| Title: | The 'PI 438489B' by 'Hamilton' SNP-based Genetic Linkage Map of Soybean [Glycine max (L.) Merr.] Identified Quantitative Trait Loci that Underlie Seedling SDS Resistance |
| Authors: | Abdelmajid, K., Ramos, L., Leandro, L., Mbofung, G., Hyten, D., Kantartzi, S., Grier, R., Njiti, V., Cianzio, S., Meksem, K. |
| Source: | J. Pl. Geno. Sci. 2012, 1(1):18-30 |
| Abstract: | Soybeans [Glycine max (L.) Merr.] are susceptible to manydiseases including fungal diseases such as soybean suddendeath syndrome (SDS). Several studies reported SDS resistancequantitative trait loci (QTL) on the soybean genomeusing different recombinant inbred line (RIL) populationsand low density genetic linkage maps. High density exclusivelysingle nucleotide polymorphisms-based (SNP-based)maps were not yet reported in soybean. The objectives ofthis study were (1) to construct a high density SNP-basedgenetic linkage map of soybean using the ?PI438489B? by?Hamilton? (PIxH, n=50) recombinant inbred line population,and (2) to map QTL for SDS resistance using this high-densityreliable genetic SNP-based map. The PI438489B by Hamiltonhigh-density SNP-based genetic map was a high density mapcomposed of 31 LGs, 648 SNPs, and covered 1,524.7 cM withan average of 2.37 cM between two adjacent SNP markers.Fourteen significant QTL were identified for SDS resistanceusing interval mapping (IM) and composite interval mapping(CIM) with LOD scores that ranged between 2.6 and 5.0.Twelve QTL were identified for foliar disease severity (FDS)and three QTL for root rot severity (RRS) of which one QTLunderlain both FDS and RRS. The fourteen QTL were mappedonto ten separate chromosomes of the soybean genome. Sevenof the intervals encompassing the QTL had been identifiedpreviously (on LGs C1, C2, D1b, G, L, N and O) associatedwith resistance to SDS but seven were novel (LGs A2 (2), B1,C2, D1a, D1b and O). We constructed the first PI438489B byHamilton exclusively SNP-Based map and identified fourteenQTL that underlie SDS resistance including both resistancesto foliar and root rot symptoms caused by Fusarium virguliformeinfection. The QTL discovered here for SDS resistancecould be useful to include in breeding programs in developingsoybean cultivars resistant to SDS. |