Analyse génétique des composantes du rendement du maïs en zone sèche au Burkina Faso

Résumé

Erratic rainfall is a major maize production constraint in dry areas of Burkina Faso. The development of drought-tolerant maize germplasm is a major goal of our breeding programme, mainly based on 100-kernel weight P100. The present study involved genetic analysis and heritability of yield and yield components. Using two inbred maize lines (Ku 1414, TZi 25) with different drought tolerances, we crossed, selfed, and backcrossed them with their respective parents to develop F1, F2, BCR, and BCS forms, respectively. A randomized complete block design was used at Kamboinse Station. Data for yield (yld), ear diameter (ED), ear length (EL), kernel row number (KRN), kernel per row (K/R), 100-kernel weight (P100) were recorded in 1994 and 1995 (Table 1). Analysis of separate genetic factors highlighted dominant effects (Table 2). Heritability (hns) was high for P100 (0.94) and ED (0.60), and low (hns < 0.50%) for EL (0.13), KRN (0.46), and K/R (0.41). The success of breeding procedures depends on the extent of genetic effects. The use of some highly heritable parameters (P100, ED) could reveal the best parents, thus making it possible to quickly improve crop yields. We conclude that recurrent selection is an efficient genetic improvement strategy for developing maize populations adapted to dry areas of Burkina Faso.