Genetic And Molecular Mechanism Of The Two Stamen Carpelloid Male Sterile Lines Of Brassica And The Key Locus Of AP3 Gene To Relevant To Petal Development

Using stamen carpelloid male sterile lines HGMS of Brassica chinensis and AMS of apetalous Brassica napus as materials, they were studied from genetics and molecular biology. Subsequently, transgenic researches were been done to discove the potential key locus of AP3 genes, which was probably related to petal formation. The main results as follows:1 Stamen carpelloid phenotype of HGMSa mutant wss controlled by two pairs of recessive genes, while stamen carpelloid phenotype of AMSa mutant was controlled by four pairs of recessive genes;2 There were two kinds of different AP3 genes, BAP3 and BAP3_-24, specifying petal and stamen development in Brassica. BAP3 shared higher homology with BAP3_-24 except one notable difference of 24 bp insertion at their C-terminus, but had a remarkable difference in their functions. BAP3 specified petal and stamen development, while BAP3_-24 only specified stamen development and has little effect on petal formation, but had dose effect in sepaloid petals development;3 Brassica chinensis contained one BAP3 gene and one BAP3_-24 gene. Loss-of-functions of the two AP3 genes thoroughly were the reason to stamen carpelloid mutant HGMSa;4 Brassica napus contained two BAP3 genes and two BAP3_-24 genes. Loss-of-functions of the two BAP3 genes were the key reason to causing Apt petal loss deficient. While loss-of-functions of all the AP3 genes were the primary reason to stamen carpelloid mutant AMSa of apetalous B.napus;5 Transgenic results inferred preliminary that the special 24bp sequence between BAP3 and BAP3_-24 was the key locus of AP3 gene to specify petal development.