水稻分蘖角度基因TIG1功能性分子标记的开发和应用

Development and Application of Functional Molecular Marker of Rice Tiller Angle Gene TIG1

水稻分蘖角度是水稻株型建成的重要性状之一,对水稻产量有着重要的贡献。目前水稻中可利用的分蘖角度调控基因主要有TAC1(Tiller Angle Control 1)和TIG1 (Tiller Inclided Growth 1),需进一步挖掘新的可用基因资源和分子标记以促进水稻理想株型育种。本研究中以大角度的野生稻为供体,小角度的栽培稻珍汕97为受体构建了BC3F2群体,在第54号家系中分蘖角度存在分离,利用QTL-seq技术进行水稻分蘖角度的QTL定位,在8号染色体上检测到一个QTL位点。通过对区间内已知基因的序列比对提出TIG1为候选基因。根据TIG1启动子-449 bp处C?T的关键变异设计KASP功能性分子标记,并在定位群体和育成品种中进行了验证,证实利用该KASP标记可以准确地鉴定出TIG1位点的基因型。TIG1在粳稻中以大角度基因型TIG1占绝对优势,而在籼稻中61.40%的品种为小角度基因型tig1,38.40%的品种为大角度基因型TIG1,对水稻株型改良有着重要的潜在利用价值。该KASP标记的开发为水稻分蘖角度的分子标记辅助改良提供了新工具,有望加快水稻理想株型的育种进程。

The tiller angle is one of the most important traits in the plant architecture of rice,which significantly determines the rice yield.At present,the major tiller angle genes in rice are TAC1(Tiller Angle Control 1)and TIG1(Tiller Inclided Growth 1).It is necessary to further explore new loci and molecular markers to promote ideal plant architecture breeding in rice.In this study,a BC3F2 population was developed using large-angled wild rice as the donor and small-angled cultivar Zhenshan 97 as the recipient,and tiller angle separation was observed in the 54th line.QTL mapping of tiller angel was performed using QTL-seq,and a QTL was detected on chromosome 8.TIG1 was identified as the candidate gene through sequence comparison of known genes within the interval.A KASP functional molecular marker was designed based on the causal variation of C➝T at−449 bp in the promoter of TIG1.The marker was verified in the mapping population and varieties,and it was confirmed that the KASP marker can accurately identify the genotype of the TIG1 locus.In Geng/Japonica TIG1 with large angle is dominant,while 61.40%and 38.40%of Xian/Indica varieties carry tig1 with small angle and TIG1 with large angle,respectively.This marker has significant potential utilization value for improvement of rice plant architecture.The development of this KASP marker provides a new tool for molecular marker-assisted improvement of rice tiller angle and is expected to speed up the breeding process for the ideal rice plant architecture.