Bt Pollen Dispersal and Bt Kernel Mosaics: Integrity of Non-Bt Refugia for Lepidopteran Resistance Management in Maize
Bt Pollen Dispersal and Bt Kernel Mosaics: Integrity of Non-Bt Refugia for Lepidopteran Resistance Management in Maize
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DOI：
10.1603/ec12128
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发表时间：
2012-10-01
影响因子：
2.2
通讯作者：
Hutchison, W. D.
中科院分区：
文献类型：
--
作者：
Burkness, Eric C.;Hutchison, W. D.
田间试验于2009年和2010年在明尼苏达州的罗斯蒙特进行，以测量从Bt玉米到相邻的非Bt避难所玉米块的花粉移动。随着Bt玉米杂交种在美国的使用不断增加，以及新的昆虫抗性管理（昆虫抗性管理）计划的实施，有必要衡量这些昆虫抗性管理计划的有效性。在明尼苏达州，玉米的主要鳞翅目害虫包括欧洲玉米螟Ostrinia nubilalis（Hubner）和玉米穗虫Helicoverpa zea（Boddie）。转基因玉米中的主要计划是使用表达高剂量杀虫蛋白的杂交种和含有不表达杀虫蛋白的杂交种的昆虫避难所，所述杂交种产生易感昆虫。风助花粉在玉米中的移动容易发生，并且是玉米授粉的主要方法。花粉运动和生活力的结合决定了避难玉米异花授粉的潜力。在2009年和2010年，异花授粉发生的频率最高的北部和东部的Bt玉米田，但在所有方向上都发现了一定的水平。最高水平的异花授粉（75%），发现在前四行（3米）的非Bt玉米相邻的Bt玉米，并在一般情况下，降低水平的异花授粉，发现非Bt玉米种植的Bt玉米。镶嵌的Bt异花授粉的内核被发现在整个耳朵，但在这两年的穗尖有最高的比例异花授粉的内核，这种模式可能与同步的花粉脱落和吐丝之间的Bt和非Bt玉米杂交种。这两年的主导风向都是西北偏西。然而，在这两年，也有来自SSW和WSW的盛行风。需要进一步的研究来量化异花授粉的籽粒中的Bt水平，测量这种籽粒的Bt剂量和相关的鳞翅目害虫存活率，并测量Bt花粉对鳞翅目害虫的影响，特别是当考虑到种子混合物避难所配置时。
Field trials were conducted at Rosemount, MN in 2009 and 2010, to measure pollen movement from Bt corn to adjacent blocks of non-Bt refuge corn. As the use of Bt corn hybrids continues to increase in the United States, and new insect resistance management (IRM) plans are implemented, it is necessary to measure the efficacy of these IRM plans. In Minnesota, the primary lepidopteran pests of corn include the European corn borer, Ostrinia nubilalis (Hubner) and corn earworm, Helicoverpa zea (Boddie). The primary IRM plan in transgenic corn is the use of hybrids expressing a high dose of insecticidal proteins and an insect refuge containing hybrids not expressing insecticidal proteins that produce susceptible insects. Wind-assisted pollen movement in corn occurs readily, and is the primary method of pollination for corn. The combination of pollen movement and viability determines the potential for cross pollination of refuge corn. In 2009 and 2010, cross pollination occurred with the highest frequency on the north and east sides of Bt corn fields, but was found at some level in all directions. Highest levels of cross pollination (75%) were found within the first four rows (3 m) of non-Bt corn adjacent to Bt corn, and in general decreasing levels of cross pollination were found the further the non-Bt corn was planted from the Bt corn. A mosaic of Bt cross-pollinated kernels was found throughout the ear, but in both years the ear tip had the highest percentage of cross-pollinated kernels; this pattern may be linked to the synchrony of pollen shed and silking between Bt and non-Bt corn hybrids. The dominant wind direction in both years was from WNW. However, in both years, there were also prevailing winds from SSW and WSW. Further studies are needed to quantify Bt levels in cross-pollinated kernels, measure the Bt dose of such kernels and associated lepidopteran pest survival, and measure the impact of Bt pollen on lepidopteran pests, particularly when considering the seed mixture refuge configuration.