亚洲莲全基因组SSR的基本特征与遗传变异OA

To gain deeper insights into the genetic characteristics of simple sequence repeat(SSR)across the whole genome of Asian lotus(Nelumbo nucifera),33 representative accessions were used as materials.Whole-genome re-sequencing was used to analyze genome-wide SSR loci and their motif features,and to investigate the associations be-tween SSR genetic variation and phenotypic traits including germplasm origin,flower color,petal type,and ecotype.The results showed that the average number of SSR loci in the Asian lotus genome was 64 253.8,with a range of 25 961 to 119 777.Among the eight SSR types,namely imperfect(c*),compound(c),and mononucleotide(p1)to hexanucleotide(p6)repeats,p1 and p2 SSRs were the most abundant,accounting for 55.38%and 29.91%of the total,respectively.SSR counts exhibited a gradually increasing trend from wild types to modern cultivars and landraces;the number of SSR loci in double-petal lotus was 83 298.6,which was 1.6 times that of the single-petal type(51 874.6).No significant difference in SSR number was observed between temperate and tropical lotus.Per-fect p1 to p6 SSRs contained an average of 2.0,4.0,10.0,23.6,49.8,and 88.6 motif types,respectively,with the three most abundant motifs being A/T(52.173%),AG/CT(16.971%),and AT/AT(11.358%)in de-scending order.This study delineated the detailed differences in genome-wide SSR counts and motif composition among representative Asian lotus individuals,revealed a highly conserved proportional pattern across the eight SSR types,and suggested that hybridization and artificial selection have promoted both an increase in the number of ge-nomic SSR loci and an enrichment of their motif diversity.