Seed Composition of Soybean Grafted Onto SCN Resistant/susceptible Rootstock.
Paul Beuselinck, USDA-ARS Plant Genetics Research Unit, University of Missouri, Plant Sciences Division, Columbia, MO 65211 and Craig Roberts, 108 Waters Hall, University of Missouri, University of Missouri, Dept. of Agronomy, Columbia, MO 65211.
Soybean cyst nematode (SCN, Heterodera glycines Ichinohe) is the most widespread pest of soybean in the USA and worldwide. Soybean yields benefit from utilizing SCN-resistant varieties in fields infested with SCN. The objective of this study was to determine if SCN resistant or susceptible rootstock influenced the composition of the seed of soybean lines differing in unsaturated fatty acids (FA). Five soybean lines were pruned above the cotyledons during early seedling growth to promote development of two axillary branches. Plants were Y-grafted to generate a 5X5 combination of plants with a SCN susceptible or resistant rootstock having a self-grafted branch, a scion (alien) grafted branch, or ungrafted branch. Control plants had an ungrafted branch and a self-grafted branch. The soybean lines used were: 1) S02-1379-2 with high oleic, 2) IA 3017 with low linolenic, 3) Williams 82 with normal FA, 4) SN97-6946 (SCN resistant to all major races) with normal FA (SCNR) and 5) Magellan (SCN susceptible with normal FA (SCNS). Grafted plants were transplanted into field plots near Columbia, MO that were verified to be infested with SCN Race 3. The field was divided into 4 blocks and 2 blocks were randomly chosen and planted with Asgrow line 3302 (SCN susceptible) and the other 2 blocks to 3701 (SCN resistance to Race 3 derived from PI-88788). Grafted plants were randomly transplanted among the Asgrow lines and grown to physiologic maturity (R8) in 2004 and 2005. Seeds were analyzed for individual unsaturated fatty acids and nitrogen. Composition comparisons made between the seed produced from lines grafted on SCN resistant or susceptible rootstock, self-grafts, and ungrafted branches will be presented.