外来种质对中国玉米生产的遗传贡献

The Impacts of US and CGIAR's Germplasm on Maize Production in China

广泛采用少数优良种质资源,会引起作物遗传多样性下降,降低品种抗病和抗逆能力,影响作物的产量。引进和利用外来种质资源是丰富作物遗传多样性、促进品种更新换代的重要途径。通过分析中国20个玉米主产省区15年(1982～1997)主要品种的亲缘关系和遗传构成,研究外来种质资源,特别是美国和国际农业研究磋商组织(CGIAR,以下简称CG系统)对中国玉米遗传贡献的时空变化和对中国玉米生产的经济影响。结果表明,美国种质和CG系统的种质对中国玉米的遗传贡献一直呈增长趋势,尤其是CG系统的遗传贡献从20世纪90年代以来增长迅速;美国遗传贡献率每增加1%,中国玉米单产将提高0.2%或者0.01t·ha-1;CG系统遗传贡献每增加1%,玉米单产将提高0.025t·ha-1,高于美国种质对中国玉米产量潜力的作用。中国政府应支持和鼓励研究人员在引进与利用美国种质的同时,加强对来自CG系统种质的研究、开发与利用,从而更好地为中国玉米生产的发展提供资源储备。

Wide adoption of a few of homogeneous germplasm would reduce crops＇ genetic diversity, increase crop vulnerability stresses, and reduce the stability of crop production. The introduction and utilization of exotic gerrnplasm is a sustainable solution for broadening the genetic diversity and promoting periodical replacement of varieties. The genetic contribution and economic impacts of exotic genetic resources （particularly that of US and CG resources） on China＇s maize production were evaluated on the basis of analysis of varieties＇ pedigree information from 20 major maize-producing provinces in China from 1982 to 1997. The results indicated that the contribution of US and CG germplasm resources to the continuous increase of China＇s maize production, particularly CG gerplasm resources, has shown a rapid increase trend since the 1990s. The genetic contribution of US germplasm resources increase by 1%, per unit maize yield will increase by 0.2% （0.01 t.hal）. If the contribution of CG germplsam resources, which has greater potential yield, increase by 1%, maize yield will increase by 0.025 t·ha^-1. One policy should be implemented for the government is encouraging breeders to focus more attentions on the use and improvement of CG germplasm resources. The US germplasm resources have been utilized extensively in China so that they can offer germplasm resources for maize breeding and maize production.