Identification and genetic diversity analysis of hybrid offspring of azalea based on EST-SSR markers

Azalea is a world famous flower with high economic and ornamental value. The breeding of new azalea varieties is mainly done by cross breeding. However, there is a risk that cross breeding may cause errors in the hybrid offspring due to contamination by exogenous pollen. Therefore, the identification of hybrid offspring is an important part of azalea breeding. In this study, the parents of three hybrid combinations and their 88 F1 hybrid offspring were selected to screen 15 pairs of EST-SSR primers to identify the authenticity of azalea hybrid offspring. The results showed that the authenticity of 88 azalea F1 hybrid progenies could be determined by at least four primer pairs. Genetic diversity analysis of azalea hybrid progeny revealed that the number of alleles and polymorphic information content of the progeny increased to different degrees, and the more distant the genetic distance between parents, the richer the polymorphic information. It is suggested that EST-SSR molecular marker can be applied for the early identification and genetic diversity analysis of the progeny of azalea hybrids. This method is of positive significance for improving the breeding efficiency of new varieties and exploring the genetic background of azalea.