Genotyping-by-sequencing of pear (Pyrus spp.) accessions unravels novel patterns of genetic diversity and selection footprints  

作　　者：Satish Kumar Chris Kirk Cecilia Deng Claudia Wiedow Mareike Knaebel Lester Brewer 

机构地区：[1]The New Zealand Institute for Plant&Food Research Limited,Hawke’s Bay Research Centre,Havelock North,New Zealand [2]Palmerston North Research Centre,Palmerston North,New Zealand [3]Mount Albert Research Centre,Auckland,New Zealand [4]Motueka Research Centre,Motueka,New Zealand

出　　处：《Horticulture Research》2017年第1期301-310,共10页园艺研究（英文）

基　　金：This research was partly supported by the New Zealand Ministry of Business,Innovation and Employment(MBIE).

摘　　要：Understanding of genetic diversity and marker-trait relationships in pears(Pyrus spp.)forms an important part of gene conservation and cultivar breeding.Accessions of Asian and European pear species,and interspecific hybrids were planted in a common garden experiment.Genotyping-by-sequencing(GBS)was used to genotype 214 accessions,which were also phenotyped for fruit quality traits.A combination of selection scans and association analyses were used to identify signatures of selection.Patterns of genetic diversity,population structure and introgression were also investigated.About 15000 high-quality SNP markers were identified from the GBS data,of which 25%and 11%harboured private alleles for European and Asian species,respectively.Bayesian clustering analysis suggested negligible gene flow,resulting in highly significant population differentiation(Fst=0.45)between Asian and European pears.Interspecific hybrids displayed an average of 55%and 45%introgression from their Asian and European ancestors,respectively.Phenotypic(firmness,acidity,shape and so on)variation between accessions was significantly associated with genetic differentiation.Allele frequencies at large-effect SNP loci were significantly different between genetic groups,suggesting footprints of directional selection.Selection scan analyses identified over 20 outlier SNP loci with substantial statistical support,likely to be subject to directional selection or closely linked to loci under selection.

关 键 词：planted directional LIKELY 

分 类 号：R74[医药卫生—神经病学与精神病学]