Genetic Analysis And QTLs Mapping Of Earliness Related Traits In Upland Cotton

Upland cotton(Gossypium hirsutum L.)is one of the main cultivated species,and it is also the largest cultivated area in china.Early maturing traits are important target traits in cotton genetic improvement.This study through the positioning of different groups of genetic analysis and QTL of Upland Cotton earliness related traits loci construction,aims to find the regulation of cotton earliness,provide favorable material for breeding practice later.The main results are as follows:1?In this study,we used the major gene polygene mixed genetic model to analyze the P1,P2,F1,F2 of the four generations of the combination I(CCRI60×CCRI50)and ?(CCRI41×CCRI74),and the cotton growth period traits: Flowering time(FT),Flowering and boll-setting period(FBP),Whole growing period(WGP)and plant characters: Node of first fruit branch(NFFB),Height of node of first fruit branch(HNFFB),Plant height(PH)are analyzed.The heritability of the major genes in the growth stages of the combination I was 63.002%,67.675%,and 60.872%,respectively,the heritability of polygene was 36.991%,32.325% and 39.125%,respectively;The heritability of the major genes in HNFFB and NFFB was 37.405%?23.194%,the heritability of polygene was 65.594%?76.805%;The heritability of the major genes in the growth stages of the combination ? was 64.298%?86.405%?70.837%,respectively,the heritability of polygene was 35.702%?13.595% and 29.163%,respectively;The heritability of the major genes in HNFFB and NFFB was 10.790%?4.570%,the heritability of polygene was 89.210%?95.430%;The heritability of polygene in PH of the two combination was 10.702%?42.263%,respectively.The heritability of the main genes controlling the growth traits was higher than that of the multiple genes.The heritability of the main genes controlling the plant type traits was lower than that of the polygene,indicating that the two hybrid combinations The main characters of the growth period were dominated by the main gene,and the plant type traits were mainly controlled by multiple genes,and further demonstrated that the precocious traits were simultaneously regulated by the host gene and multiple microbial genes.2?The F2 and F2: 3 isolates were constructed by using whole growth period of 98 days of early-maturing cotton variety CCRI50 and the whole growth period of 120 days of middle-mature cultivar CCRI 60 as parental hybrids.Using GBS to simplify the genome sequencing technology through the development of polymorphism markers between parents,and the classification of the mark after the abnormal base check,integrity filtration and partial separation marker filtration,Finally,5 114 SNP markers were obtained;3 167 BIN markers.The genetic map covering 26 chromosomes with total length of 2 878.696 cM was constructed by segregating population.The chromosome length was 28.433-284.656 cM,and the average distance between markers was 0.28-2.61 cM.On the land of cotton related traits: BP,FT,WGP,NFFB,HNFFB,FBP,PH of QTL detection.When LOD ? 2.5,a total of 70 QTLs associated with precocity were detected.Including 17 QTLs with phenotypic variation of more than 8%,Overlapping QTLs were found at 9 sites,The discovery of these loci laid the foundation for molecular marker assisted breeding of early maturing traits.