Morphological description, genetic diversity and population structure of safflower (Carthamus tinctorius L.) mini core collection using SRAP and SSR markers

Abstract

This study was conducted to investigate the genetic diversity and population structure of globally diverse mini core collection of safflower (Carthamus tinctorius L.) using agro-morphological, sequence-related amplified polymorphism (SRAP) and simple-sequence repeats (SSR) molecular markers. Field experiment results showed significant differences between genotypes for agro-morphological traits such as: number of capitula per plant, number of seeds per plant, 1000-seed weight and seed yield. Ten SRAP primer combinations generated 120 polymorphic bands with an average polymorphism information content (PIC) value of 0.23. High allelic variation using 10 SSR markers observed across genotypes, with an average value of 6.8 alleles per locus and relatively high value for PIC (0.69). Pooled molecular data (SSR + SRAP) were used to identify the population structure and genetic diversity using discriminant analysis of principal components (DAPC) and STRUCTURE analysis. The results revealed four clusters within the safflower accessions, while there was no strong correlation between geographical origins and estimated genetic diversity. Our results showed high genetic diversity for both agro-morphological and molecular analysis in the examined safflower germplasm. This mini core germplasm can be used for germplasm management and future safflower breeding programs.