| Pre-harvest Sprouting at the mature stage of wheat refers to germination on the ear in rainy or humid environment before harvest,which is a worldwide natural disaster.The germination of wheat ears before harvest not only affects the yield,but also affects the quality,storage and sowing quality of the next year,resulting in different degrees of economic losses.In recent years,due to global warming and frequent extreme weather,the damage of ear germination is increasing.Therefore,how to control ear germination at the mature stage of wheat has become a major issue in wheat variety improvement,and it is also an urgent solution in wheat breeding and production at home and abroad.the problem.In this study,the "Yannong 999×Xinong 822" RIL population（180 copies）constructed by hybridization was used as the material,and the ear germination resistance was identified for two years.At the same time,based on the two-year phenotype data,combined with 55 K SNP gene chip to detect the population genotype,construct a high-density genetic map,map the QTL for panicle germination resistance in the RIL population,and develop corresponding molecular-assisted selection markers.The following conclusions were drawn:1.Both parents and 180 wheat materials were evaluated for PHS resistance in two fifield experiments and analyzed by variance.The results showed that the wheat ear germination resistance was mainly controlled by genetic factors and affected by certain environmental factors.2.By using 55 K gene chip to type the recombinant inbred lines constructed by Yannong999 and Xinong 822 and their parents,screening polymorphism markers and constructing a genetic map,finally a total of 14595 SNP markers were constructed on the linkage group,The markers covered 21 chromosomes in wheat with a total length of 16160.4 c M and an average density of 1.11 c M.Among them,the number of A,B and D genome markers are 5087（34.9% of the total markers）,5072（34.8% of the total markers）,4436（30.4% of the total markers）,and the lengths are 4544.4 c M,4587.0 c M,7029.0 c M,the average distance between markers was 0.89 c M,0.90 c M,1.58 c M,respectively,the polymorphic markers on chromosome 4D had the least distribution,only 255 SNP markers,while the polymorphic markers on chromosome 7B The most,up to 1190,is the largest number of markers on 21 chromosomes.3.Six QTLs controlling Pre-harvest Sprouting resistance were detected on chromosome1 D,2D,3A,4A,6D and 7D.QPhs.sdau-2D was detected between the markers AX-109836946 and AX-109785183 on chromosome 2D in both two years.The corresponding physical range was 32.16-46.87 Mb,which explained the phenotypic variation rate of 5.79%-10.07%,and the additive effect was all positive,suggesting that QPhs.sdau-2D was a stable inherited main effect QTL for anti-spike germination from yannong 999.4.According to the QTL mapping results,the SNP at the peak of the QTL with a larger effect value was converted into a KASP marker.Two KASP markers,KASP-AX-108908371 and KASP-AX-110647062,have been successfully developed and validated in this study.The KASP typing results are highly matched with the 55 K microarray typing results,and these markers can be well applied to related traits.In molecular marker-assisted selection breeding,a solid foundation has been laid for subsequent studies such as fine mapping and map-based cloning.5.By agronomic traits in the field investigation,the plant height,spike length,spikelet,spike grain number per plant,number of spikelets,grains per spike length,grain width,and eight important agronomic traits for data analysis,together with the previous two years Pre-harvest Sprouting resistance identification,through comprehensive evaluation selected six more excellent planting material,can be used as huanghuai wheat germplasm of Pre-harvest Sprouting resistance variety improvement and widely used. |
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