[Development of DNA molecular identity cards for germplasm of Murraya paniculata based on SSR markers]

To promote the conservation and utilization of the germplasm resources and provide a basis for the breeding of new varieties of Murraya paniculata, this study analyzed the genetic diversity of the germplasm resources and developed the molecular identity(ID) card of M. paniculata. Multiple fluorescence PCR-capillary electrophoresis was performed for 65 germplasm accessions of M. paniculata based on 9 SSR markers identified from the M. paniculata genome, and the molecular weights and alleles of the amplified bands were analyzed. According to the banding patterns of the 9 SSR primers, this study analyzed the genetic diversity of each germplasm accession of M. paniculata and developed molecular ID cards for the test samples. The results showed that 9 pairs of SSR primers detected 78 alleles, with an average of 8.67 alleles. The observed and expected heterozygosity was 0.338-0.831(average of 0.601) and 0.413-0.853(average of 0.721), respectively. The Shannon's information index varied within the range of 0.880-1.994, with an average of 1.41. The polymorphic information content was within the range of 0.391-0.835, with an average of 0.696, which indicated rich genetic diversity. When the genetic identity was 0.347, the 65 germplasm accessions were classified into 5 groups. Based on the results, this study employed the 5 SSR primers with higher polymorphisms to develop the molecular ID cards for the germplasm resources of M. paniculata and created QR code ID cards for the 49 core germplasm accessions preserved in the Yunfu germplasm nursery, laying a foundation for the new variety breeding, production, utilization, and traceability of M. paniculata.