Yang Bing, Chen Qunying, Liu Xianghui, Chen Fajun, Liang Yuyong, Qiang Wei, He Lulu, Ge Feng
Key Laboratory of Mountain Ecological Restoration and Bioresource Utilization & Ecological Restoration, Biodiversity Conservation Key Laboratory of Sichuan Province, Chengdu Institute of Biology, Chinese Academy of Sciences, Chengdu, China.
State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing, China.
Front Plant Sci. 2020 Feb 19;11:88. doi: 10.3389/fpls.2020.00088. eCollection 2020.
The wide-scale adoption of transgenic crops has aroused public concern towards potential impacts to the ecological services of soil fauna, such as soil nematodes. However, few studies has examined whether the cultivation of transgenic rice would pose greater threats to soil nematode community and associated ecological functions than insecticides application. Moreover, what are determinants of soil nematode community in paddy fields remains unclear. During a 3-year field study, rhizosphere soil samples of transgenic-Bt rice, its counterpart non-Bt parental rice and not-Bt rice with insecticides application were taken at four times in the rice developmental cycle using a random block design with three replications for each treatment. We hypothesized that the effects of pest management practice on soil nematode abundance and metabolic footprint change with trophic group and sampling time. We also predicted there were significant differences in structure and composition of soil nematode community across the three treatments examined and sampling times. In agreement with our expectation, the effects of pest management practice on nematode abundance and metabolic footprints depend on trophic group and sampling time. However, pest management practice exerted no apparent effect on nematode diversity and community composition. Soil nutrient availability and C:N molar ratio are the primary regulating factor of soil nematode community in rice paddy fields. In conclusion, our findings implied that changes in abundance, diversity, metabolic footprints associated with the crop growth stage overweighed the application of rice and insecticides. The cultivation of rice Huahui-1 exerted no measurable adverse effect on soil nematode community in rhizosphere soil over 3 years of rice cropping.
转基因作物的广泛种植引起了公众对其对土壤动物生态服务（如土壤线虫）潜在影响的关注。然而，很少有研究探讨转基因水稻的种植是否会比施用杀虫剂对土壤线虫群落及相关生态功能构成更大威胁。此外，稻田土壤线虫群落的决定因素仍不清楚。在一项为期3年的田间研究中，采用随机区组设计，对转基因Bt水稻、其对应的非Bt亲本水稻以及施用杀虫剂的非Bt水稻在水稻生长周期的四个阶段采集根际土壤样本，每个处理设置三个重复。我们假设害虫管理措施对土壤线虫丰度和代谢足迹的影响会随着营养类群和采样时间而变化。我们还预测，在所研究的三种处理和采样时间下，土壤线虫群落的结构和组成存在显著差异。与我们的预期一致，害虫管理措施对线虫丰度和代谢足迹的影响取决于营养类群和采样时间。然而，害虫管理措施对线虫多样性和群落组成没有明显影响。土壤养分有效性和碳氮摩尔比是稻田土壤线虫群落的主要调节因素。总之，我们的研究结果表明，与作物生长阶段相关的线虫丰度、多样性和代谢足迹的变化超过了水稻和杀虫剂的施用影响。在三年的水稻种植过程中，华恢1号水稻的种植对根际土壤中的土壤线虫群落没有产生可测量的不利影响。
