Use of differential levels of mean observed heterozygosity in microsatellite loci of commercial varieties of sugarcane (Saccharum spp).

Abstract

In this study, we measured the genetic diversity within and among a set of 9 commercial sugarcane varieties used for alcohol and sugar production using 17 microsatellite DNA markers. The UGSM148 and UGSM59 primers were monomorphic for all 74 sugarcane samples. The estimated proportion of simple sequence repeated (SSR) polymorphic loci was 88.23%; 17 alleles were detected. The mean gene diversity of all SSR loci was 0.7279. The highest observed heterozygosity (HO) value was found in the RB72454 variety, whereas the lowest HO value was recorded in the SP813250 variety. The SP813250, RB845210, and RB835054 sugarcane varieties were the most genetically uniform varieties. An extremely high level of population differentiation was detected in the varieties exhibiting similar agronomic characteristics. Analysis of the genetic structure of the 9 sugarcane varieties using SSR markers was especially important to identify SSR loci with high levels of heterozygosity and to identify varieties showing the highest levels of heterozygosity. The monomorphic primers may be used to evaluate the genetic stability of sugarcane during cycles of vegetative multiplication, i.e., propagation via rhizomes.