Correlation between the DNJ content and genetic diversity of SSR markers of 36 mulberry (Morus spp.) germplasm resources

Abstract

1-deoxynojirimycin (DNJ) has certain medicinal value in lowering blood sugar, lowering blood fat, antiviral and anti-tumor, and Mulberry is one of known species with the highest DNJ content. To take full advantage of medicinal benefits of mulberry, the internal relationships of the genetic diversity of SSR markers and DNJ content was assessed in this study, so as to provide the basis for the exploitation and breeding of mulberry resources with high DNJ content. The results showed that the DNJ content in the leaves of the 36 mulberry germplasm resources varied significantly, with the mean value of 1.2794 mg/g, the amplitude of 1.03–1.61 g/g, and the coefficient of variation of 0.1276. Polymorphism was found in by 5 pairs of SSR primers from 36 mulberry germplasm resources, and a total of 32 genotypes were deteced. The mean allele number was 3.8, the mean heterozygosity was 0.62, the polymorphic information content of 0.61. Cluster analysis based on the genetic distance of SSR markers showed that the tested 36 mulberry germplasm resources could be divided into 3 class, and the analysis based on DNJ content showed that they could be divided into 2 clades. Comparison of the two cluster analyses displayed that the DNJ content in mulberry germplasm resources of the same group was similar. The above results revealed that the genetic diversity of SSR markers was similar to the genetic diversity of DNJ content in mulberry leaf.