[关键词]
[摘要]
自上世纪70年代以来,优质、抗逆、高配合力和适应性广的新种质匮乏,已成为影响玉米商业育种进一步发展的“瓶颈”。生产用种质的遗传脆弱性受到普遍关注,种质扩增、改良与创新成为作物育种研究最重要的发展方向。综述了CIMMYT和美国玉米遗传资源的搜集、评价、改良和利用情况,玉米遗传多样性的演变趋势与动力,杂种优势群和杂种优势模式研究进展,群体改良理论和技术的新发展及对杂种优势遗传机理的探索。Hallauer于2003年提出的两个杂种优势列(heterotic alignment)的概念,把对玉米杂种优势模式的认识从温带种质扩展到所有生态类型,为玉米种质扩增、改良和创新奠定了理论和方法学基础。两个群体间的相互轮回选择改良技术,是把种质资源大规模推向杂交育种应用的关键步骤。
[Key word]
[Abstract]
Scarcity of available germplasm with good quality, stress tolerance, higher combining ability and mega-environment adaptation has been being the bottle-neck in commercial maize breeding program since 1970’s. The genetic vulnerability of maize germplasm used in the development of commercial hybrids has been realized, and germplasm enhancement, improvement and development have been an important activity in maize breeding efforts. This review summarizes the germplasm collection, evaluation, improvement and utilization in CIMMYT and USA maize breeding program. Research progress on genetic diversity, heterotic groups and patterns, theory and technology of population improvement, and nature of heterosis are reviewed. The concepts of heterotic alignments by Hallauer in 2003 extended the utilization of the concepts of heterotic patterns to tropical and sub-tropical germplasm improvement from temperate maize breeding efforts, and established a theorical and methodological foundation for maize geremplasm enhancement, improvement and development. Reciprocal recurrent selection inter populations is the key step to use exotic germplasm and land races in development of hybrids.
[中图分类号]
[基金项目]