Vietnam. It is difficult for creating inbred lines and determining combining ability and heterosis crosses because hybrid seed production is highly timeconsuming. The objective of this study was to determine bitter gourd inbred lines with high combining ability and heterosis. The single factor experiment was laid out in a randomized complete block design (RCBD). There were 22 treatments including six bitter gourd inbred lines at S5 generation, 15 single crosses and Vino Galatico - S2 variety (control) with three replications each. The results indicated that seven crosses named D9 x D8, A2 x D8, A3 x D8, A2 x D9, A4 x A2, A1 x A2 and A1 x A4 were similar to or higher than the control in the analysed parameters such as fruit size, fruit weight and harvested yield. The D9 and D8 lines were identified in hybrid superiority used for male or female parent with high heterosis. The A1 and A2 lines were found appropriate in male and female parents, respectively. The A1 x A2 cross showed good value of specific combining ability for total fruits per plant and harvested yield. Moreover, the values of heterosis for fruit length, total fruits and harvested yield were higher than 10 percent.