Abstract

Controlled crosses were carried out to determine crossability among five selected cassava varieties in terms of seed set per cross and influence of maternal inheritance on seed set in cassava. The experiment was carried out at the Teaching and Research Farm of the Department of Agronomy, University of Ibadan Oyo State, Nigeria. Three yellow root varieties (IITA-TMS-I011412, IITA-TMS-I011368 and IITA-TMS-I070539) selected for their high β-carotene content and two white root varieties (IITA-TMS-I30752 and COB-7-25) selected for their high dry matter content and acceptable plant architecture among subsistence farmers were crossed in a reciprocal diallel design with no selfing. Fourteen hybrid populations were developed and data obtained were analyzed using T-Test and simple linear correlation. The result showed that genotype and maternal inheritance influenced seed setting in cassava. The cross IITA-TMS-I011368 x IITA-TMS-I011412 gave the highest seed set percentage (57.1) and the two parents were the best female and male parents, respectively. This was followed by IITA-TMS-I30752 x IITA-TMS-I011412 (39.8%), IITA-TMS-I011368 x IITA-TMS-I070539 (26.5%), IITA-TMS-I070539 x IITA-TMS-I011412 (24.9%) and IITA-TMS-I30752 x IITA-TMS-I011368 (24.1%). Reciprocal differences were observed for crosses between IITA-TMS-I30752 and IITA-TMS-I011412; IITA-TMS-I011412 and IITA-TMS-I011368; IITA-TMS-I011412 and COB-7-25 which suggests that seed setting in cassava is influenced by cytoplasmic genes which are transmitted exclusively by the maternal parent. The best female and male parents (IITA-TMS-I011368 and IITA-TMS-I011412) in terms of percentage seed set in this study are good candidates as parents to generate large populationsin breeding for high carotene content in cassava.

Keywords: β-carotene content; Hybridization; Maternal inheritance; Percentage seed set; Plant architecture