摘要
小麦作为人类最重要的粮食作物之一,面临大幅提高产量以满足人口持续膨胀的挑战,而杂交小麦被认为是提高小麦产量的首选途径.作为自花授粉作物,小麦杂交种的生产应用需要稳定的雄性不育母本和高效经济的杂交育种体系.相比其他雄性不育材料,小麦隐性细胞核雄性不育具有不育性稳定、恢复源广泛等优点,是建立杂交育种体系理想的母本材料.本文综述了近年来小麦隐性细胞核雄性不育突变体的研究进展,包括正向遗传学的基因克隆和通过基因编辑技术获得的多重突变体.本文详述了国内外通过染色体操作建立的小麦杂交育种体系,分析了各体系的优缺点及改进措施,以及利用分子设计育种建立的小麦第三代杂交育种体系的研究进展,并讨论了提高小麦杂种优势、降低杂交种生产成本和播种量的必要性与相应解决方案.
As one of the world’s most important staple crops,wheat breeders face the challenge of dramatically increasing wheat yield to meet the demand of the continually expanding human population.Hybrid wheat is considered to be the preferred approach to improve wheat yield.Because wheat is a self-pollinated crop,the production and application of hybrid wheat require a stable male-sterile female parent and a cost-efficient hybrid breeding system.Chemical hybridization agent(CHA)-induced male sterile lines,cytoplasmic male sterile(CMS)lines,and photoperiod/thermo-sensitive genic male sterile(PTGMS)lines have been successfully used as female parents for hybrid seed production.However,all of these strategies have limitations or production risks.Wheat recessive nuclear genetic malesterile mutants(also called non-conditional recessive nuclear genetic male-sterile mutants),by contrast,are more ideal female parents for establishing hybrid breeding systems because of their excellent characteristics,such as insensitivity to environmental and climate conditions and wide availability of restoration genes.Here we summarize the wheat hybrid breeding systems based on non-conditional recessive nuclear male-sterile mutants.The XYZ system was the first proposed system that was based on the recessive ms mutation on homeologous chromosome 5 and an alien chromosome 5R from rye(Secale cereale L.)possessing the corresponding Ms gene for fertility restoration and the marker gene Hp.The 4E-ms system and two other similar systems are updated versions of XYZ that are based on the ms1 mutation and an alien 4E chromosome from Agropyron elongatum ssp.ruthenicum that carries a gene homologous to Ms1 and the blue-aleurone(Ba)gene as a marker of the maintainer.However,there are some defects in these systems that result from the hereditary instability of the alien chromosome,such as the accumulation of the X line or dark blue seeds and the insufficient purity of the Z line or male sterile line.To improve the 4E-ms and similar systems,some modern technologies have been applied,such as introducing T-DNA carrying a pollen suicide gene and a seed fluorescence marker gene into the maintainer line,or using herbicide-resistant wheat as the male parent in hybrid production,or locating the Ms1 and Ba genes on the same chromosome by CRISPR/Cas9 technology.Other researchers have established a new system using the ms45 mutant instead of ms1 because both the homologous Ms45 gene and the Ba gene are located on the long arm of chromosome 4E.Similarly,the MNO system was proposed based on the triple mutant,in which the three copies of TIP2 on chromosomes 7A,7B,and 7D are mutated,and an alien chromosome 7H from barley,where the homologous TIP2 gene and the Waxy marker gene are located on the short arm of 7H.Furthermore,we outline the latest progress in third-generation hybrid wheat technology,also called seed production technology(SPT).This technology relies on transforming the male-sterile mutant with three closely-linked genes(a male fertility restoration gene,a pollen suicide gene and a seed color marker gene)to obtain a transgenic line which serves as the maintainer for the male sterile lines.The male-sterile plants that segregate from self-pollinated progeny of the maintainer would be used for hybrid seed production.Maximizing heterosis in wheat,increasing the yield of hybrid seed to reduce the cost of seed production,and reducing the amount of seed used are the three most important issues that determine the application of hybrid wheat.We discuss some possible solutions to promote commercial-scale application of hybrid wheat,such as identification of heterotic groups,improving outcrossing seed-set,breeding hybrid wheat varieties with higher tillering ability,and integrating efficient modes of cultivation and management.
作者
李健
周宽基
王峥
周君莉
邓兴旺
Jian Li;Kuanji Zhou;Zheng Wang;Junli Zhou;Xing Wang Deng(Peking University Institute of Advanced Agricultural Sciences,Shandong Laboratory of Advanced Agriculture Sciences in Weifang,Weifang 261325,China;Frontier Laboratory of System Crop Design,Beijing 102206,China)
出处
《科学通报》
EI
CAS
CSCD
北大核心
2022年第26期3140-3151,共12页
Chinese Science Bulletin
基金
山东省自然科学基金(ZR2021ZD30)资助。
关键词
小麦
隐性核雄性不育
外源染色体
杂交制种体系
wheat
recessive nuclear genetic male sterility
alien chromosome
hybrid seed production system
