# Intraspecific Genetic Diversity Analyses of Yam (Dioscorea polystachya Turcz.) Based on DUS Traits and SSR Molecular Markers

## TL;DR

This study uses genetic markers and plant traits to analyze diversity in yam varieties, helping improve breeding and conservation efforts.

## Contribution

The study introduces a refined set of 14 core DUS traits and 19 SSR markers for efficient yam variety identification.

## Key findings

- 19 SSR markers and 50 DUS traits effectively distinguished 113 yam accessions.
- A refined set of 14 core DUS traits improved variety identification efficiency.
- The study identified potential synonyms and homonyms among yam accessions.

## Abstract

Yam (
Dioscorea polystachya
Turcz.) is an asexually reproduced food and traditional Chinese medicinal crop with extensive genomic variability. However, the detailed characterization of genetic diversity among different yam germplasm samples is still insufficient. This study evaluated the genetic divergence and genetic structure of 113
D. polystachya
accessions collected from 17 provinces in China based on 50 distinctness, uniformity, and stability (DUS) traits and 19 simple sequence repeat (SSR) markers. All the selected varieties were categorized into three groups based on morphological characteristics and further validated by principal component analysis. Furthermore, 14 core traits, including 6 leaf traits, 4 tuber traits, 3 bulbil traits, and 1 stem trait, were selected to increase field inspection efficiency. SSR fingerprinting, utilizing 19 highly polymorphic markers, successfully distinguished all 113 yam varieties, revealing relatively high levels of genetic variation. Interestingly, the optimal genetic structure defined three groups, whereas a finer‐scale model consistently classified the varieties into five groups, corroborating the genotypic cluster analysis. Furthermore, this study preliminarily identified 10 groups of potential heterotypic synonyms and 13 groups of potential homonyms among the yam accessions. These results demonstrate that the 19 selected SSR markers, in conjunction with DUS traits, can effectively discriminate the 113
D. polystachya
varieties. Our findings provide critical insights for the conservation of pure breeds and the utilization of Dioscorea germplasm resources.

The 113
D. polystachya
accessions exhibited substantial genetic diversity, clearly distinguished using 19 SSR markers and 50 DUS traits. A refined set of 14 core DUS traits was established, significantly improving variety identification efficiency. These selected markers and traits provide valuable tools for genetic research and support the utilization of germplasm in future breeding programs.