Analysis On Agronomic Traits Of Germplasm Resources And QTL Mapping In Adzuki Bean(vigna Angulariss)

Adzuki bean,one of important pulase crop,originated in China and was domestidated about12,000 years ago.Phenotypic data of 660 germplasm resources in wild and cultivated adzuki bean were analyzed.The results showed that growth period shortened,the plant height became dwarf,pod number per plant and yield per plant decreased,and 100-seed weight increased in the process of domestication.Stem color is changed into green from purple,and plant is evolved from the creeping into the upright.Pod color become straw from black.Seed coat color turn into red from grey with sparsely black mottle or black.There were correlation between the phenotypic traits.Yield should be effectively increased,and elite variety with desirable traits could be bredby increasing the plant height,pod number per plant and the total seed number per plant.Mapping population of F₂ was constructed between a cross of Chinese cultivated adzuki bean Ass001 and wild adzuki bean accession no.CWA108.133.93G bases?raw data?were generated,and 3,617 segregated SNP sites were identified via restriction-site associated DNA-sequencing?RAD-Seq?.1571 polymorphic SNP markers were used to construct a high density genetic map.Total length of the map was 1031.171 cM,and 1571 SNP markers covered 11 linkage groups with an average of 142.818 markers on each chromosome.The length of the linkage map was 45.72¹28.24cM.The SNP markers were distributed in all areas of the linkage group.The average length of each chromosome was 93.743 cM.The average distance between markers is 0.656 cM.The scaffold length on each chromosome is between 19.36 and 422.25 Mb with a total length of372.88 Mb.Agronomic trait QTL was mapped using F₂,F₃ and F₄ population derived from the cross of Ass001×CWA108.A total of 26 QTL from 11 agronomic traits,including flowering time and pod maturing time,100-seed weight,maximum leaf width,branch number on the main stem seed number per pod,and seed thickness were detected in the 8 linkage groups except chromosome 5,6 and 8,and most of these QTLs located on chrosome 4.The proportion of phenotypic variation explained?PVE?was from 4.1%to 73.1%.Eleven QTLs for flowering time and pod maturity on chromosomes 4,7,and 10 were mapped.Two major flowering time QTLs on chromosome 4,firstly VaFld4.1?PEVs 71.3%?,were co-segregated with SNP markers s690-144110,and VaFld4.2?PEVs 67.6%?had a 0.974 cM genetic distance with the SNP marker s165-116310.Six 100-seed weight QTLs were detected on chromosomes 1 and 11,three QTLs for branch number on the main stem were detected on chromosome 4.Three QTLs for seed number per pod?VaSnp3.1,VaSnp3.2and VaSnp4.1?were mapped on chromosomes 3 and 4,and VaSnp4.1?PEVs 11.8%?were co-segregated with SNP markers s80-1776704.QTLs VaLfmw2.1 for maximum leaf width on chromosomes 2 was co-segregated with s536-414880,and stem internode length QTL VaST1-10I9.1 on chromosomes 9 was co-segregated with SNP marker s249-3204596.One QTL VaSdt4.1 of seed thickness on chromosomes 4 was co-segregated with s58-1489334.Three candidate genes,VaAGL,VaPhyE,and VaAP2,were identified for flowering time and pod maturity in QTL mapping region of flowering time and pod maturity.VaAGL encodes an agamous-like MADS-box protein of 379 amino acids.In total,29 Agamous-like MADS-box genes were found in the adzuki bean genome.VaPhyE encodes a phytochrome E protein of 1,121 amino acids.Four phytochrome genes?VaPhyA1,VaPhyA2,VaPhyB,and VaPhyE?were identified in the adzuki bean genome.Two candidate genes VaAP2/ERF.81 and VaAP2/ERF.82 of 100-seed weight?SD100WT?,a VaAP2-s4 of seed thickness?SDT?,and VaAP2/ERF.86 of maximum leaf width?LFMW?were also detected.In total,26 AP2/ERF genes were identified in the adzuki bean genome.