Chromosomal assignment of microsatellite loci in cotton

Abstract

Microsatellite markers or simple sequence repeats (SSRs) represent a new class of genetic markers for cotton (Gossypium sp.). Sixty-five SSR primer pairs were used to amplify 71 marker loci and genotype 13 monosomic and 27 monotelodisomic cotton cytogenetic stocks. Forty-two SSR loci were assigned to cotton chromosomes or chromosome arms. Thirty SSRs were not located to specific chromosomes in this study. Nineteen marker loci were shown to occur on the A subgenome and 11 on the D subgenome by screening accessions of G. herbaceum (2n = 2x = 26 = 2A1) and G. raimondii (2n = 2x = 26 = 2D5). The aneuploid stocks proved to be very powerful tools for localizing SSR markers to individual cotton chromosomes. Multiplex PCR bins of the SSR primers and semiautomated detection of the amplified products were optimized in this experiment. Thirteen multiples PCR bins were optimized to contain an average of 4 SSR primer pairs per bin. This provides a protocol for high-throughput genotyping of cotton SSRs that improves the efficiency of genetic mapping and marker-assisted programs utilizing SSR markers.