Field performance of Shrunken-2maize hybrids and its relationship with genetic distance of their inbred parents

Abstract

Maize (Zea mays L.) is an important crop in West and Central Africa, where flint and dent types are the widely cultivated and used as food, feed and raw materials in industries. Sweet maize, the generic term used for maize types with elevated levels of sugar in their kernels, is increasingly popular in Nigeria and other countries of West Africa. This study evaluated the field performance of some super-sweet shrunken-2 (sh-2 ) maize hybrids and determined its relationship with SSR-based genetic distance of their inbred parents. A total of 21 shrunken-2 maize hybrids and seven shrunken-2 maize hybrid checks were evaluated. Analysis of variance was carried out on data collected and correlation analysis between the genetic distance of parental lines and agronomic traits of their hybrids. There were significant differences (P < 0.01) among the hybrids for all agronomic traits studied. Field emergence ranged from 28.2 to 97.4%; while fresh cob weight and husk cover (1-9) ranged from 0.05 to 0.17 and 2.7 to 6.7 g plant-1, respectively. Among the hybrids, UI1 x UI75 was the most promising, combining high emergence with high fresh cob yield, good husk cover, resistance to endemic foliar diseases, good plant aspect and moderate ear aspect. Genetic distance between parental inbred lines was not useful for predicting hybrid performance among the sets of shrunken-2 inbred lines considered. The parental lines, however, have potential for use in shrunken-2 maize breeding programmes.