Genetic diversity analysis of volunteer wheat based on SSR markers

Volunteer wheat is a kind of wheat with weed characteristics, distributed widely in the main wheat-producing areas of China. It seriously damages the yield and quality of cultivated wheat. To study the genetic diversity and population structure within and between volunteer wheat and cultivated wheat (Triticum aestivum L.), 195 volunteer wheat seeds and 29 cultivated wheat seeds were analysed based on 16 pairs of highly-polymorphic microsatellite simple sequence repeats (SSR) primers and a microchip capillary electrophoresis (MCE) detection system. A total of 110 polymorphic alleles were detected by MCE with each pair of primers identifying 2-15 alleles with an average of 6.875 alleles. The polymorphic information content (PIC) ranged from 0.1089 to 0.7843, with an average of 0.5613. Genetic diversity arguments from 224 samples showed that the volunteer wheat was more varied than cultivated wheat. Based on the SSR information, the 224 samples were classified into seven groups, which corresponded to the volunteer wheats and cultivated wheats through principal coordinates analysis (PCA). We propose that the volunteer wheat and cultivated wheat have rather distant phylogenetic relationships. Hence, it is important for wheat breeding to study the genetic relationship between volunteer wheat and cultivated wheat.