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 incre ase genetic diversity among parents and consequently, increase heteroz ygosity, heterosis, and performance of hybrids. In the present study w ith maize (Zea mays L.), the relationship of genetic distance (GD) and specific genetic distance (SGD) among parents estimated from RFLP dat a with ear dry matter yield (EDMY) of their hybrids at grain harvest w as evaluated. The materials comprised six flint (F) and six dent (D) i nbred lines and their 62 diallel crosses (four crosses of closely rela ted lines were excluded). Correlations (r) of GD and SGD with single c ross performance (F1P) and mid-parent heterosis (MPH) and of SGD with specific combining ability (SCA) were significant for all 62 hybrids a nd 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 ge notypic variation for EDMY was not significant in this subset. The pre sent 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, t he results do not support the use of RFLP-based distance measures to p redict the performance of intergroup hybrids, which are of greatest in terest to maize breeders.