Su Yuan-Chih, Wang Po-Shung, Yang Jhih-Ling, Hong Hong, Lin Tzu-Kai, Tu Yuan-Kai, Kuo Bo-Jein
Department of Agronomy, National Chung Hsing University, No. 145 Xingda Road, South District, Taichung City, 40227, Taiwan (R.O.C.).
Division of Crop Science, Taiwan Agricultural Research Institute, No. 189, Zhongzheng Road, Wufeng District, Taichung City, 41362, Taiwan (R.O.C.).
Bot Stud. 2020 May 20;61(1):17. doi: 10.1186/s40529-020-00294-2.
The cropping area of genetically modified (GM) crops has constantly increased since 1996. However, currently, cultivating GM crops is associated with many concerns. Transgenes are transferred to non-GM crops through pollen-mediated gene flow, which causes environmental problems such as superweeds and introgressive hybridization. Rapeseed (Brassica napus L.), which has many GM varieties, is one of the most crucial oil crops in the world. Hybridization between Brassica species occurs spontaneously. B. rapa grows in fields as a weed and is cultivated as a crop for various purposes. Both B. rapa weeds and crops participate in gene flow among rapeseed. Therefore, gene flow risk and the coexistence of these two species should be studied.
In this study, field experiments were conducted at two sites for 4 years to evaluate gene flow risk. In addition, zero-inflated models were used to address the problem of excess zero values and data overdispersion. The difference in the number of cross-pollination (CP) events was nonsignificant between upwind and downwind plots. The CP rate decreased as the distance increased. The average CP rates at distances of 0.35 and 12.95 m were 2.78% and 0.028%, respectively. In our results, zero-inflated negative binomial models were comprehensively superior to zero-inflated Poisson models. The models predicted isolation distances of approximately 1.36 and 0.43 m for the 0.9% and 3% threshold labeling levels, respectively.
Cultivating GM crops is prohibited in Taiwan; however, the study results can provide a reference for the assessment of gene flow risk and the coexistence of these two species in Asian countries establishing policies for GM crops.
自1996年以来，转基因作物的种植面积不断增加。然而，目前种植转基因作物引发了诸多担忧。转基因通过花粉介导的基因流动转移到非转基因作物中，这会导致诸如超级杂草和渐渗杂交等环境问题。油菜（甘蓝型油菜）有许多转基因品种，是世界上最重要的油料作物之一。芸苔属物种之间会自然发生杂交。白菜型油菜作为杂草生长在田间，并作为多种用途的作物进行种植。白菜型油菜杂草和作物都参与了油菜之间的基因流动。因此，应研究基因流动风险以及这两个物种的共存情况。
在本研究中，在两个地点进行了为期4年的田间试验，以评估基因流动风险。此外，使用零膨胀模型来解决零值过多和数据过度离散的问题。上风处和下风处地块的异花授粉（CP）事件数量差异不显著。CP率随距离增加而降低。在0.35米和12.95米距离处的平均CP率分别为2.78%和0.028%。在我们的结果中，零膨胀负二项式模型总体上优于零膨胀泊松模型。对于0.9%和3%的阈值标签水平，模型预测的隔离距离分别约为1.36米和0.43米。
台湾地区禁止种植转基因作物；然而，研究结果可为亚洲国家制定转基因作物政策时评估基因流动风险以及这两个物种的共存情况提供参考。
