We reported a new white soybean cyst nematode, Heterodera sojae in 2016. This species is closely related to H. glycineswhich has the same host plant. Morphological observations of the cyst, female, male and second-stage juveniles indicatedthat this species is differed from those of H. glycines. Cysts of H. sojae appeared more round, shining and darker thanthat of H. glycines. The distribution of this new cyst nematode in soybean field in Korea is unknown yet. In 2016, 270soil samples were collected from soybean fields and examined the existence of H. glycines and H. sojae. Total of 111samples (41.1%) contained cysts. Among them 77% were H. glycines and 23% were H. sojae. Our results suggest thatextensive researches are required for white soybean cyst nematode.

Plant-parasitic nematodes causes yield losses of more than $100 million per year in the world. Among them, soybeancyst nematode (Heterodera glycines Ichinohe) causes the greatest yield loss to soybean compared to any other pest worldwide.SCN causes yield reductions by feeding on plant nutrients, retarding root growth and inhibiting Bradyrhizobium japonicum(Kirchner) Buchanan nodulation. The primary methods for controlling SCN include planting resistant cultivars and rotationwith nonhost crop. In order to control SCN, we should be breeding resistant soybean cultivars which has resistant genefor this pest. The research that can minimize the damage of the soybean yield is still insufficient, comprehensive andsystematic research is urgently required. Current researches in our lab are discussed.

To select resistant oil seed crops against two species of root-knot nematodes, M. incognita and M. arenaria, 10 cultivars of sesame (Sesamum indicum) and 10 cultivars of perilla (Perilla frutescens var. japonica) were screened in greenhouse pot test. All sesame cultivars tested were resistant to M. incognita but susceptible to M. arenaria. While, perilla was resistant to both Meloidogyne species. Therefore, perilla cultivars could be used as rotation crops in greenhouses infested with both M. incognita and M. arenaria. But, sesame cultivars only can be used as a rotation crops in greenhouses infested with M. incognita but not for M. arenaria.