ARS | Publication request: SSR Marker Diversity of Soybean Aphid Resistance Sources in North America

Submitted to: Genome
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: October 5, 2007
Publication Date: December 15, 2007
Repository URL: http://hdl.handle.net/10113/37949
Citation: Chen, C.Y., Nelson, R.L., Gu, C., Mensah, C., Wang, D. 2007. SSR marker diversity of soybean aphid resistance sources in North America. Genome. 50 (12):1104-1111.

Interpretive Summary: The soybean aphid has become a major pest of soybean in North America since 2000. Seven aphid resistance sources, PI 71506, Dowling, Jackson, PI 567541B, PI 567598B, PI 567543C, and PI 567597C have been identified. Knowledge of genetic relationships among these sources and their ancestral parents will help breeders develop new cultivars with different resistance genes. The objective of this research was to examine the genetic relationships among these resistance sources. Sixty one lines were tested with 86 microsatellite DNA markers from 20 linkage groups of soybeans. Nonhierarchical and hierarchical clustering and multidimensional scaling (MDS) methods were used to determine relationships among the 61 lines. The 61 lines were clustered into four groups by both clustering methods and the MDS results consistently corresponded to the assigned groups. The 7 resistance sources were clustered into three different groups corresponding to their geographical origins and known pedigree information indicating genetic differences among these sources. The largest variation was found among individuals within different clusters by analysis of molecular variance.

Technical Abstract: The soybean aphid (Aphis glycines Matsumura) has become a major pest of soybean in North America since 2000. Seven aphid resistance sources, PI 71506, Dowling, Jackson, PI 567541B, PI 567598B, PI 567543C, and PI 567597C have been identified. Knowledge of genetic relationships among these sources and their ancestral parents will help develop new cultivars with different resistance genes. The objective of this research was to examine the genetic relationships among these resistance sources. Sixty one lines were tested with 86 simple sequence repeat (SSR) markers from 20 linkage groups. Nonhierarchical (VARCLUS) and hierarchical (Ward’s) clustering and multidimensional scaling (MDS) were used to determine relationships among the 61 lines. Two hundred and sixty two alleles of the 86 SSR loci were detected with a mean polymorphism information content of 0.36. The 61 lines were grouped into four clusters by both clustering methods and the MDS results consistently corresponded to the assigned clusters. The 7 resistance sources were clustered into three different groups corresponding to their geographical origins and known pedigree information indicating genetic differences among these sources. The largest variation was found among individuals within different clusters by analysis of molecular variance.