Identification of S-Rnase genotype and analysis of its origin and evolutionary patterns in Malus plantsOA北大核心CSTPCD

Identification of the S genotype of Malus plants will greatly promote the discovery of new genes,the cultivation and production of apple,the breeding of new varieties,and the origin and evolution of self-incompatibility in Malus plants.In this experiment,88 Malus germplasm resources,such as Aihuahong,Xishuhaitang,and Reguanzi,were used as materials.Seven gene-specific primer combinations were used in the genotype identification.PCR amplification using leaf DNA produced a single S-RNase gene fragment in all materials.The results revealed that 70 of the identified materials obtained a complete S-RNase genotype,while only one S-RNase gene was found in 18 of them.Through homology comparison and analysis,13 S-RNase genotypes were obtained:S1S2(Aihuahong,etc.),S1S28(Xixian Haitang,etc.),S1S51(Hebei Pingdinghaitang),S1S3(Xiangyangcun Daguo,etc.),S2S3(Zhaiyehaitang,etc.),S3S51(Xishan 1),S3S28(Huangselihaerde,etc.),S2S28(Honghaitang,etc.),S4S28(Bo 11),S7S28(Jiuquan Shaguo),S10Se(Dongchengguan 13),S10S21(Dongxiangjiao)and SeS51(Xiongyue Haitang).Simultaneously,the frequency of the S gene in the tested materials was analyzed.The findings revealed that different S genes had varying frequencies in Malus resources,as well as varying frequencies between intraspecific and interspecific.S3 had the highest frequency of 68.18%,followed by S1(42.04%).In addition,the phylogenetic tree and origin evolution analysis revealed that the S gene differentiation was completed prior to the formation of various apple species,that cultivated species also evolved new S genes,and that the S50 gene is the oldest S allele in Malus plants.The S1,S29,and S33 genes in apple-cultivated species,on the other hand,may have originated in M.sieversii,M.hupehensis,and M.kansuensis,respectively.In addition to M.sieversii,M.kansuensis and M.sikkimensis may have also played a role in the origin and evolution of some Chinese apples.