Sampling strategy to develop a primary core collection of apple cultivars based on fruit traits

Abstract

A total of 435 accessions of apple germplasm collected from the Xincheng National Apple Germplasm Repository and 10 morphological traits of them were used for studying the optimal sampling strategy for primary core collection of apple (Malus domestica Brokh). In order to acquire the appropriate primary core collection,.. different entire sampling ratio and sampling scheme were compared in the study. Six entire sampling ratios were tested and the sampling schemes following stratification into two
levels, including the grouping principle, sampling proportion within group were studied. The results showed that 10% should be the suitable entire sampling ratio for primary core collection of apple. Under 15% entire sampling ratio, the optimal sampling scheme was grouped based on cultivar group combining with genetic diversity based sampling proportion within group proportion. This sampling strategy was used to acquire the primary core collection of 64 accessions from 435 accessions of apple
cultivars, and the primary core collection could well represent the genetic diversities of the entire variety collection.