| Lodging is an important factor affecting maize yield and quality.The lodging of maize will affect the conduction tissue of the plant,change the distribution of the whole leaf of the plant in space,and decrease the photosynthesis efficiency of the leaf.The lodging site of stem is also easy to cause the infection of diseases and insect pests,and aggravate the loss of maize yield and stalk quality.Lodging trait is a complex quantitative trait.With the rapid development of molecular marker technology,a large number of lodging-related QTL have been identified.However,due to the different populations used by different researchers,the population size and mapping density are generally small,and so on.It is difficult to find molecular markers closely linked to lodging in maize,and few effective markers can be used in breeding process.Meta-analysis can be used to obtain more accurate linkage markers on the basis of integrating QTL from different sources,which is helpful to lodging resistance breeding of maize.On the basis of collecting the traits of lodging resistance-related QTLs in maize,the different molecular Markers-based QTLs were integrated into IBM Maize SNP50 reference spectra and IBM2 2008 Neighbors reference spectra respectively,and candidate genes related to lodging resistance in maize were excavated by meta-analysis and homology comparison with rice.The main results are as follows:1.A total of 128 QTL mapping articles related to lodging resistance traits in maize were collected,involving 164 locating populations and 2381 QTLs related to lodging resistance traits.There were 1610 lodging-related traits mapped on IBM2 2008 Neighbors map.Meta-QTLs of 90 plant type-related traits,42 stem-related traits,39 Root-related traits and 73 pest-resistant traits were obtained by meta-analysis.771 lodging-resistant traits were mapped on IBM Maize SNP50 reference map.Meta-QTLs of 82 plant type-related traits,51 stem-related traits and 43 Root-related traits were obtained by meta-analysis.Meta-QTLs with different related traits were concentrated in different chromosomes,and the overlapping regions of confidence intervals were dense.2.There were 909,1769 and 865 genes in the Meta-QTL region of plant type,stem and root related traits between two reference maps.2359 genes coexist in Meta-QTLs on IBM2 2008 Neighbors reference map and 23 QTLs mapped based on third-generation molecular marker mapping.3.Functional analysis showed that the common genes of plant type related traits were mainly related to ubiquitin ligase complexes and brassinolide metabolic pathways,which maintained normal plant growth and development and metabolic regulation.The common genes of stem related traits were mainly related to cellulose synthesis,sugar synthesis,propionic acid metabolic pathway and secondary metabolism.Metabolites and other processes;common genes of Root-related traits mainly involve cell formation processes such as intracellular,organelle and sphingolipid metabolism;common genes of pest-resistant traits mainly involve the synthesis of pest-resistant substances,including terpene synthase activity,terpenoids and secondary metabolites.GO enrichment analysis and Pathway enrichment analysis further clarified the functions and metabolic pathways involved in the lodging resistance of maize common genes.4.A total of 141 lodging-resistant genes were cloned from rice and 3 lodging-resistant candidate genes from maize roots.The NCBI website was used to compare the homology between cloned lodging resistance genes of rice and maize genome.27 candidate genes for lodging resistance of maize were found in four common genes of the same correlation traits in two reference maps,and one candidate gene for lodging resistance of maize was found in four common genes of IBM2 2008 Neighbors reference map. |
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