Genetic Analysis And Gene Mapping Of A Yellow Green Leaf Gene (nec-t) In Maize

Maize is the most important source of food in the world. Its biomass and economic yieldmainly depend on the photosynthesis of leaves. The chlorophyll is an important pigment forphotosynthesis. Therefore it is very important in the theoretical research of photosynthesisregulatory mechanism to map and clone new photosynthetic-related genes and research theirfunction. Through the gene engineering approach the photosynthesis ability and economicefficiency of crops may be significantly increased.In this study the mutation of chlorophyll biosynthesis come form the natural mutant in maizeinbred line81647, it displayed yellow-green leaves at seeding stage and appeared necrotic spotson the leaves.The mutation nec-t crossed with B73,then the F1and F2generations were used toprocess genetic analysis and gene mapping，we discover and fine mapping the gene whichcontrolled the leaf color of the mutation nec-t.The results were obtained as following:1. Analyzed the phenotypic characteristics and measured the chlorophyll relative content ofthe mutation nec-t identified that the mutation was mutated in the step of chlorophyll biosynthesisand the phenotype of the mutation was impact by the illumination.2. F1and F2generation were got from cross between the mutant nec-t and B73.Observationshowed that leaf color of F₁progenies represented normal green and segregation ratio of normalgreen seedlings and mutant seedlings fitted the expected ratio of3:1in F₂population，whichsuggested that the yellowing trait of nec-t was controlled by one pair of recessive nuclear gene.3. The F₂population of380mutant plants was used to gene mapping. The gene nec-t wasrough mapped between SSR marker bnlg2277and mmc0111. This result provided a foundation offine mapping and map-based cloning of nec-t gene.4. Under the rough mapping, the population of1007mutant plants was used to find therecombinant plants for the gene nec-t, The bioinformatics technique was used to develop manyuseable marks in the main region. By detecting these recombinants plants,the gene nec-t wasmapped between mark H8and T31, which contained3BACs and it’s physical interval was 131.7Kb.