Impacts of genetic uniformity on maize production in China
中国玉米遗传单一性的经济影响

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.