Construction Of Genetic Linkage Map Based On SSR Markers And QTLs Identification For Major Yield Traits In The Cultivated Peanut (Arachis Hypogaea L.)

Peanut is an important source of plant oil and protein. It’s one of the mostimportant oil and economic crops which is widely grown in the world. Cultivatedpeanut is allotetraploid crop(AABB,2n=4x=40).Peanut has rich variation inmorphology, physiology and agronomic traits, indicating that peanut should alsoexist in the larger variation at the DNA level. However because of the smallchromosomes, the complicated structure of gene and genetic research carried out toolate, the study of DNA molecular marker in peanut lags behind other crops at present.Along with the development of modern molecular biology technology and theapplication of high-throughput molecular marker technique, it is possible toconstruct genetic linkage map by using molecular markers. Capable of high-speedoperation of the computer and the development of software related maps, mapconstruction and QTL mapping which need large work become a reality. Peanutgenetic linkage map can be constructed using SSR molecular marker technology.With this map the morphlogy trataits related to yield can be QTL mapping andmolecular marker assisted breeding can be carried out. This will help to improve theefficiency of breeding and to speed up the process of breeding superior varieties inpeanut.In this study,215lines were RILs population extracted form a cross betweenBaisha1016and A.monticola. Using molecular markers technology and Joinmap4.0software, a genetic linkage map of this group was constructed. This map combinedwith phenotypic data for QTL mapping, thus we obtained a series of valuableresearch results as follows:1. A peanut genetic linkage map was constructed in this study which iscontained22linkage groups with282SSR markers. Total2405SSR makers wereused to screen this polymorphism. This map covered1440.4cM, the averagefigure for each of the two distance between markers was5.1cM. Number of markerson the linkage groups was from2to36and the length of each linkage group wasfrom236.3cM to3.2cM. In1,2,3,8,9,11linkage groups, there are differentdegrees of SSR marker dense region. 2. Based on these maps and field survey results,7yield traits including totalbranches,number of bearing branches, mature pods per plant,100-pod weight,100-seed weight, kernel percent and yield per plant were QTL mapping by usingCIM of WinQTLCart2.5software. In environment I (Zhengzhou),31QTLs weredetected for this seven traits, and a single QTL contribution rate was3.34%~24.22%.In environment II (Shangqiu),27QTLs were detected for this seven traits, and asingle QTL contribution rate was3.53%~15.90%. In environment III (Zhumadian),14QTLs were detected for six traits, and a single QTL contribution rate was4.06%~14.36%, while no QTLs were detected for total branches. Combined with theresults of three environment, QTLs which were near marker ARS445located onLg19, were closely linked with100-pod weight,100-seed weight and yield per plant,and all showed positive additive effect。...