FINE MAPPINGA MAJOR BOLL WEIGHT QTL AND FINGERPRINT STUDIES IN UPLAND COTTON USINGs.pdf

1、Fine mapping a major boll weight QTL in upland cotton using SSRs.
　　Traits of agronomic importance, as outlined in other crops, are determined by the interactionsamong many associated components.Boll weight in cotton

2、is one of the yield associated traitswhich displayed composite inheritance pattern imputable to inherit complexity and allopolyploidnature of cultivated cotton.Molecular marker technology has broadened the method spectru

3、m fordetection, validation of quantitative trait loci (QTLs) and expression profiling of candidate genesconferring these QTLs.Bulk segregation Analysis (BSA) proposed an efficient strategy foridentifying DNA markers link

4、ed to the genes or genomic regions of interest.Many importantyield associated complex traits in plants were fine mapped and located on physical maps tofragments lengths of 10-100 Kb.Boll weight QTLs in cotton were mapped

5、 by many researchersusing different mapping populations and assigned to different linkage groups or chromosomes incotton genome.In present study, seventy-two bulk segregation primers were found and used togenotype F2-201

6、2 population.Major Boll weight QTL (qBW12) region was subjected to beenriched by SSRs present on both sides of flanking markers.Primers underlying and across bothsides of qBW12 were selected for further analysis in a rel

7、atively larger population (F2-2013) andflanked markers were detected (HAU4299 and Mon_DPL0493) for qBW12.The locus explained13.5％ of trait variation with a LOD peak of 14.82 and confidence interval 3.33 cM.Progenytesting

8、 of recombinants between adjacent markers, around flanking regions of the QTL, couldaid to further delimit qBW12.Chromosome 12 was found homologous to D0S, chromosomefrom D-genome progenitor of cultivated cotton, and con

9、sistently reported by many researchers asgene rich region.
　　Selection of core SSR markers for fingerprinting upland cotton cultivars and hybrids.
　　Precise identification of cotton cultivars and hybrids is requisi

10、te to facilitate management ofgermplasm resources and successful hybridization programs.Fingerprinting based on minimalcore set of highly informative primers will be more enlightening to unveil genetic constitutionamong

11、cotton cultivars and hybrids from distinct growing regions of china.Thirty-eight uplandcotton cultivars and 55 hybrids were selected from three cotton growing regions of chinamainland i.e.yellow river cotton valley (YRCV

12、), Yangtze river cotton valley (YzRCV) andnorth west dry region (NWDR); featured with perceptible climatology.Twelve randomlyselected cultivar and hybrids (representative sample of the three regions) were employed toreve

13、al polymorphism across mapped SSRs.Sixty-six genome-covered polymorphic SSRs wereemployed to assess genetic relatedness among all accessions.The results showed apolymorphism information content range from 0.34-0.86 and r

14、esolving power 0.04-2.45 forgenome-covered SSRs.Higher PIC and Rp values rendered selection of 13 highly informativepotential core SSRs, whose average PIC and Rp values were 0.80 and 1.64, respectively.Moreover, Jaccard'

15、s similarity coefficients of genome-covered and potential core SSRs werecompared and found to be related.Potential core SSRs substantiated clustering results ofgenome-covered SSRs and successfully discriminated all acces

16、sion.Overall clustering patternand revealed genetic constitution of tested material suggested that the 13 potential core SSRscould assure comparable results with higher resolution as compared to that of genome-coveredSSR