Submitted to: Euphytica
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 6/1/2006
Publication Date: 8/14/2006
Citation: Lu, P., Shannon, G., Sleper, D.A., Nguyer, H.T., Cianzio, S.R., Arelli, P.R. Genetics of cyst nematode resistance in soybean PIs 467312 and 507354.Euphytica, 149(3):259-265.
Interpretive Summary: Soybean yields worldwide are limited by the soybean cyst nematode (SCN), a microscopic-size worm attacking roots of the plant. Resistant cultivars have been the most effective means of controlling the pest. The majority of resistant cultivars trace their resistance to soybean accessions Peking and/or PI 88788. Nematode populations are variable and have adapted to reproduce on resistant cultivars. Soybean plant introductions (PI) 467312 and 507354 are unique sources of resistance. Resistance to the nematode in these two PIs is controlled by three or four genes, depending on the PI and nematode population attacking the plant. This information on the number of genes controlling resistance to the pest will help soybean breeders develop new cultivars with better resistance to the nematode.
Technical Abstract: Soybean [Glycine max (L.) Merr] plant introductions PI 467312 and PI 507354, are unique because they provide resistance to several nematode populations, i.e. SCN HG types 0,2.7, and 184.108.40.206 (corresponding to races 3, 5, and 14) and HG types 2.5.7, 0, and 2.7 (corresponding to races 1, 3, and 5), respectively. The genetic basis of SCN resistance in these PIs is not yet known. We have investigated the inheritance of resistance to SCN HG types 0, 2.7, and 220.127.116.11 (races 3, 5, and 14) in PI 467312 and the SCN resistance to SCN HG types 2.5.7 and 2.7 (races 1 and 5) in PI 507354. PI 467312 was crossed to ‘Marcus’, a susceptible cultivar to generate F1 hybrids, 196 random F2 individuals, and 196 F2:3 families. PI 507354 and the cultivar Hutcheson, susceptible to all known SCN races, were crossed to generate F1 hybrids, 225 random F2 individuals and 225 F2:3 families. The F2:3 families from each cross were evaluated for responses to the specific SCN HG Types in the greenhouse. Chi-square (X2 ) analyses showed resistance from PI 467312 to HG types 2.7, and 18.104.22.168 (races 5 and 14) was conditioned by one dominant and two recessive genes (Rhg, rhg, rhg) and resistance to HG type 0 (race 3) was controlled by three recessive genes (rhg, rhg, rhg). The 225 F2:3 progenies in Pop 507354 showed a segregation of 2:223 (R:S) for response to both HG types 2.5.7 and 2.7 (corresponding to races 1 and 5). The Chi square analysis showed SCN resistance from PI 507354 fit a one dominant and 3 recessive gene model (Rhg, rhg, rhg, rhg). This information will be useful to soybean breeders who use these sources to develop SCN resistant cultivars.