Heterotic relationship between INERA, CIMMYT and IITA maize inbred lines under drought and well-watered conditions

The Institute of Environment and Agricultural Research of Burkina Faso has extracted a large number of inbred lines from Open Pollinated Varieties, which are environmentally adapted and adopted by farmers. However, there is a gap in knowledge on heterotic grouping of these lines and their heterotic relationship with exotic lines. Twenty-four CIMMYT and INERA white lines were crossed to two CIMMYT testers and; twenty six IITA and INERA yellow inbred lines were crossed to two IITA testers. Two trials composed of 48 white testcrosses and 52 yellow test¬crosses plus three checks were evaluated in well-watered and drought stress conditions in the dry season over two years. Significant general combining ability (GCA) effects due to lines and, testers for many traits including grain yield were observed. However, specific combining ability (SCA) effects for most traits except for plant and ear heights were not significant. Of the 24 CIMMYT and INERA white lines, 15 lines could be classified into het¬erotic groups based on the SCA effects and testcross mean grain yield in well-watered environment and, 10 lines were classified under drought stress condition. Eighty five percent of the IITA and INERA yellow lines were clas¬sified into heterotic groups in both drought and non-drought conditions. Thirteen yellow lines and five white lines maintained their heterotic groups in both well-watered and water-stressed conditions