Methods of Constructing Primary Core Collections Based on the Genotypic Values of Malus Sieversii (Ledeb) Roem

摘要

A inlegrative strategy is developed for the establishment of a primary core collection based on predicted genotypic values. A Malus sieversii germplasm collection of 300 accessions with 10 quantitative traits was used to construct core collections. Genotypic values of all quantitative traits of the Malus sieversii collection were unbiasedly predicted based on the mixed linear model approach. The inlegrative strategy is based on stepwise clustering analysis of the predicted genotypic values, selection of accessions from the resulting clusters according to a combination of four hierarchical clustering methods (unweighted pairgroup average method, the single linkage method, the complete linkage method, and Ward's method) and three sampling strategies (random sampling, preferred sampling and deviation sampling), optimisation of the sampling proportion, and validation by means of principal component analysis. A core collection with 60 accessions (at 20% sampling proportion) constructed by the unweighted pair-group average method in combination with the deviation sampling strategy retains the greatest degree of genetic diversities of the initial collection.