Construction of Garlic Core Collections Based on the Agronomic Traits of 366 Germplasm Accessions

In this study, 21 agronomic traits (14 quantitative and 7 qualitative) of 366 garlic germplasm accessions were analyzed using correlation, principal component, and cluster analyses. Genetic diversity was analyzed by the unweighted pair group method with arithmetic mean (UPGMA). Random (R), priority (P), and deviation (D) sampling methods were adopted to construct core collections, and their representativeness was evaluated. The resources exhibited rich genetic diversity and were divided into five categories. Three core collections, R1, P1, and D1, were constructed, and R1 and P1 conformed to core construction principles. A total of 13 R1 traits had higher variances and coefficients of variation, 15 P1 traits showed significant differences in variance and 20 had higher coefficients of variation, and 16 D1 traits exhibited significant differences in mean values compared to those in the original population. Therefore, the three core collections had good heterogeneity, and the P1 group achieved the greatest genetic variation. Based on the three sets, 90 garlic core collections were constructed, accounting for 24.59% of total resources. These core collections provide a scientific basis for the establishment and conservation of a garlic germplasm resource nursery and the breeding of new varieties.