大豆细胞核雄性不育基因MS6的功能验证及不育新种质创制

Functional Identification of a Nuclear Male Sterility Gene MS6 and Creation of New Sterile Germplasms in Soybean

杂种优势利用是显著提高作物产量的有效途径之一,其中不育系的创制与利用,对作物杂交种的选育及生产起着至关重要的作用。基于细胞核雄性不育基因的作物杂交育种技术与传统杂交育种技术相比,具有制种安全、组合自由、杂交种育性稳定等优点,已在玉米、水稻等作物中广泛应用,这为大豆杂种优势利用提供了新思路。前期在大豆中图位克隆了1个编码R2R3-MYB转录因子的细胞核雄性不育基因MS6,本研究在此基础上,利用CRISPR/Cas9基因编辑技术,设计两个基因编辑靶点,在大豆品种Williams82中对MS6基因进行敲除;进一步通过对转基因后代植株的表型观察、花粉及育性鉴定、基因敲除位点分析,验证MS6基因调控大豆花粉形成及雄性育性的功能,最终获得稳定遗传的大豆ms6核不育新种质。这为进一步建立基于MS6基因的大豆第3代杂交育种技术系统,实现强优势杂交种的高效创制,提供了理论和技术参考。

Heterosis utilization is one of the effective ways to significantly increase crop yield,in which the creation and utilization of sterile lines plays a vital role in the breeding and production of crop hybrids.In contrast to the traditional hybrid breeding technology,the third generation crop hybrid breeding technology based on the nuclear male sterility gene has layers of advantages such as safety on seed production,flexibility on bi-parental combinations,and stability on hybrid fertility.This technology has been widely used in maize,rice and other crops,and provides a possibility in future use of soybean heterosis.We previously mapped by positional cloning approach a nucleic male sterility gene MS6 that encodes an R2R3-MYB transcription factor in soybean.In this study,we deployed CRISPR/Cas9 gene editing technology to design two gene editing targets to knock out the MS6 gene in soybean variety Williams82.The transgenic plants carrying edited MS6 alleles were subjected for phenotype observation,pollen and fertility identification,thus approving the function of this gene in regulating soybean pollen formation and male fertility.A new ms6 germplasm showing stable male sterility was obtained in soybean.This provides theoretical and technical support for further establishing the third generation soybean hybrid breeding technology system based on MS6 gene and realizing the efficient creation of strong heterosis hybrids.