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花粉是玉米基因飘逸的重要载体。研究了花粉活力的持续时间和有效控制基因飘逸的隔离距离。在花药刚开裂时采集花粉,置于薄膜层上,放在室外自然条件下保存,每隔一定时间对采集的花粉进行目测和授粉,通过对花粉的目测评判和计算结实率评估花粉活力。试验花粉源区域4000m2,在其周围不同距离的地方种植若干玉米小区,每个小区面积为12.8m2,以测定隔离距离的有效性。作为花粉源的玉米材料包含可用于测定花粉飘逸的叶色标记或种子标记。由于大气压不同,花粉可在花药开裂后1～2小时内保持活力。假定花粉以当地下午平均最大风速直线传播,并可在2小时内保持花粉活力,且忽略花粉沉降率因素,理论上讲,具有活力的花粉可以传播的最大距离为32km。试验结果是在离花粉源100m发生了一定数量的异花授粉,离花粉源200m处有个别异花授粉发生,离花粉源300m处没有异花授粉发生。试验结果与玉米花粉不耐干燥并具高沉降速率的结论一致。试验结果表明距离隔离是控制玉米因授粉而发生基因飘逸的有效方法。
Pollen is an important vector of corn genetics. The duration of pollen activity and the elegant isolation distance that effectively controls the gene are studied. Pollen was harvested just after the anther had cracked. The pollen was collected on the film layer and stored in the natural environment. Visual inspection and pollination of collected pollen were carried out at regular intervals. Pollen viability was evaluated by visual evaluation of pollen and calculation of seed setting rate. 4000m2 of pollen source area was tested and several maize plots were planted at different distances around each area with an area of 12.8m2 to measure the effectiveness of isolation distance. Corn material as a source of pollen contains leaf color markers or seed markers that can be used to determine pollen flow. Due to the different atmospheric pressure, pollen can remain viable within 1-2 hours after anther cleavage. Assuming that the pollen spreads linearly with the average afternoon local maximum wind speed and maintains pollen viability within 2 hours and ignores the pollen deposition rate, in theory, the maximum distance that viable pollen can propagate is 32 km. The results showed that a number of cross-pollination occurred at a distance of 100m from the pollen source. Some cross-pollination occurred at 200m away from the pollen source and no cross-pollination occurred at 300m from the pollen source. The experimental results are consistent with the conclusion that corn pollen is not resistant to drying and has a high sedimentation rate. The experimental results show that distance isolation is an effective method to control gene flow of maize due to pollination.