RELATIONSHIP OF RESTRICTION-FRAGMENT-LENGTH-POLYMORPHISMS AMONG EUROPEAN MAIZE INBREDS WITH EAR DRY-MATTER YIELD OF THEIR HYBRIDS

Restriction fragment length polymorphisms (RFLPs) may be used to increase genetic diversity among parents and consequently, increase heterozygosity, heterosis, and performance of hybrids. In the present study with maize (Zea mays L.), the relationship of genetic distance (GD) and specific genetic distance (SGD) among parents estimated from RFLP data with ear dry matter yield (EDMY) of their hybrids at grain harvest was evaluated. The materials comprised six flint (F) and six dent (D) inbred lines and their 62 diallel crosses (four crosses of closely related lines were excluded). Correlations (r) of GD and SGD with single cross performance (F1P) and mid-parent heterosis (MPH) and of SGD with specific combining ability (SCA) were significant for all 62 hybrids and the Subset of 14 F x F hybrids, but not for the subset of 36 F x D hybrids. The r's for the 12 D x D crosses were inconclusive because genotypic variation for EDMY was not significant in this subset. The present study indicates that RFLP-based genetic diversity may be employed to select parents for high MPH and F1P in a breeding program, wherein intragroup and intergroup hybrids are considered together. However, the results do not support the use of RFLP-based distance measures to predict the performance of intergroup hybrids, which are of greatest interest to maize breeders.