QTL Analysis Of Maize Leaf Main Vein Characters Based On PH4CV/HG8 Linkage Population

Maize(Zea mays L)is an important food crop and cash crop in China,and also the most widely planted crop in China,At present,the demand of maize in our country is increasing gradually,but the cultivated land area is decreasing gradually because of land pollution,population increase and other reasons.The contradiction between the increasing demand for grain and the decrease of available arable land gradually deepens,so it is urgent to cultivate maize varieties with high yield per unit area.Maize leaf is the main photosynthetic organ of maize,and the growth and development of maize leaf also affect the growth and development of the whole plant and the accumulation of nutrients.Leaf veins are the main organs for transporting water,nutrients and photosynthetic products,so genetic analysis of maize leaf veins could lay the foundation for breeding maize varieties with better plant type.Previous studies focused on the phenotypic traits of maize veins.QTL(quantitative trait locus)analysis of leaf main vein-related traits such as leaf main vein thickness,main vein width,and main vein depth of BC2S6 population composed of PH4 CV and HG8 hybrids.The candidate genes of maize main vein related traits,such as main vein thickness,main vein width and main vein depth,were mined to provide theoretical support for the rapid screening of maize varieties with good plant type.The main results of this study are:1.The three main leaf vein traits of the linkage group: the generalized heritability of BLUP of main vein diameter,main vein width,and main vein depth are 0.62,0.52,and 0.71,respectively,all of them had medium heritability,and the value of genetic variance was much higher than that of environmental variance,indicating that the main vein thickness,main vein width and main vein depth of maize were mainly characters controlled by heredity.2.The results showed that the traits of the three main veins of maize all presented normal distribution,indicating that the traits of the main vein accord with the genetic characteristics of quantitative traits.On main veins data correlation analysis results show that each character in shenyang and fuxin and BLUP(Best Linear Unbiased Prediction)between both show significant correlation,and Pearson correlation coefficient is higher,shows good repeatability of each character in different locations.3.QTL analysis of main vein thickness,main vein width and main vein depth of maize showed that a total of 13 QTLS were detected in the analysis of main vein thickness of maize,located on chromosomes 4,6 and 7.The phenotypic contribution rate ranged from 3.1% to 10.6%.4.A total of 180 candidate genes were mapped in this experiment,and they were located on chromosomes 4,6,and 7 respectively.Genes GRMZM2G015295,adjust the leaf area of plants,have important significance for the development of plant leaves;genes GRMZM2G074427 is mainly involved in auxin response and regulates plant growth and development;genes GRMZM2G050939 belongs to the PP2 C family and has a special structure and function in the protein phosphatase family,which controls the growth and development of plants,including the formation of roots,leaf senescence,seed germination,and stomatal development,and plays an important role in plant growth;genes GRMZM2G014119 encodes a ubiquitin-like protein,its homolog in Arabidopsis(AT1G31340.1)encodes a ubiquitin-like protein RUB1,which binds to the target protein and participates in the auxin response;genes GRMZM2G146140 belongs to the Zm HAK family and is involved in important physiological processes of plants;genes GRMZM2G146190 belongs to the cyclophilin family,participates in cell division,protein folding and other activities,and participates in plant growth and development regulation;genes GRMZM2G024437 belongs to the ANK domain,and a few plant ANK proteins have functional characteristics and play a role in cell growth and development(such as cell signal transduction and cell cycle regulation);genes GRMZM2G100107 is annotated as a SANT domain-related protein and has an important effect on disease resistance;these genes play a vital role in the growth of plant leaves and veins.