Initial Mapping Of Lobe-leafed Gene And Heterosis Utilization In Leaf Mustard

Mustard originated in China, mainly distributed in the central and Western of China、Australia and India and other regions.Margin lobe is a trait of leaves of Brassica juncea.Var,this trait makes leaves has many advantages,such as resistance to high temperature and water stress, the influence of specific leaf area、ventilation. Researchs on Margin lobe of leaves of Brassica juncea have not yet been reported, but leaves lobe of cabbage, rape, Arabidopsis, tomato and other species with a lot of reports. The purpose of this study is to investigated the laws of heredity of margin lobe gene and to carry out primary mapping of the gene, These results contribute to a theoretical basis and sources of material processing leaf mustard hybrids for Mustard divided leaves development 、 leaf lobes gene cloning 、 Heterosis breeding.Through the the cross between lobed leaf mustard and non lobed leaf mustard to get a leaf mustard strong heterosis combination,and analysis it,s quality of pickled processing. These results contribute to sources of material processing leaf mustard hybrids and a theoretical basis for the future development and. This study includes the following elements:1.Genetic characterization:Observation of lobed leaf mustard and non lobed leaf mustard;Construction of the six generations through lobed leaf mustard and non lobed leaf mustard, Record and analysis the segregation ratio of F2, BC1 groups between lobed leaf mustard and non lobed leaf mustard.The results showes that the leaf morphology of all F1 plants performan margin lobe, F2, BC1 separation of lobe leaf and non lobe leaf, the segregation ratio meets the Mendel genetic law of 3:1 and 1:1 with chi square. Genetic analysis suggested that the trait of Margin lobes was controlled by a pair of dominant nuclear gene,and named it Bj LB(Leaf-lobe in Brassica juncea).2.Primary mapping of margin lobe gene:Take the DNA of F2 and the two Parents as the template combined with BSA-Bulked Segregant Analysis method to screening SSR marker,in order to obtain Codominant markers. Verification F2 population with this marker,so as to carry out primary mapping of the margin lobe gene. We screened a linkage of molecular markers ACMP249,the margin lobes gene was located on brassica juncea chromosome 3,whose Physical mapping distanceon is 0.69 M regional from this microsatellite markers.3.High-throughput BSA sequencing: Selected lobed leaf mustard and non lobed leaf in each of 50 strains from the F2 generation, take the Leaf blade with hole method,lobed leaf of 50 strains of mixed as a kind and non lobed leaf of 50 strains of mixed as a kind, extraction RNA respectively for high-throughput BSA sequencing. The results of high-throughput BSA sequencing showes that the margin lobes gene was located on brassica juncea chromosome 10.4.Analysis of margin lobed related gene expression difference:According to the seven margin lobe gene have been reported to analysis of the conservative of margin lobe gene. Designed primer by the most conservative fragments,in order to analysis the expression difference between lobed leaf mustard and non lobed leaf mustard by Quantitative Real-time PCR. The results show that there is no significant differences of expression of gene expression in the two parents.Estimating Leaf-lobed gene Bj LB and these 7 genes are not the same gene.5.Utilization of heterosis:Based on twenty hybrid combinations were screened out of four Strong Heterosis Hybrid combination, with the lobed leaf mustard and non lobed leaf mustard as material through the method of cross combination,We get a leaf mustard strong heterosis combination(0912A×X2),and the combination’s heterobeltiosis of Important agronomic traits of plant weight is 51.11%; The fresh nutrient quality of protein and soluble solids perform positive over-standard heterosis, respectively 37.68%and34.57%.Based on the heterobeltiosis and over-standerd heterosis, further research on safety standards of nitrate and nitrite in combination pickled processing of this combination by orthogonal experimental design.Results showed :Marinated early( 0-15days) the optimal combination of low levels of nitrate contents is(A4D4B2E3C4), low levels of nitrite contents optimized combination is(B1C1D3A4E2); late pickled( 16-31days) low levels optimal combination of nitrate contents is(D1A4C3E4B1), optimized combination of low levels of nitrite contents is(C1A3E2B1D3).