| Plant height is closely related to the lodging resistance,planting density and harvest index of Brassica napus(AACC,2n=38),and shorter stature is beneficial to mechanized harvesting.The morphological development of leaves is an important part of the ideal plant type,and the leaf shape has direct effects on photosynthesis,respiration and transpiration.In this study,the material named NJAU5737 with curved leaf and semi-dwarf stature has been researched.The SNP and SSR markers were used for mapping the Bn UC2/SD1 locus related to curved leaf and semi-dwarf stature,and the candidate genes were identified.The main results are as follows:(1)Inheritance of the curved leaf trait:Compared with Zhongshuang 11(ZS11),the NJAU5737 had deep-green leaf color and up-curved leaf phenotype at the seedling stage,and had shorter stature at the harvest stage.The F1(ZS11 × NJAU5737)exhibited the curved leaf and semi-dwarf stature phenotype.In the separation populations derived from consecutive selfing of cross(ZS11 × NJAU5737)F1 and backcrossing to recurrent parent ZS11,the curved leaf trait has been demonstrated to be controlled by one dominant gene.The locus related to curved leaf was named Bn UC2.(2)Gene mapping:By use of advanced populations derived from ZS11 and NJAU5737,BnUC2 locus has been finely mapped on A05 chromosome within an interval of 0.2 cM in length covering a physical distance of 94.53 kb in length.(3)Genetic analysis of plant height:After mapping the curved leaf trait locus,it was found to be a major quantitative locus for plant height trait in B.napus,explaining 67.11%of phenotypic variation of plant height.This locus mutation resulted in semi-dwarf stature.Thus,this locus may be named as BnUC2/SD1.(4)Analysis of agronomic traits:Analysis of the agronomic traits in the BC6 separation population indicated that the plant height,main inflorescence length and branch height of curved leaf and semi-dwarf plants has significantly reduced by Bn UC2/SDl,but the yield of plant with Bn UC2/SD1 locus did not change significantly.(5)Candidate gene analysis:The mapping interval contains six genes annotated,among which two genes BnaA05g16700D and BnaA05g16720D may be regarded as candidate genes responsible for the mutation trait.The overexpression and RNAi expression vectors for these two genes has been constructed. |
