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

Abstract

To develop soybean [Glycine max (L.) Merr.] cultivars resistant to common cutworm (CCW; Spodoptera litura Fabricius), it is important to clarify the effects and genetic characteristics of quantitative trait loci (QTLs) for resistance. In a prior study, we detected two QTLs, named CCW‐1 and CCW‐2, for resistance to CCW in a resistant germplasm, ‘Himeshirazu’. Other researchers detected a major QTL for herbivorous insect resistance in PI 229358. Here we constructed near isogenic lines (NILs) of the QTLs via recurrent backcrossing and evaluated the effect of each QTL on antibiosis resistance to CCW. To confirm allelism between CCW‐1 and the PI 229358‐derived QTL, we did a crossing test. The NILs exhibited significant resistance to CCW compared with the susceptible parent, although the resistance varied 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.

Genetic Study on Resistance to the Common Cutworm and Other Leaf-eating Insects in Soybean

“…The effect of another QTL (around Satt567) in LG-M that has been detected in Himeshirazu and named CCW-2 is also evident (Table 3). Komatsu et al 24 confirmed that this Himeshirazu allele actually suppressed the growth of CCW larvae and the effect equaled that of the other resistance gene in LG-M (around Sat_258). In addition, no interaction was detected between the resistance alleles of the QTL.…”

“…Zhu et al 56 also confirmed the effect of a PI229358 allele, and located the gene between Sat_258 and Satt702, which represents a span of 0.52 cM. Komatsu et al 24 reported 2 . An LOD score of 3.53 was used for the QTL detection threshold based on a Type I error rate of 5%.…”

“…In Japan, a line (Kyushu 155) recently developed by marker-assisted recurrent backcrossing combines the resistance to the CCW and excellent agronomic characteristics 24 . The line inherits two resistance genes from Himeshirazu (Table 3), but the maturity, plant height, number of branches, yield, and seed qualities are similar to those of the recurrent parent Fukuyutaka (data not shown).…”

“…Thus, breeders have hoped to find more efficient selection methods based on the use of DNA markers. Genetic studies of resistance have progressed well [22][23][24] , and elite CCW-resistant lines have been developed by means of marker-assisted selection combined with recurrent backcrossing 24 . The soybean resistance to insects is also important in the United States, where several lepidopteran insects have been recognized as serious pests of soybean 4 .…”

Construction of a BAC Library for a Defoliating Insect-Resistant Soybean and Identification of Candidate Clones Using a Novel Approach

“…Therefore, several efforts have been initiated to better characterize and eventually clone the major gene(s) responsible for insect resistance in soybean. Rector et al (1998Rector et al ( , 2000 used restriction fragmentlength polymorphism markers to identify a major quantitative trait locus (QTL) controlling both antixenosis (negative influence on insect preference and/or feeding) and antibiosis (adverse effects on one or more biological systems of insects) on linkage group M. This QTL, named QTL-M, was confirmed in different soybean backgrounds (Komatsu et al 2008;Walker et al 2004;Zhu et al 2006Zhu et al , 2008. Zhu et al (2006) fine-mapped QTL-M to an approximately 0.5-cM interval flanked by Sat_258 and Satt702 through genotyping and phenotyping recombinant substitution lines identified from advanced backcross progenies.…”