| Wheat is one of the most widely planted staple crops in China.The growth of wheat is significantly affected by abiotic stresses such as extreme weather.Strong winds and rainfall are the main causes of lodging and yield reduction.Therefore,improving the lodging resistance of wheat is very important for wheat production.Lodging not only damages the morphological structure of plants,reduces photosynthetic capacity and production of photosynthetic products,but also affects the transportation of water and photosynthetic products,thereby affecting grain filling.At the same time,lodging will also affect grain quality.Lodging is divided into stem lodging and root lodging.Root lodging is usually due to thin soil layer and shallow plow layer,which cause the wheat to take root weakly.In actual production,the probability of root lodging is very small,so the research on wheat lodging resistance mainly focuses on stem lodging.Stem strength refers to the ability of stems to resist external force without deformation or fracture.It is affected by genetic and environmental factors and is an important indicator to measure the lodging resistance of plants.In this study,140 offspring of recombinant inbred lines constructed by Annong0711 and Henong 825 were used as test materials,and the stem strength values under multi-year multi-point environments were counted as the lodging resistance evaluation index.At the same time,wheat 55 K chip polymorphic Sexual SNP markers were used to analyze their genotypes.Using the complete interval mapping method of QTL Ici Mapping v4.1 software to identify the main effect loci of stem strength;combined with the physical map of the reference genome,the relevant gene screening and mining of the target segment were carried out,and relevant molecular markers were developed and included in 104 germplasm resources.authenticating.The main results are as follows:1.The variation range of stem strength in the offspring materials of AH-RILs population is relatively large,and there are different degrees of two-way superparent segregation in the offspring.The stalk strength changes in the 7 environments showed a continuous distribution,all of which showed normal distribution,and the correlation of stalk strength among the 7 environments reached a very significant level(P<0.01).The performance is relatively stable.2.The parents and RIL families were genotyped by wheat 55 K microarray technology,and 11,173 dimorphic SNPs were screened out.After linkage analysis,a high-density genetic map was constructed,with a total length of 5889.79 c M and an average distance between markers of 3.74 c M.Using QTL Ici Mapping v4.1 to conduct QTL mapping analysis on stalk strength and constructed genetic maps in 3 years and 7 environments,a total of 64 QTLs were detected,distributed on the other 17 chromosomes except 1A,1B,6A and 7A.on a chromosome.A single QTL explained 6.05-69.22% of the phenotypic variation,and the additive effect was(-1.9)-0.51 N.Among them,21 QTLs could be detected in 2 or more environments.Except for Qss.ahau-3B.1,the additive effects of the other 60 QTLs were all from Annong 0711.3.Using AH-RILs population combined with wheat 55 K microarray data,a total of 64 QTLs were detected,and a major QTL locus(Qss.ahau-1D.1)was identified on chromosome 1D that stably existed in 7 environments.The phenotypic variation in stem strength can be explained by 9.11-13.56%,and the additive utility is 0.14-0.24 N.The potentiating alleles are all from Annon 0711,flanking markers are AX109862278 and AX109864616,and the physical interval is 4.96 Mb(335.59-340.55 Mb).This site was compressed to a physical interval of 2.56 Mb using developed molecular markers.4.Based on the molecular marker developed by the dimorphic SNP in the Qss.ahau-1D.1 site,104 germplasm resources can be divided into 2 haplotypes(Annong 0711 type and Henong 825 type),And the results of U test showed that these two haplotypes had significant difference(P<0.05)or very significant difference(P<0.01)in the stem strength phenotype of different germplasm resources.Among them,29 germplasm resources from different wheat regions all carried excellent allelic variation.The results of this study can provide important resistance resources and effective molecular marker information for accelerating the genetic improvement of lodging resistance in wheat. |
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