| Wheat is one of the main crops in the world.Breeding wheat varieties with disease resistance and high yield has always been the focus of breeders.Fusarium head blight(FHB)is a worldwide fungal disease caused by the infection of a variety of Fusarium bacteria.It not only affects the yield and quality of wheat,but also affects food safety.It is known as a "cancer" of wheat,and its incidence and impact are particularly serious in China.Yangmai 12 is a variety with high yield,good stability,high resistance to powdery mildew,moderate resistance to FHB and resistance to lodging which was developed from powdery mildew resistance TP114(Pm2+6)as parent and Yangmai 158 as recurrent parent.Yanzhan 1 is a variety with early maturity,high yield,drought resistance and cold resistance but high susceptibility to FHB which was obtained by multistage cross between powdery mildew resistant variety C39 and an excellent parent with early maturity and high yield.Analysis of genetic basis of FHB resistance,plant height and heading day of Yangmai 12 and Yanzhan 1 could lay a foundation for molecular marker-assisted breeding of wheat.In this study,205 F10 generation recombinant inbred lines(RILs)were constructed with Yangmai 12 as the female parent and Yanzhan 1 as the male parent,and QTL mapping for FHB resistance,plant height and heading day was conducted based on phenotypic date from six environments.The main results are as follows:1、A genetic map containing 1482 linkage markers was constructed by using wheat 55 K gene chip,which contained 30 linkage groups and covered 21 chromosomes of wheat.The map length was 3719.62 c M,and the genetic density between markers was 2.51 c M.The chromosome length of group A was 1193.47 c M and contained 527 markers.The length of chromosome B was 1144.98 c M and contained 597 markers.The chromosome length of group D was 1381.17 c M and contained 358 markers.This map integrates known genes associated with disease resistance,quality,and yield in wheat that are polymorphic between parents.2、There were significant differences in percentage of scabbed spikelets(PSS),plant height and heading days between Yangmai 12 and Yanzhan 1.There was a significant negative correlation between PSS and heading days,but there was no significant correlation between PSS and plant height,and plant height and heading days in RILs.3、 A total of 18 stable QTLs were located based on the date from six environments by referring to the complete interval mapping method.There were five QTLs related to FHB resistance,eight QTLs related to plant height and five QTLs related to heading day.Five stable QTLs associated with FHB were located on chromosome 1A,1D,2B and 2D,respectively,explaining 2.56%-25.93% of phenotypic variation.QFHB-YU-2D.1 and QFHB-YU-2D.2 could be detected in two or more environments with higher effect values and the contribution rate is more than10%.QFHB-YU-2B could be detected in one environment and mean value,the contribution rate was 6.88%-9.08%,which might be a new resistance locus.Eight stable QTLs related to plant height were located on chromosome 2D,4B,4D,5A,5B and 7D(3),all QTLs could be detected in two or more environments and explained2.58% to 29.80% of phenotypic variation.QPH-YU-4B and QPH-YU-4D were the most stable QTLs and the highest contribution rate is more than 10%,the physical interval of these two QTLs wwere in the same interval with the two reported major dwarf genes Rht-B1 and Rht-D1.QPH-YU-2D,QPH-YU-5A,QPH-YU-7D.1,QPH-YU-7D.2 and QPH-YU-7D.3 had low contribution rate,and were speculated to be new plant height related QTLs.Five stable QTLs associated with heading stage were located on chromosomes 2B,2D,5B,7B and 7D,explaining 0.64% to 17.81%of phenotypic variation.The physical interval of QHD-YU-2B and QHD-YU-5B overlapped with the location of photoperiod gene Ppd-B1 and vernalization gene Vrn-B1.Both QHD-YU-2D and QHD-YU-7B could be detected in three environments and mean values.After comparison,it was speculated that QHD-YU-2D was an unreported heading day QTL.4、The locations of all trait related QTLS were analyzed,and two QTL intensive regions Q-YU-2D and Q-YU-7D were identified.Q-YU-2D was associated with FHB resistance and heading day.The FHB resistance allele and the additive effect of heading day came from Yangmai 12.The Q-YU-7D was correlated with plant height and heading day,and its additive effects also came from Yangmai12.5、The KASP marker KASP-2D was developed based on the closely linked SNP marker of Q-YU-2D.It was found that the detection results of the RIL population were consistent with those of the original chip.The results showed that the marker was reliable and effective,and could be used for molecular detection of Q-YU-2D allele. |
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