中国玉米遗传单一性的经济影响

广泛采用少数优良种质资源，可能会引起作物遗传多样性下降，降低品种的抗病和抗逆能力，影响作物的产量。本研究采用系谱分析方法，研究了我国20个主产省玉米遗传单一性的变化及其对我国玉米生产的影响。结果表明，遗传单一性与玉米单产之间呈显著的负相关关系：遗传单一性每增加1%，玉米平均单产将降低13%；研究同时也表明遗传单一性和品种单一性是两个相互独立的变量，品种单一性不一定导致遗传基础的单一性。政府应从调节育种人员行为上制定相应的政策，防止遗传基础单一化，在增加作物遗传多样性的同时，选育优质高产的品种。

Impacts of genetic uniformity on maize production in China

Wide adoption of a few homogeneous lines of germplasm would reduce the genetic diversity of crops, and decrease their resistance and/or tolerance to biotic and abiotic stresses, and therefore reduce the stability of crop production. Based on analysis of pedigrees of varieties from 20 major maize producing provinces in China between 1982-1997, we studied economic impacts of genetic uniformity on maize production. The results indicate that there is a significant negative correlation between genetic uniformity and maize yield. One percent increase of genetic uniformity will cause 13% average yield decline. At the same time, the research also showed that genetic uniformity and variety uniformity are two independent variables. To enrich genetic diversity of the varieties, the government should make policies to increase breeder's incentives to develop new improved varieties using diverse materials.