Antibiosis Resistance of QTL Introgressive Soybean Lines to Common Cutworm ( Spodoptera litura Fabricius)

To develop soybean [Glycine max (L) Merr.] cultivars resistant to common cutworm (CCW; Spodptera litura Fabricius, it is important to clarify the effects and gnetic characteristics of quantitative trait loci (QTLs) for resiatane. In a prior study, we detected two OThs, named CCW-1 and CCW2, for resistance to COW in a resistant germplasm, Himeshirazu'. Other researchers detected a major QTL for herbiorous insect resistance in PI 229358. Here we constructed near isogenic lines (NILs) of the QTLs via recurrent beckcrossing and evaluated the effect of each QTL on antibiosis resisnce to CCW. To confirm between CCW-1 and the Pl 229358-derived QTL, we did a crossing test. The NILs exhileted significant resistance to CCW compared with the susceptible parent, afthough the resistance variated between years. The effects of CCW-1 and CCW-2 were similar, and no allelic interaction between them was detected. The crossing test confirmed that CCW-1 and the PI 229358-derived QTL were Identical. But the alleles could be different, because the NILs derived from Himeshirazu and PI 229358 showed different levels of resistance.