SNP分子标记对bmr6和bmr12型褐色中脉高粱种质鉴定

Identification of the brown midrib genes bmr6 and bmr12 in Sorghum germplasms using an SNP marker

高粱(Sorghum bicolor)的褐色中脉(bmr)是由化学诱变引起,与传统的白色中脉相比能有效降低茎秆中木质素的含量,提高反刍动物的消化率。在高粱中已定位出8个bmr基因,其中只有bmr6和bmr12在生物学及分子水平方面得到全面的研究和广泛的应用。目前,有许多褐色中脉高粱种质资源,无法从中脉颜色上区分其基因型。因此,本研究根据bmr6和bmr12单碱基突变位点的DNA序列,利用单核苷酸多态性(SNPs)分子标记,对51份高粱种质中的褐色中脉类型进行鉴定,鉴定出bmr6型褐色中脉高粱种质24份,均为高代自交系材料;鉴定出bmr12型褐色中脉高粱种质2份(TxbmrB和Daka2BF9)。本研究鉴定出的bmr6和bmr12型褐色中脉高粱种质,可以为bmr饲用高粱新品种选育提供bmr性状供体创制相应的bmr亲本系材料,从而加快育种进程。此外,本研究优化了bmr6和bmr12 SNP分子标记体系,通过测序技术可快速准确地对bmr6和bmr12型褐色中脉高粱种质进行鉴定,从而加快bmr分子育种进程。

The brown midrib of sorghum was induced by chemical mutagens.Compared to the traditional white midrib sorghum,the brown midrib mutant can decrease lignin concentrations and enhance the digestibility of ruminants.Eight bmr genes have been identified in sorghum,of which bmr6 and bmr12 have been studied and widely used at a biological and molecular level.Currently,there is no method to differentiate the genotype of sorghum from the midrib color,with many germplasm resources of brown midrib sorghum.Hence,this study was performed based on the DNA sequence information of the bmr6 and bmr12 single-nucleotide mutations,using the biomarker technology of single-nucleotide polymorphisms(SNPs)to identify the bmr type individuals at the seedling stage in 51 sorghum germplasms.The results showed that 24 bmr6 sorghum germplasms were identified,which contained the high-generation inbred line material;two bmr12 sorghum germplasms(TxbmrB and Daka2BF9)were identified.The current study identified bmr6 and bmr12 sorghum germplasms that can serve as donors of the bmr trait for the breeding of new bmr lines,and be developed as corresponding bmr parent lines,so as accelerate the breeding process of new sorghum bmr lines.Therefore,this study optimized systems of the bmr6 and bmr12 SNP molecular marker systems that can quickly and accurately identify the germplasm of bmr6 and bmr12 by sequencing technology,thereby accelerating the molecular breeding process of sorghum bmr lines.