방풍 구조물 설치에 따른 옥수수 화분 비산 및 교차수분 저감 효과 연구

Study of the effect of windbreaks on reducing maize pollen dispersal and cross-pollination

Pollen-mediated gene flow from genetically modified (GM) maize remains a critical biosafety concern in environmental release trials, especially under open-field conditions. In this study, we investigated the spatial dynamics of cross-pollination and assessed the effectiveness of windbreak structures in mitigating pollen dispersal of maize. From 2022 to 2024, we conducted field trials using the xenia effect to detect cross-pollination between black-kernelled pollen parent and white-kernelled seed parent in maize. Additionally, we examined two types of windbreak structures —a full enclosure and a partial (roofless) barrier—across three growing seasons under variable meteorological conditions. Cross-pollination rates were analyzed in terms of distance from the pollen source, wind direction, wind speed, rainfall, and humidity. In the absence of windbreaks, cross-pollination rates exceeded 30% within 20 m and remained above 3% beyond 90 m under favorable wind conditions. Under these unprotected conditions, a maximum distance of 276 m was required to remain below the 0.1% outcrossing thresholds. After installing full enclosures and roofless barriers, these thresholds were reduced to 118 m and 246 m, respectively, demonstrating that physical barriers can significantly limit gene flow. Based on these results, we recommend that windbreak structures be mandatorily installed when cultivating GM maize. Furthermore, a minimum isolation distance of 250 m should be maintained to prevent pollen-mediated gene flow. This study provides practical data to inform biosafety regulations, support environmental risk assessment, and guide the design of field trials for GM maize under diverse climatic conditions.