Two genes control aluminum tolerance in maize: Genetic and molecular mapping analyses

Abstract

We have identified two loci linked to aluminum (Al) tolerance in the maize inbred line Cat-100-6 by means of restriction fragment length polymorphism (RFLP) and bulked segregant analysis (BSA). A segregating population F2was obtained from a cross between Cat-100-6 (Al tolerant) × S1587-17 (Al sensitive) parents. Subsequently two DNA bulks of individuals, displaying a contrasting Al tolerance trait were generated from F2. From a total of 158 markers used, 30 markers were identified showing polymorphism between parents and bulks. The segregation results derived from the hybridization from these 30 markers and 56 individuals from F2revealed 10 markers cosegregating with the Al tolerance which were located in two linkage groups. The linkage groups were composed of 6 and 4 markers, and they were mapped on the short arm of chromosomes 6 and 10, respectively. From these observations, we deduce that two loci are involved in this trait in Cat-100-6 line. QGENE software was used to study the correlation between these two loci and the trait for aluminum tolerance. The results indicate that the locus on chromosome 10 has the stronger effect, and it is responsible for the major part of the variability of the trait.Key words: maize, aluminum tolerance, molecular mapping, somaclonal variation.