Genetic diversity of Thailand reserved mulberry germplasm based on morphological characteristics and newly developed EST-SSR and SRAP markers

Abstract

Mulberry (Morus L.) is an important crop for the sericulture industry, serving as the primary food source for the silkworm Bombyx mori L. Thailand has a long history of practicing sericulture and has imported and improved upon many indigenous cultivars to create new hybrid offspring. It is crucial to understand the genetic divergence of these accessions for their conservation and utilization in selection and breeding. In this study, 85 representative mulberry accessions in Thailand were observed morphology and analyzed for their genetic relationships using SRAP and EST-SSR markers. The findings indicate that the morphological traits of Thai mulberry are distinctive enough to differentiate between M. macroura Miq. and wild hybrid mulberry, and a group consisting of M. alba L. and M. australis Poir., and their hybrids. 12 SRAP primer combinations produced 193 polymorphic amplicons with an average of 17.0 bands per primer set, and the mean of PIC was 0.259. Eleven novel EST-SSR primers generated 35 amplicons with an average of 3.2 alleles per primer set, and the average PIC was 0.139. The dendrogram obtained using the UPGMA algorithm in R studio showed that the wild and wild hybrid mulberry were genetically distant from the domesticated species studied here. These findings have important implications for the characterization, improvement, molecular systematics, and conservation of Thai mulberry germplasm.