Exploration and utilization of maize male sterility resources.

Male sterility refers to the defective development of male reproductive organs, which led to plants incapable of producing normal and functional pollens. Maize (Zea mays L.) is one of the most important food crops, as well as one of the earliest crops to utilize heterosis in breeding. Single cross hybrid has been the main type of maize heterosis utilization for a long time. The planting area of maize hybrid in China has been stable at about 620 million mu. More than one billion kilograms of commercial hybrid seeds are needed each year, and the annual seed production area has been stable at about 2.5 million mu in recent years. So far, manual emasculation has been the major way of maize hybrid seed production in China, which is laborious and time consuming. Generally, spatial isolation is necessary for maize hybrid seed production, this requirement results in only some regions in the country suitable for maize hybrid seed production. Manual emasculation requires seasonal demand of labors. At present, with the urbanization of a large number of rural laborers, the seed production regions experience a serious labor shortage. Accordingly, the cost of seed production increases with the rising of land rent and labor costs. In addition, it is difficult to guarantee the seed purity with manual or mechanical emasculation for hybrid seed production. However, incorporating male sterility into maize hybrid seed production could reduce its cost and ensure hybrid seed purity. It can also avoid the difficulties of manual or mechanical emasculation in field operation under extreme weather conditions. Therefore, it is the inevitable trend of development in the maize seed industry. In this review, we summarize the exploitation and creation of maize cytoplasmic male sterility (CMS), maize genic male sterility (GMS) resources in China, and the developing process from natural discovery to targeted creation of male sterility resources in plants, and the research progress of maize male sterility. We then analyze the application status and existing problems of maize male sterility, based on the development trend of maize seed industry, as well as the research and application status of male sterility in China. We also identify seven aspects that need to be further strengthen, thereby providing the reference for the creation, research and utilization of maize male sterility in the future.植物雄性不育是指植物雄性生殖器官不能产生正常有功能花粉的现象。玉米(Zea mays L.)是重要的粮食作物之一,也是较早利用杂种优势的作物之一。当前,生产上广泛种植的玉米品种类型主要是单交种。我国玉米杂交种的播种面积常年稳定在6.2亿亩左右,年用种量10亿公斤以上,常年制种面积高达250多万亩。利用传统的人工去雄或机械去雄的制种方式进行杂交种子的生产,通常需要投入大量的人力、物力和财力。我国玉米制种基地具有明显的区域性,而玉米制种基地对劳动力的需求具有较强的季节性,当前伴随着大量农村劳动力的城市化转移,玉米制种基地出现了严重的用工慌,制种基地的租地费用和人工成本不断提高,使得种子生产成本不断升高。利用植物雄性不育系进行杂交种子的规模化生产,不仅能有效保证杂交种纯度,而且可以大大降低杂交种子的生产成本,同时还可避免极端天气条件下的人工去雄或机械去雄的田间操作困难等问题。因此利用雄性不育进行不育化制种是玉米种业发展的必然趋势。本文综述了我国玉米细胞质雄性不育以及包含光温敏雄性不育在内的细胞核雄性不育资源的发掘及创制进程、植物雄性不育资源从自然群体中获得到有目的性创制的发展过程及玉米雄性不育的研究进展,分析了玉米雄性不育的应用现状及存在的问题。基于我国玉米种业的发展趋势和雄性不育的研究及应用现状,提出了7个需要加强的方面,为玉米雄性不育的创制、研究和利用提供参考。.