Construction Of Genetic Linkage Map By SSR Markers And QTL Analysis Of Agronomic Traits In Peanut(Arachis Hypogaea L.)

Peanut (Arachis hypogaea L.) is self-pollinated plant, lack of the exogenous geneentrance, has low polymorphism at the DNA level, allotetraploid plant (2n=40), the numerouschromosomes has complicated structure. Genetic study on yield related traits started late andgot a slow progress. For the past few years, Quantitative traits analysis theory and molecularstudy provided a new way to comprehend the genetic development related yield and developthe QTL mapping analysis. A mapping population consisting of142F6-7individuals derivedfrom the cross between04D893and79266was used to establish a genetic linkage map ofcultivated peanut in this study. Major gene plus polygene mixed inheritance model and QTLlocation method was employed to analyze the14agronomic traits associated with leaf, planttype, pod and kernel in cultivated peanut. The main results were as follows:1、 On the basis of F6-7RIL (recombinant inbred lines)population derived from79266×04D893, statistic analysis was made aiming at14agronomic traits, the result showedthat: all the agronomic traits appears continuous variation and normal distribution except thetotal branch number. So those traits belong to quantitative traits, they are suitable to analyzethe genetic development and QTL location.2、The method of joint segregation analysis of multiple generations with P1、P2and F6-7of major gene plus polygene mixed inheritance model was used to analyze the yield traits inpeanut (2011and2012were as condition E1and E2respectively): on the condition of E1, leaflength, length of lateral branch, main stem height, total branch number, weight of per-kernel,thickness of pod shell and length of pod shell were controlled by three major genes. Leafwidth, pod number per-plant, single pod weight, width of pod shell and total pod weightper-plant were controlled by two major genes. On the condition of E2, leaf length, Podnumber per-plant, Weight of per-kernel, weight of per-kernel, thickness of pod shell andlength of pod shell were controlled by three major genes. Single pod weight and total podweight per-plant were controlled by two major genes. Main stem height and Total branchnumber was controlled by three major genes plus polygene. 3、A genetic linkage map of cultivated peanut including18linkage and92marker lociwas constructed by Join Map4.0. The linage map covers a total distance of516.7cM, themain distance is6.98cM between each two marker.4、50QTLs and49QTLs for these agronomic traits were identified by software QTL IciMapping and QTL Network2.0respectively.(1) QTL Ici Mapping detection result: On the condition of E1(in2011),28QTLsassociated with13agronomic traits were identified. Single QTL effect range from6.63%to50.95%, no QTL associated with length of pod shell was identified. On the condition of E2(in2012),22QTLs associated with12agronomic traits were identified. Single QTL effect rangefrom6.76%to63.10%, no QTL associated with single pod weight and weight of per-kernelwere identified. There were32SSR markers which closely linked QTLs obtained (geneticdistance of less than3cM).(2) QTL Network2.0detection result: there were49QTLs identified in total.30QTLsshowed additive effect,8pairs of QTLs showed epistatic effect,1pair of QTL showedadditive and environment interaction effect, one pair of QTL showed additive epistaticinteraction effect. Additive effect heritability ranges from2.24%to23.33%. Epistaticinteraction effect heritability ranges from2.51%to12.82%.(3) Two SSR markers that contains marker ARS370and marker F19were identified asrelated to the colors of endotesta and the plant type (quality traits) through linkage analysis byJoin Map4.0. The genetic distance between the two markers and controlling gene were6.1cM�'�15.8cM, respectively.