Yield and Molecular Diversity of Soybean Lines Derived from Crosses of Northern and Southern Elite Parents

摘要

Genetic diversity is low in southern United States elite soybean [Glycine max (L.) Merr.] cultivars. Multiple sources of diversity will be required to effectively diversify this gene pool. The objective in this study was to evaluate the genetic diversity and yield of familiess derived from crosses between northern elite (NE) by southern elite (SE) parents. Lines were derived from 10 crosses of NE ?— SE parents. Molecular markers were used to estimate genetic distance between each line and its SE parent. Yield and agronomic traits were measured in field trials from 1997 to 1999 in six of the crosses. The association of diversity with line yield, expressed relative to yield of the SE parent was determined with regression. On average, the use of NE parents reduced yield, relative to using other SE parents. Some crosses and NE parents were better than others and produced families with yield that exceeded that of their SE parent, indicating that some genes from the NE parents were superior to the genes in the SE parent. At least one line with yield either superior or similar to their SE parent was found in each cross. The finding of positive transgressive segregants in some crosses and the results of the regression analyses indicate that most of the NE parents posses some yield genes that are likely to be superior to those of the SE parents. Our approach to selecting for diversity and yield may be applicable to large introgression programs where diversity from many sources is desired.