| As the main component of organic phosphorus,phytate-P hasbeen proved the potential phosphorus source to absorb and utilize for plants.Some researchsindicated that the acquisition and utilization of phosphorus was differencebetween genotypes of barley.Improving the acquisition and utilization abilities of P by the research of genetic mapping was an economical and environmental friendly approach to improve the nutritional status in barley.This study we has investigated the differences on phytate-P acquisition and utilization from different genotypes in barley.In addition,we created a high denisity genetic linkage map with the construction of DArT markers.Witha population consisting of 128 recombinant inbred lines(RILs),hydroponics and plot trials were conducted to detect QTLs for P efficiency traits in barley at thetillering and maturity stages.The major results in this research were as follows:(1)Maximum biomass was noticed at 30 mg kg-1 at three stages for three genotypes barley,the biomass of Baudin in the three stages were 1.30,1.22 and1.31 times of CN4027,respectively.With the increase of the concentration of phytate-P,P contents of three genotypes increased significantly.The phosphorus accumulation of Baudin,CN4079 and CN4027 reached the peak value at 30 mg kg-1,Baudin was significantly higher than CN4027,indicated that Baudin had stronger ability to accumulate phosphorus.The phosphorus utilization efficiency(PUE)of three genotypes decreased gradually with the increase of phytate-P,and the PUE for CN4027 was significantly higher than Baudin,indicated that CN4027 had stronger capacity to utilizate phosphorus.(2)Template by the genomic DNA of recombinant inbred lineswith 1281ines,we screened the polymorphism of Baudin and CN4027 through methods of analysis group strains of genotype by DArT marker.As a result,we received a total of 607 DArT molecular markers.The rest 177 markers were significant deviation and occupied 29.16%of the total number of markers.52 markers was Baudin,and 125 in favor of CN4027.Each chromosome has the distribution of segregation loci,and 6H was the most.A 607 DArT marker genetic map was constructed by mapping software JoinMap 4,which had a total length of 1148.70 cM and covered seven barley chromosomes.The single chromosome included 64?103 markers,contained length of 128.65?198.11 cM.And the average distance between markers was 1.89 cM.(3)Under the two phytate-P treatments,33 QTLs were detected on chromosomes 2H,3H,5H and 7H for P efficiency related traits.4 QTLs were related to PUE,explained 19.7%?30.3%of the phenotypic variation.One QTL related to PUP was located on 5H.4 QTLs were related to P content,explained 12.1%-21.7%of the phenotypic variation.7 QTLs were related to biomass and located on 3H and 5H.15 QTLs were detectedfor root morphology,explained11.9%-19.9%of the phenotype variation.One QTL cluster controlled PUE,biomass and P content were located in the interval bPb3263664-bPb3257096 on chromosome 3H.The other QTL cluster located in the interval bPb6270670-bPb3927065 on chromosome 5H was related to root morphology.(4)There were 27 QTLs detected on chromosomes 1H,3H,4H,5H and 7H,respectively.3 QTLs located on 3H,explained 11.6%-25.4%of the phenotype variation,the alleles for them were from CN4027.P content were located5 QTLs on 3H and 7H,alleles were all from Baudin.7 QTLs for biomass were located on 3H,5H and 7H,explained 12.3%?16.0%of the phenotype variation.11 QTLs for agronomic traitsexplained 11.1%?16.3%of the phenotypic variation.QTLs for PUE which located in the interval bPb3265414-bPb6283337 on chromosome 3H were detected at both phytate-P.And alleles for these QTLs were all from P-efficient parent CN4027,indicated that there might be a locus for controlling P efficiency in barley. |
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