Fine Mapping Of The Major QTL QPH3.2 And QPH3.3 For Plant Height In Maize(Zea Mays L.)

Plant height(PH)of maize is one major trait in maize breeding,which is highly correlated with mechanized harvest,lodging resistance and grain yield.In the previous study from our laboratory,two QTLs,q PH3.2(between marker C42 and P17)and q PH3.3(between marker C79 and C103),were mapped on chromosome3 using F2: 3 population,which was constructed from two advanced recombinant inbred lines(BCRIL)W1 and W2.In our research,the q PH3.2 and q PH3.3 were finally mapped in a little region with residual heterozygous line(RHL)population and recombinant lines.The main results obtained in this experiment are as follows:1? Remapping of the q PH3.2 using the remaining heterozygous group.The two remaining heterozygous individuals containing the target QTL were constructed from a selfing segregation population.The q PH3.2 include two QTLs according to composite interval mapping(CIM)and single marker analysis(SMA),named q PH3.2.1 and q PH3.2.2 respectively.The work validated the former work.2? Fine mapping of the q PH3.2.1.A total of 1765 individuals from the RHL were planted in two environment(Huanggang and Shandong)with three replication.The q PH3.2.1 was mapped between the markers Y72 and Y91 by progeny test.Then five kinds of recombinations were identified in the target region of Y72-Y91.Finally the q PH3.2.1 was mapped to a 7.6Mb region between the marker YH305 and Y72 by progeny test.3? Fine mapping the q PH3.2.2.A total 2125 individuals from the RHL were planted in two locations(Huanggang and Shandong)with three replications.The q PH3.2.2 was mapped between markers P17 and Y150 by progeny test.Then four kinds of recombination types were identified in the target region of P17-Y150.Finally the q PH3.2.2 was mapped to a 8Mb region that between the marker YH112 and Y150 by progeny test.4? Remapping of the qPH3.3 with RHL.Three remaining hybrids containing the target region were constructed segregating population.The CIM and SMA were used to remapping the q PH3.3.Our results validate the primery region that included a major QTL.5? Fine mapping the q PH3.3.According to the results of remapping,six reorganization individuals were identified in the target region.Investigating the important recombinant plants and their derived segregation populations suggested q PH3.3 was finally mapping between markers C79 and C90,which contained 11 Mb genomic region.