Identification of a new major QTL associated with resistance to soybean cyst nematode (Heterodera glycines)

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

“…The number of QTL was less than the three found in PxD (Njiti et al 2002) and the eight found in ExF Farias-Neto et al 2007). The locus on D2 was in the same interval as a locus for resistance to Hg Type 1.3.6.7 from PI88788 (Schuster et al, 2001); Pyramid ; and PI437654 (Webb et al 1995).…”

“…Consequently, repulsion linkage and/or pleiotropy is expected with loci underlying resistance to SDS at loci that underlie resistance to Hg Type 1.3.6.7 (Webb et al 1995;Schuster et al 2001;Concibido et al 2004). …”

Validation of microsatellite markers for assisted selection of soybean resistance to cyst nematode races 3 and 14

“…One QTL with greater effect (R 2 = 58.4%) was detected in Satt309 -Sat_168 interval (Table 2), that is, in the same region where a QTL was found for resistance to race 3 in the previous population, close to the locus of rhg1 resistance gene (Cregan et al, 1999). The QTL associated to race 14, reported by Schuster et al (2001), was not confirmed on D2 linkage group, but polymorphic markers were not identified in the region studied by these authors, in this population. This fact illustrates that the use of markers in breeding depends on their being polymorphic in different populations, because there are no warranty that the markers identified in one population are polymorphic in different populations.…”

“…These two loci account for almost all the variability in soybean for resistance to SCN race 3 (Weisemann et al, 1992;Webb et al, 1995) and a great part of the variability for the other races (Concibido et al, 1997(Concibido et al, , 2004Wang et al, 2004;Guo et al, 2005Guo et al, , 2006. Schuster et al (2001) detected another region with large effect on LG D2 conferring resistance to race 14. It is suggested that the minor genes reported in other LG may be involved in race specificity, but they need to be validated.…”

New Approaches to Selecting Resistance or Tolerance to SDS and Fusarium Root Rot

“…Consequently, repulsion linkage and/or pleiotropy is expected with loci underlying resistance to SDS at loci that underlie resistance to Hg Type 1.3.6.7 (Webb et al, 1995;Schuster et al, 2001;Concibido et al, 2004).…”