Kawashima Shigeto, Matsuo Kazuhito, Du Mingyuan, Takahashi Yuichi, Inoue Satoshi, Yonemura Seiichiro
National Institute for Agro-Environmental Sciences 3-1-3 Kannondai, Tsukuba 305-8604, Japan.
Environ Biosafety Res. 2004 Oct-Dec;3(4):197-207. doi: 10.1051/ebr:2005003.
The safety and impact on the environment of transgenic crops are important issues, and studies have shown that pollen from transgenic Bt (Bacillus thuringiensis) corn (Zea mays L.) may kill nontarget insects. To develop an algorithm for assessing the environmental effect of transgenic crops, we arranged a field experiment in Tsukuba, Japan. Pollen dispersal and deposition were measured inside and outside a cornfield throughout the flowering period. Weather conditions such as wind speed and direction were measured at the same time. Pollen dispersal peaked 1 week after the start of flowering and continued for 12 days thereafter. The variation in daily pollen dispersal was similar at all observation points. Both pollen dispersal and deposition decreased exponentially with distance from the cornfield on all days. We estimated potential pollen deposition with a quasi-mechanistic model that incorporates the effects of wind direction, wind speed, and flowering intensity. The daily potential deposition was summed over the flowering period, and then the relationship between distance from the cornfield and the integrated potential deposition was estimated. It was possible to show the effective area of the environmental risk zone posed by genetically modified pollen by combining the distance/deposition relationship with the dose/response relationship derived from a laboratory assay. The algorithm described here can be applied to various wind-pollinated plants to estimate both potential and integrated pollen deposition.
转基因作物的安全性及其对环境的影响是重要问题，且研究表明转基因Bt（苏云金芽孢杆菌）玉米（Zea mays L.）的花粉可能会杀死非靶标昆虫。为开发一种评估转基因作物环境影响的算法，我们在日本筑波安排了一项田间试验。在整个花期测量了玉米田内外的花粉扩散和沉降情况。同时测量了风速和风向等气象条件。花粉扩散在开花开始后1周达到峰值，此后持续12天。所有观测点每日花粉扩散的变化情况相似。在所有日子里，花粉扩散和沉降均随离玉米田距离的增加呈指数下降。我们用一个包含风向、风速和开花强度影响的准机械模型估算了潜在花粉沉降。在花期对每日潜在沉降进行累加，然后估算离玉米田距离与累积潜在沉降之间的关系。通过将距离/沉降关系与实验室分析得出的剂量/反应关系相结合，有可能展示转基因花粉造成的环境风险区的有效范围。这里描述的算法可应用于各种风媒植物，以估算潜在和累积花粉沉降。
