Morphological characterization and SSR-based genetic diversity of Axonopus compressus mutants

Axonopus compressus mutants require characterization for germplasm identification and parent selection. This study combined morphological evaluation and SSR marker analysis in characterizing phenotypic variation and genetic diversity, aiming to distinguish seven A. compressus variants. The plant materials included the original species (A-0) and six mutant lines (A-1, A-40, A-46, A-91, A-122, A-D). Fifteen morphological traits were measured, showing big phenotypic variation among variants (CV: 1.62% to 59.73%). SSR-based UPGMA clustering separated the variants into three genetic clusters (Jaccard distance: 0.200 to 0.857; PIC: 0.245 to 0.571), providing complementary evidence to the morphological differentiation among variants. Morphological and SSR analyses improved germplasm discrimination and breeding grouping: A-D for compact dwarf growth with strong rooting; A-40, A-122, and A-46 for rapid ground cover and high turf density; and A-1 and A-91 for high biomass production.