SSR markers associated with fiber yield traits in ramie (Boehmeria nivea L. Gaudich)

Marker-assisted selection (MAS) can effectively promote fiber yield improvement for ramie. However, so far, the lack of molecular markers associated with fiber yield traits impede the application of MAS in ramie breeding. The objectives of this study were to identify simple sequence repeat (SSR) loci associated with fiber yield traits in ramie and to infer population structure and evolutionary genetic relationships. Genetic diversity, population structure, and association mapping analyses were conducted using 107 ramie accessions and 95 pairs of SSR markers. The results indicate that the average number of alleles per locus was 2.64 and that Shannon diversity index values ranged from 0.3797 to 1.4298. The 107 accessions were divided into two subpopulations with extensive genetic variation, indicating that the natural population was representative and could be used for further association analysis of quantitative traits. Association analysis detected a total of 16 stable molecular markers related to yield traits in ramie, including six for plant height, two for ramet number, five for stem diameter, three for skin thickness, and three for fiber percentage. Of these, the SSR marker RAM290 was associated with stem diameter in three environments and can explain 8.32%-23.42% of the phenotypic variation, indicating its potential utility in molecular breeding. These findings will be useful in the genetic improvement of ramie yield traits through marker-assisted selection.