INTRODUC TION
Breeding a new crop variety via conventional approach requires selection of complementary parental genotypes with desired traits, followed by crosses and a series of selection and advancement of superior progenies to release candidate cultivars that meet market demands (Shimelis & Laing, 2012). Notable breeding goals in crop cultivar development programmes include higher yield potential and nutritional quality, and enhanced tolerance to biotic and abiotic stresses (Breseghello & Coelho, 2013; Tester & Langridge, 2010). In any crop improvement programme, the following breeding procedures can be distinguished in the order presented: (a) selection of desirable parents with complementary traits to be combined; (b) crosses involving the selected parents and the development of progenies; (c) selection and genetic advancement of the best progenies based on target traits; (d) selection of the best progenies for screening in multiple target production environments to identify the best performing and stable candidate cultivars; and (e) cultivar registration, and seed multiplication and distribution to growers (Shimelis & Laing, 2012).