Genome-Wide SSR Markers Reveal Genetic Diversity and Establish a Core Collection for Commercial Hypsizygus marmoreus Germplasm.

Core germplasm, a strategically selected subset of the original germplasm, aims to maximize the representation of genetic diversity within the entire collection. Establishing a germplasm resource bank is essential for the effective management and sustainable utilization of genetic resources. This study developed a core germplasm repository for Hypsizygus marmoreus, a commercially important mushroom species, to capture the genetic diversity of the original collection with a minimal sample size. Genetic diversity and cluster analyses were conducted on 57 representative strains of H. marmoreus, including both cultivated and wild accessions from different regions, using 15 pairs of simple sequence repeat (SSR) markers. DNA molecular identity cards were generated for all germplasms, and cultivation trials with agronomic trait assessments were performed on 24 core accessions. A total of 115 distinct alleles were identified, with genetic similarity coefficients ranging from 0.70 to 1.00. Clustering at a similarity threshold of 0.76 classified the strains into five groups. The core germplasm panel, comprising 24 accessions (42.11% of the total collection), retained full allelic diversity and preserved the genetic and phenotypic variability of the original population, confirming its suitability for parental selection in breeding programs. unique molecular identity codes were developed for each H. marmoreus germplasm by integrating SSR marker profiles with data on geographical origin, fruiting body color, and cultivation traits. These were converted into DNA molecular ID codes, providing a reliable system for rapid identification and traceability of germplasm resources. The findings offer a valuable reference for breeding improvement and the protection of edible fungal varieties with independent intellectual property rights.