Page Banner

United States Department of Agriculture

Agricultural Research Service

Research Project: IMPROVEMENT OF PEST RESISTANCE AND QUALITY TRAITS OF SOYBEAN

Location: Corn, Soybean and Wheat Quality Research Unit

Title: Identification of quantitative trait loci conditioning partial resistance to Phytophthora sojae in soybean PI 407861A

Authors
item Lee, Sungwoo -
item Mian, Rouf
item Mchale, Leah -
item Sneller, Clay -
item Dorance, Anne -

Submitted to: Crop Science
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: February 15, 2013
Publication Date: April 6, 2013
Repository URL: http://handle.nal.usda.gov/10113/58211
Citation: Lee, S., Mian, R.M., Mchale, L.K., Sneller, C.H., Dorance, A. 2013. Identification of quantitative trait loci conditioning partial resistance to Phytophthora sojae in soybean PI 407861A. Crop Science. 53(3):1022-1031.

Interpretive Summary: Soybean resistance to Phytophthora root and stem rot, caused by Phytophthora sojae, is an economically important trait. Partial resistance can be as effective in managing this disease as single-gene (Rps) mediated resistance and is more durable. The quantitative trait loci (QTL) conferring partial resistance to Phytophthora sojae was mapped with molecular markers in an OX20-8 × PI (Plant Introduction) 407861A cross, where PI 407861A was used as the source of partial resistance. One hundred fifty-seven F7–derived recombinant inbred lines (RILs) were evaluated for partial resistance to P. sojae isolate OH25 using tray tests. Molecular mapping identified nine QTL on soybean chromosomes 3, 4, 8, 10, 13, 15, and 18. The phenotypic variance explained by individual QTL ranged 2.4 to 8.6 %, with a total of 44 %. Two QTL on chromosome 3 and 8 are novel QTL first reported for partial resistance to P. sojae in this study. All nine QTL were localized near known R-gene rich regions and previously reported QTL for resistance to soil-borne pathogens. Genome-wide distribution of those QTL in this population was distinct from the QTL identified in Conrad populations. Results indicate that South Korean soybean PIs may carry distinct genes for partial resistance that are different from genes present in North American cultivars. These results indicate that PI 407861A is a promising genetic source of alleles that can be used to enhance levels of partial resistance to P. sojae in soybean cultivars. This PI can also be used as a source to increase genetic diversity for partial resistance to P. sojae in the North American soybean cultivars in general.

Technical Abstract: Improving resistance for Phytophthora root and stem rot is an important goal in soybean [Glycine max (L.) Merr.] breeding. Partial resistance can be as effective in managing this disease as single-gene (Rps) mediated resistance and is more durable. The objective of this study was to identify QTL conferring partial resistance to Phytophthora sojae in an OX20-8 × PI 407861A cross, where PI 407861A was used as the source of partial resistance. One hundred fifty-seven F7–derived recombinant inbred lines (RILs) were evaluated for partial resistance to P. sojae isolate OH25 using tray tests. Composite interval mapping identified nine QTL on chromosomes 3, 4, 8, 10, 13, 15, and 18. The phenotypic variance explained by individual QTL ranged 2.4 to 8.6 %, with a total of 44 %. Two QTL on chromosome 3 and 8 are novel QTL first reported for partial resistance to P. sojae in this study. All nine QTL were localized near known R-gene rich regions and previously reported QTL for resistance to soil-borne pathogens. Genome-wide distribution of those QTL in this population was distinct from the QTL identified in Conrad populations, while many QTL in common with QTL identified in a population derived from crosses with another South Korean soybean accession, implicating underlying genes for partial resistance in these exotic genotypes may be distinct from genes controlling variation for partial resistance observed in North American cultivars. These results indicate that PI 407861A is a promising genetic source of alleles that can be used to enhance levels of partial resistance to P. sojae in soybean cultivars as well as increase genetic diversity for partial resistance to P. sojae in the North American soybean cultivars.

Last Modified: 4/19/2014
Footer Content Back to Top of Page