Evaluation of the possibility of utilization sub-tropical maize germplasm in temperate regions of Iran

Two groups of sub-tropical maize germplasm including 14 early maturing hybrids and 23 intermediate-late maturing varieties with 2 adapted commercial hybrids, KSC 647 (intermediate maturity) and KSC 704 (late maturity), were evaluated in two separate experiments using randomized complete block design with 3 replications, at 4 locations in Iran (Karaj-Gorgan-Darab and Dezful), during 2002 cropping season. The results indicated that these type of germplasm performed better adaptability in Darab(28º and 46', latitude) and Dezful (32º and 24', latitude) due mainly to the similarity of the latitude to the Origin of the germplasm. The hybrids derived from crosses between varieties had competitive performance as compared to local check hybrids derived from crosses between inbred lines. Although these hybrids were early maturity at the origin, they were of late maturing behavior at the experimental sites as did local hybrids. High genetic variation, due mainly to differences between their parental varieties and different origin, as compare to temperate germplasm, these germplasm are valuable sources for temperate maize breeding programs in Iran. This is more important considering the results of the second experiment which consisted of open-pollinated varieties from only one heterotic group, and demonstrated broader genetic base. These germplasms are to be used to increase the efficiency of maize hybrid breeding programs in Iran.