Fruit Setting in Cassava (Manihot esculenta Crantz) Varieties as Influenced by Genotype and Maternal Inheritance

Hand pollination was carried out among five varieties of cassava in reciprocals to investigate the influence of genotype and maternal inheritance on fruit setting in cassava varieties. The experiment was conducted at the Teaching and Research Farm of the Department of Agronomy University of Ibadan, Nigeria. Three yellow flesh varieties (IITA-TMS-I011412, IITA-TMS-I011368 and IITA-TMS-I070539) with high β-carotene content and two white flesh varieties (IITA-TMS-I30752 and COB-7-25) with high dry matter content were crossed in a reciprocal, with no selfing to produce fourteen hybrid seeds. Data obtained were subjected to correlation analysis and two-tailed t-test. The result showed that both genotype and maternal inheritance influenced fruit setting in cassava species. The cross IITA-TMS-I011368 x IITA-TMS-I011412 gave the highest fruit set percentage (57.1) and 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). Significant reciprocal difference (p = 0.02) was recorded between the F1 and the reciprocal crosses, which implies that fruit setting in cassava is significantly influenced by cytoplasmic genes which are exclusively transmitted by the maternal parent. IITA-TMS-I011368 and IITA-TMS-I011412 were the best female and male parent across the five genotypes, with mean fruit set percentage of 24.9 and 28.8, respectively. In this regard, the best female and male parents (IITA-TMS-I011368 and IITA-TMS-I011412) are good candidates for generation of large populations of β-caroten-rich cassava varieties.