Heterosis and Combining Ability in Citrullus mucosospermus (Fursa) for Fruit Traits

Kouakou Fulgence Brou; Sie; Koffi Adjoumani; Yao Didier Martial Saraka; Badie Arnaud Kouago; Cynthia Deborah Adahi

Kouakou Fulgence Brou Laboratoire de Biologie et Am�lioration des Productions V�g�tales, Universit� Nangui Abrogoua, 02 BP 801 Abidjan 02, C�te d'Ivoire.
Raoul Sylv�re Sie Laboratoire de Biologie et Am�lioration des Productions V�g�tales, Universit� Nangui Abrogoua, 02 BP 801 Abidjan 02, C�te d'Ivoire.
Koffi Adjoumani Ecole Normale Sup�rieure d?Abidjan, C�te d'Ivoire.
Yao Didier Martial Saraka Universit� Peleforo Gon Coulibaly (UPGC), UFR Sciences Biologiques, Korhogo, C�te d'Ivoire.
Badie Arnaud Kouago Laboratoire de Biologie et Am�lioration des Productions V�g�tales, Universit� Nangui Abrogoua, 02 BP 801 Abidjan 02, C�te d'Ivoire.
Cynthia Deborah Adahi Laboratoire de Biologie et Am�lioration des Productions V�g�tales, Universit� Nangui Abrogoua, 02 BP 801 Abidjan 02, C�te d'Ivoire.

Keywords: Bebu, Wl�wl� small seeds, heterosis, combining ability

Abstract

The aim of this study was to identify parents and promising hybrid combinations for the improvement of Citrullus mucosospermus (Fursa). 12 F₁ hybrids obtained from a 4x4 full diallel crossing along with their parental lines (Bebu (B), Wllsmall seeds 1 (Wss1), Wllsmall seeds 2 (Wss2) and Wllsmall seeds 3 (Wss3)) were evaluated. The experimental design was a randomized complete block design with three replications. Results showed that hybrids having one parent Bebu, expressed significant positive heterosis effect relative to mid-parental values for characters fruit weight, fruit diameter and fruit volume. Combined analysis of variances for all investigated traits showed significant (P?0.001) mean squares of GCA and SCA for all studied traits, indicating the involvement of both additive and non-additive gene actions in the inheritance of these traits. Non-additive gene effects were predominant for all studied traits. Bebu appeared the best general combiner for FMp, FW, FD and FV while, Wss2 and Wss3 were the best general combiner for NF. Therefore, there were suggested for their incorporation into C. mucosospermus breeding programs, in order to accumulate their favorable genes responsible for increasing fruit yield in promising pure lines. Crosses Wss1em>Wss2 and Wss2em>Wss3 showed significant SCA effects for NF while, crosses B x Wss1, Wss1 x B, B x Wss2, Wss2 x B, B x Wss3 and Wss3 x B presented significant positive values of SCA for FW, FD and FV. Progeny Bss2 had recorded a negative value of SCA for FMp. These promising crosses with significant SCA effects could be included in C. mucosospermus breeding programs, which could be advanced further for the isolation of transgressive segregants in order to develop good inbred lines.