Utilization of Diverse Germplasm for Soybean Yield Improvement

Abstract

Introgression of diverse germplasm into the current soybean [Glycine max (L.) Merr.J genetic base may increase genetic variability and lead to greater gains from selection. The objective of this research was to evaluate the genetic diversity and agronomic performance of experimental lines derived from plant introductions (Pis) maintained in the USDA Soybean Germplasm Collection. These Pis are known to be genetically distinct from the ancestors of the modern North American soybean cultivars. Experimental lines containing 25 to 100% PI germplasm (based on pedigrees), their parents, and recently released public cultivars were evaluated for yield in seven environments in 1994 and 1995. Data from random amplified polymorphic DNA (RAPD) fragments were collected and genetic relationships among all genotypes were estimated using hierarchical and nonhierarchical cluster analyses. Experimental lines were identified that yielded significantly more than their domestic parent. Comparisons of pairwise distances revealed that many of the high‐yielding experimental lines were more diverse than their domestic parents from the nonparental cultivars. The increased genetic diversity and yield provide evidence that exotic germplasm can contribute genes for high yield.