Wild bee abundance and seed production in conventional, organic, and genetically modified canola
Wild bee abundance and seed production in conventional, organic, and genetically modified canola
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DOI：
10.1890/03-5271
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发表时间：
2005-06-01
影响因子：
5
通讯作者：
Winston, ML
中科院分区：
文献类型：
--
作者：
Morandin, LA;Winston, ML
农业的生态影响令人担忧，特别是转基因和其他集约化的现代耕作系统，但人们对对野生蜜蜂种群的影响以及随后对授粉的影响知之甚少。 2002 年夏天，我们在加拿大阿尔伯塔省北部的有机、常规和抗除草剂转基因 (GM) 油菜田（甘蓝型油菜和白菜油）中测量了授粉不足（潜在授粉与实际授粉之间的差异）和蜜蜂丰度。蜜蜂丰度数据是使用盘式陷阱和标准化扫网收集的，并通过比较开放授粉和补充授粉花朵的每个果实的种子数量来评估授粉不足。有机田没有授粉赤字，传统田地有中度授粉赤字，转基因田的授粉赤字最大。有机田中的蜜蜂丰度最高，其次是常规田，转基因田中最低。总体而言，采样地点的蜜蜂丰度与授粉缺陷减少之间存在很强的正相关关系。欧洲油菜的结籽量随着蜜蜂数量的增加而增加。由于白菜油是专性异交物种，因此有机田（白菜油菜）中缺乏授粉缺陷可能是由于蜜蜂丰度较高，而不是白菜油菜对传粉媒介的依赖程度低于油菜籽。我们的研究说明了野生蜜蜂对农业生产的重要性，并表明一些农业生态系统可以更好地维持野生蜜蜂的丰富度，从而提高种子产量。进一步研究为什么某些种植系统（例如转基因、抗除草剂油菜籽）的野生蜂丰度较低，将有助于农业生态系统管理，促进粮食生产的可持续性。
The ecological impacts of agriculture are of concern, especially with genetically modified and other intensive, modern cropping systems, yet little is known about effects on wild bee populations and subsequent implications for pollination. Pollination deficit (the difference between potential and actual pollination) and bee abundance were measured in organic, conventional, and herbicide-resistant, genetically modified (GM) canola fields (Brassica napus and B. rapa) in northern Alberta, Canada, in the summer of 2002. Bee abundance data were collected using pan traps and standardized sweep netting, and pollination deficit was assessed by comparing the number of seeds per fruit from open-pollinated and supplementally pollinated flowers. There was no pollination deficit in organic fields, a moderate pollination deficit in conventional fields, and the greatest pollination deficit in GM fields. Bee abundance was greatest in organic fields, followed by conventional fields, and lowest in GM fields. Overall, there was a strong, positive relationship between bee abundance at sampling locations and reduced pollination deficits. Seed set in B. napus increased with greater bee abundance. Because B. rapa is an obligate outcrossing species, the lack of pollination deficit in the organic (B. rapa) fields likely was due to the high bee abundance rather than a lower dependence of B. rapa on pollinators than B. napus canola. Our study illustrates the importance of wild bees to agricultural production and suggests that some agroecosystems may better sustain wild bee abundance, resulting in greater seed production. Further research on why some cropping systems, such as genetically modified, herbicide-resistant canola, have low wild bee abundance would be useful for management of agroecosystems to promote sustainability of food production.