Genetic Variability in Seed Dormancy, Germination and Germination Enhancement of Some Cassava (Manihot esculenta Crantz) Genotypes

摘要

The sustainability of cassava production for food security and agro-industrial demands amidst the growing population and changing global environmental conditions is an interest for breeding programs. The response of cassava seeds to dormancy and germination is a prerequisite for the choice of parents for eventual hybridization. A screen-house experiment was carried out to investigate variations in the dormancy and germination of cassava seeds at the International Institute of Tropical Agriculture (UTA) Ibadan. The study involved a preliminary germination test of seeds of 30 cassava genotypes. Four genotypes (TMe359 'TMel700', 'TMel747' and 'TMel945') were selected for a test of probable differential responses to two temperature regimes of (45 and 55°C) at three continuous intervals of 5, 10 and 15 days. There were significant differences in the genotypes (P < 0.05) in days to germination and percentage of germination. Significant differences (P < 0.05) also existed among the genotypes at different temperatures for days after planting. Each of the four genotypes demonstrated unique quadratic trend response to imbibition in hot water. Wet heat treatment appropriately aided imbibition in the four genotypes studied. Genotypic variation in germination as observed in this study could be a guide for cassava breeders for selection of genotypes with low dormancy as a maternal parent for crosses.