Comparative analysis of core collection sampling methods for mandarin germplasm based on molecular and phenotypic data

In this study, several software packages (DARwin, PowerMarker and MSTRAT) and methods (Max length subtree, M strategy, simulated annealing and MinSD) were compared to define a mandarin (Citrus reticulata) CC. One hundred and sixty‐seven accessions were sampled from two germplasm collections, which were genotyped with 50 SSR, 24 InDel and 68 single nucleotide polymorphism markers. All the CC obtained were tested for the maintenance of the genetic variability parameters (Ho and He) of the initial collection, the level of linkage disequilibrium (LD) and the phenotypic diversity retention. The Max length subtree function from DARWin seemed to be the most appropriate method for establishing a CC in C. reticulata. It maintained 96.82% of the allelic richness and 17.96% of the size of the initial collection with only 30 accessions. Besides it did not increase the LD (r2 value) of the initial collection and retained the vast majority of the phenotypic variability. However, a CC with 70 accessions would be more helpful for genetic association studies. Comparative results of the core collection sampling methods in the two sizes selected (χ2, P < 0.05). Germplasm collections are established to maintain the genetic diversity of the crops. When they are huge and are species with recalcitrant seeds as citrus, their maintenance, costs, space and so on become a problem. To reduce their size, but maintaining their diversity, core collections are being developed.
Source: Annals of Applied Biology - Category: Biology Authors: Tags: RESEARCH ARTICLE Source Type: research