Inheritance Analysis And Gene Mapping Of Alb1 In Albino Pod Mutant Of Brassica Oleracea L.

Cabbage?Brassica oleracea L.var.capitata L.?is an important cruciferous vegetable crop grown worldwide.Seed pods of Brassica oleracea is generally green,albino is a harmful mutation,which can directly affect its normal seeding.But albino mutants of Brassica oleracea can be used to study chlorophyll synthesis,photosynthetic mechanism and albino gene function.In this study,the phenotypic characteristics and genetic rules of the pod of cabbage 16s569-4 were studied,and the genetic linkage map of the gene was constructed by combining BSA-Seq and InDel markers.The main research results are as follows:1.There was albinism in the seed pod at pod stage,and the rest of the plant was normal.According to the determination of pigment content of the pod of albino pod material 16s569-4 and green pod TO1000,chlorophyll a,chlorophyll b and carotene of 16s569-4 were significantly lower than that of TO1000.Paraffin section was used to observe the cell structure,and the results showed that the mutant cell wall was deformed,the cell boundary was not obvious,and the contour was not clear.The ultrastructure of chloroplast in 16s569-4 mutant was observed by electron microscope.2.16s569-4 and TO1000 were hybridized.The seed pods of F₁ plants are all green;the separation ratio is 3:1 between green pod and white pod in F₂ population.The separation ratio of green pod and white pod in BC₁P₁ group was 1:1.The chi square test??²?showed that the albino character of seed pod in16s569-4 was controlled by a recessive single gene,which was temporarily named alb1.3.F₂ obtained by hybridization between 16s569-4 and TO1000 was used as the mapping population,and the target gene was located in a physical interval of 0-3.79M by using the BSA-Seq technology.The high density genetic linkage map of alb1 was constructed by InDel markers.Finally,alb1 was located in the physical interval of 63.2 Kb between InDel markers yw31 and yw14 on chromosome 1.The gene sequences in the physical interval were analyzed,and there were 10 predictive genes in the 63.2 kb physical interval.A gene related to flower development,Bo1g005810,encoding non-apical meristem proteins,was found through gene function annotation,which may be the cause of seed pod albinism.Through sequence analysis of Bo1g005810,it was found that mutant 16s569-4 had 2 SNP mutations in the promoter region compared with green pod material TO1000,W4,W30 and W42.Therefore,Bo1g005810 was regarded as an important candidate gene.