Zhu S, Walker D R, Boerma H R, All J N, Parrott W A
Department of Crop and Soil Sciences, University of Georgia, Athens, GA 30602, USA.
Theor Appl Genet. 2008 Feb;116(4):455-63. doi: 10.1007/s00122-007-0682-2. Epub 2007 Dec 7.
The crystal proteins coded by transgenes from Bacillus thuringiensis (Bt) have shown considerable value in providing effective insect resistance in a number of crop species, including soybean, Glycine max (L.) Merr. Additional sources of soybean insect resistance would be desirable to manage the development of tolerance/resistance to crystal proteins by defoliating insects and to sustain the deployment of Bt crops. The objective of this study was to evaluate the effects and interactions of three insect resistance quantitative trait loci (QTLs; QTL-M, QTL-H, and QTL-G) originating from Japanese soybean PI 229358 and a cry1Ac gene in a "Benning" genetic background. A set of 16 BC(6)F(2)-derived near isogenic lines (NILs) was developed using marker-assisted backcrosses and evaluated for resistance to soybean looper [SBL, Pseudoplusia includens (Walker)] and corn earworm [CEW, Helicoverpa zea (Boddie)] in field cage, greenhouse, and detached leaf assays. Both Bt and QTL-M had significantly reduced defoliation by both SBL and CEW and reduced larval weight of CEW. The antibiosis QTL-G had a significant effect on reducing CEW larval weight and also a significant effect on reducing defoliation by SBL and CEW in some assays. The antixenosis QTL-H had no main effect, but it appeared to function through interaction with QTL-M and QTL-G. Adding QTL-H and QTL-G further enhanced the resistance of the Bt and QTL-M combination to CEW in the field cage assay. These results should help guide the development of strategies for effective management of insect pests and for sustainable deployment of Bt genes.
苏云金芽孢杆菌（Bt）转基因编码的晶体蛋白已在包括大豆[Glycine max (L.) Merr.]在内的多种作物中显示出在提供有效抗虫性方面的巨大价值。为了应对食叶昆虫对晶体蛋白耐受性/抗性的发展，并维持Bt作物的种植，需要更多大豆抗虫性来源。本研究的目的是评估源自日本大豆PI 229358的三个抗虫数量性状基因座（QTL；QTL-M、QTL-H和QTL-G）以及“Benning”遗传背景下的cry1Ac基因的效应和相互作用。利用标记辅助回交培育了一组16个BC(6)F(2)衍生的近等基因系（NIL），并在田间网室、温室和离体叶片试验中评估了它们对大豆夜蛾[SBL，Pseudoplusia includens (Walker)]和玉米穗虫[CEW，Helicoverpa zea (Boddie)]的抗性。Bt和QTL-M均显著减少了SBL和CEW造成的落叶，并降低了CEW幼虫的体重。抗生性QTL-G对降低CEW幼虫体重有显著作用，在某些试验中对减少SBL和CEW造成的落叶也有显著作用。忌避性QTL-H没有主要效应，但它似乎通过与QTL-M和QTL-G相互作用发挥作用。在田间网室试验中，添加QTL-H和QTL-G进一步增强了Bt和QTL-M组合对CEW的抗性。这些结果应有助于指导制定有效管理害虫和可持续部署Bt基因的策略。
