Reaction of Soybean Cyst Nematode Resistant Plant Introductions to Root-Knot and Reniform Nematodes

Soybean cyst [SCN, Heterodera glycines Ichinohe], southern root-knot [RKN, Meloidogyne incognita (Kofoid and White) Chitwood] and reniform nematodes [RN, Rotylenchlus reniformis (Linford and Oliveria)] are common plant-parasitic nematode species in southern US fields. Each nematode individually or collectively causes significant economic losses to field grown soybean. A subset of 120 soybean plant introductions (PIs) selected from the USDA Soybean Germplasm Collection have been shown to be resistant to one or more SCN populations (HG Types); however, many of these PIs have not been screened for resistance to either RKN or RN. The objective of this research was to evaluate these germplasm accessions for resistance to RKN and RN. The evaluation for RKN resistance was conducted in RKN infested field plantings after potatoes near Charleston, MO in 2006 and 2007. The evaluation for RN resistance was performed in a greenhouse at Fayetteville, AR, in 2007. Out of these accessions, 64 PIs were identified with high or moderate resistance to RKN. Of these 64 lines, 24 accessions showed good resistance to both RKN and RN. These new sources of resistance to multiple nematodes will be valuable materials for soybean breeding programs to develop new resistant cultivars that can overcome yield losses caused by one or more of these nematode species.