Contamination and management of resistance evolution to high-dose transgenic insecticidal crops
Contamination and management of resistance evolution to high-dose transgenic insecticidal crops
复制标题
DOI：
10.1007/s12080-010-0109-6
复制
发表时间：
2012-05-01
影响因子：
1.6
通讯作者：
Andow, David A.
中科院分区：
文献类型：
--
作者：
Glaum, Paul R.;Ives, Anthony R.;Andow, David A.
就玉米和棉花而言，一些国家目前正在种植表达苏云金芽孢杆菌毒素的转基因品种。为了减缓抗性演变，广泛实施“高剂量/避难所”战略，其中抗性是隐性的，一些田地（或田地中的区域）专门种植Bt作物，而其他田地专门种植非转基因的易感昆虫避难所作物。然而，这一战略可能会受到污染的破坏。在这里，我们调查的一般模型的抗性演变的高剂量事件中，由于无意中混合的种子，志愿者植物，或花粉流之间的Bt和非Bt品种，再加上种子保存的农民被污染的领域。Bt植物对避难所的污染增加了抗性选择，从而加速了抗性进化。然而，在大多数情况下，这种影响很小。非转基因植物对Bt田地的污染可能会产生相反的效果，并总是降低抗性进化的速度。虽然情况往往如此，但并非总是如此。如果幼虫在田间的植物之间移动，那么高的移动速率可能会逆转Bt田间污染的影响，从而减缓抗性进化。此外，如果Bt和避难所领域之间的成年女性的扩散率低，那么Bt领域的污染可能会加速阻力。这些结果表明，污染有可能破坏高剂量/避难所战略的效力，但根据具体的害虫和情况，污染可能不是一个问题。
For maize and cotton, transgenic varieties that express toxins derived from Bacillus thuriengensis (Bt) are now planted in several countries. To slow resistance evolution, the "high-dose/refuge" strategy is broadly implemented in which resistance is recessive and some fields (or areas within fields) are planted exclusively with Bt crops and other fields planted exclusively with non-transgenic refuge crops for susceptible insects. This strategy, however, could potentially be undermined by contamination. Here, we investigate general models of resistance evolution for high-dose events in which fields are contaminated due to the inadvertent mixing of seeds, volunteer plants, or pollen flow between Bt and non-Bt varieties coupled with seed-saving by farmers. Contamination of the refuge by Bt plants increases selection for resistance, thereby speeding resistance evolution. Nonetheless, in most situations this effect is small. Contamination of Bt fields by non-transgenic plants might be expected to have the opposite effect and always reduce the rate of resistance evolution. While this is often the case, it is not always so. If larvae move among plants within a field, then high movement rates may reverse the effect of contamination of Bt fields to slow resistance evolution. Furthermore, if the dispersal rates of adult females between Bt and refuge fields are low, then contamination of Bt fields may speed resistance. These results suggest that contamination has the potential to undermine the efficacy of the high-dose/refuge strategy, yet depending upon the particular pest and situation, contamination may not be a concern.