Analysis of Quantitative Trait Loci of some agronomic traits in maize

ABSTRACT: In order to identify microsatellite markers linked to number of tassel branches, days to pollinating, days to silking, ear height and plant height, the F2:3 population with cross K1264/1 and K47/2-2-1-3-3-1-1-1 genotypes, were assessed. Polymorphism of the parents was assessed by 60 microsatellite primers and polymorphic primers were used for assessing 135 F2 genotypes. The primers were categorized in four affinity groups and covered 558.8 cM of maize genome. Quantitative trait locus (QTL) analysis based on composite interval mapping for the studied traits identified 26 QTL. Five QTL were identified for tassel branches which explained 14.73% of the phenotypic variations. Five QTL were identified for the number of days to pollination, and the second QTL found in this trait (with a 2.01 cM from the phi213984 marker) was similarly seen in the number of tassel branches. For days to silking one QTL was identified which explained 16.02% of the phenotypic changes. Three QTL were identified for ear height and 12 QTL for plant height which explained 51.21% and 89.99% of the phenotypic variations, respectively. The fourth QTL in the ear height (51.15%), the ninth QTL (36.34%) and tenth (32.61%) in the plant height were QTLs with major effects since they explained higher percentages of phenotypic variations, and can be presented as a gene for these traits. The identified QTLs in this study can be used for determining the important gene locations of these traits. Moreover, the microsatellite primers that have a linkage with these traits can be used in breeding programs through selection by markers.