Theoretical and Applied Genetics

, Volume 116, Issue 7, pp 967–977

Separate loci underlie resistance to root infection and leaf scorch during soybean sudden death syndrome

Authors

  • S. Kazi
    • Plant Biotechnology and Genomics Core-Facility, Department of Plant, Soil, and Agricultural SystemsSouthern Illinois University
    • Center for Excellence in Soybean Research, Teaching and OutreachSouthern Illinois University
  • J. Shultz
    • Plant Biotechnology and Genomics Core-Facility, Department of Plant, Soil, and Agricultural SystemsSouthern Illinois University
    • Center for Excellence in Soybean Research, Teaching and OutreachSouthern Illinois University
    • School of Biological SciencesLouisiana Tech University
  • J. Afzal
    • Plant Biotechnology and Genomics Core-Facility, Department of Plant, Soil, and Agricultural SystemsSouthern Illinois University
    • Center for Excellence in Soybean Research, Teaching and OutreachSouthern Illinois University
  • J. Johnson
    • Plant Biotechnology and Genomics Core-Facility, Department of Plant, Soil, and Agricultural SystemsSouthern Illinois University
  • V. N. Njiti
    • Plant Biotechnology and Genomics Core-Facility, Department of Plant, Soil, and Agricultural SystemsSouthern Illinois University
    • Department of BiotechnologyAlcorn State University
    • Plant Biotechnology and Genomics Core-Facility, Department of Plant, Soil, and Agricultural SystemsSouthern Illinois University
    • Center for Excellence in Soybean Research, Teaching and OutreachSouthern Illinois University
Original Paper

DOI: 10.1007/s00122-008-0728-0

Cite this article as:
Kazi, S., Shultz, J., Afzal, J. et al. Theor Appl Genet (2008) 116: 967. doi:10.1007/s00122-008-0728-0

Abstract

Soybean [Glycine max (L.) Merr.] cultivars show differences in their resistance to both the leaf scorch and root rot of sudden death syndrome (SDS). The syndrome is caused by root colonization by Fusarium virguliforme (ex. F. solani f. sp. glycines). Root susceptibility combined with reduced leaf scorch resistance has been associated with resistance to Heterodera glycines HG Type 1.3.6.7 (race 14) of the soybean cyst nematode (SCN). In contrast, the rhg1 locus underlying resistance to Hg Type 0 was found clustered with three loci for resistance to SDS leaf scorch and one for root infection. The aims of this study were to compare the inheritance of resistance to leaf scorch and root infection in a population that segregated for resistance to SCN and to identify the underlying quantitative trait loci (QTL). “Hartwig”, a cultivar partially resistant to SDS leaf scorch, F. virguliforme root infection and SCN HG Type 1.3.6.7 was crossed with the partially susceptible cultivar “Flyer”. Ninety-two F5-derived recombinant inbred lines and 144 markers were used for map development. Four QTL found in earlier studies were confirmed. One contributed resistance to leaf scorch on linkage group (LG) C2 (Satt277; P = 0.004, R 2 = 15%). Two on LG G underlay root infection at R8 (Satt038; P = 0.0001 R 2 = 28.1%; Satt115; P = 0.003, R 2 = 12.9%). The marker Satt038 was linked to rhg1 underlying resistance to SCN Hg Type 0. The fourth QTL was on LG D2 underlying resistance to root infection at R6 (Satt574; P = 0.001, R 2 = 10%). That QTL was in an interval previously associated with resistance to both SDS leaf scorch and SCN Hg Type 1.3.6.7. The QTL showed repulsion linkage with resistance to SCN that may explain the relative susceptibility to SDS of some SCN resistant cultivars. One additional QTL was discovered on LG G underlying resistance to SDS leaf scorch measured by disease index (Satt130; P = 0.003, R 2 = 13%). The loci and markers will provide tagged alleles with which to improve the breeding of cultivars combining resistances to SDS leaf scorch, root infection and SCN HG Type 1.3.6.7.

Supplementary material

122_2008_728_MOESM1_ESM.doc (24 kb)
Supplementary Figure 1: Correlation between leaf scorch measured as mean DX at the R6 and root infection measured as IS at the R8. Among the metrics used to measure leaf and root SDS these two showed the closest correlation. The data was from different years. Only lines with IS scores are shown. The correlation was significant P<0.05 with 49 df (DOC 23 kb)
122_2008_728_MOESM2_ESM.doc (68 kb)
Supplementary Figure 2. Gbrowse representation of the MTP clones in a portion of the soybean genome showing build 4 linkage group G from 1 to 10 Mbp encompassing cqRfs1, cqRfs2, qRfs3 and rhg1 (cqSCN-001) closely linked to Satt309. A 10 Mbp region with loci, QTL, clones, contigs, sequences and gene models was shown. Loci, or genetic map DNA markers, were shown as red arrow heads. QTL in the region were shown as blue bars. BAC clones were shown as the coalesced purple bar. Contigs were shown as green bars. Polyploid region contigs have ctg numbers greater than 8,000. Sequences from MTP BAC ends were shown as black lines. Related gene annotations were shown as purple lines (the 5 most probable Blastx hits at P < e-5 were listed). ESTs mapped to MTP BACs were shown as golden bars and annotated with master plate address and gene model (if known) below the bar and EST name above the bar. Clicking on EST or MTP clones would bring up the gene index number. MTP4 clones were annotated below the bar with MTP and the MTP plate address. MTP2 clones can be identified as they have BES and EST hits shown. BES-SSR markers were shown as green lines below the MTP clones at (http://soybeangenome.siu.edu/cgi-bin/gbrowse/soybeanv4) (DOC 68 kb)
122_2008_728_MOESM3_ESM.doc (126 kb)
Supplementary tables (DOC 125 kb)

Copyright information

© Springer-Verlag 2008