Li Pu-Fang, Ma Bao-Luo, Yan Weikai, Cheng Zheng-Guo, Li Feng-Min, Xiong You-Cai
Key Laboratory of Grassland Agro-ecosystems, Institute of Arid Agroecology, School of Life Sciences, Lanzhou University, Lanzhou 730000, China.
Agriculture and Agri-Food Canada, Science and Technology Branch, Eastern Cereal and Oilseed Research Centre, 960 Carling Avenue, Ottawa, Ontario, Canada K1A 0C6.
J Sci Food Agric. 2016 Mar 30;96(5):1431-9. doi: 10.1002/jsfa.7237. Epub 2015 May 21.
The hypothesis that positive and negative interactions account for adaptive strategies was tested in a controlled study with two oat (Avena sativa) genotypes: 'Manotick' with erect leaves and 'Oa1316-1' with prostrate leaves. An increasing competition pattern was designed by varying the number of seeds planted in each container and the space between containers, thus creating different planting density regimes (i.e. alternative and solid treatments).
Total biomass of individual plants tended to decrease exponentially with increasing density in both genotypes. Under high density stress, Manotick allocated more biomass to the roots and produced 50% more tillers, leading to more non-productive tillers and lower harvest index in the alternative than in the solid treatment. In contrast, Oa1316-1 allocated more biomass to panicles and stems, and less to the roots, with fewer tillers.
With increasing density and strengthening intraspecific competition, Manotick reduced aboveground biomass allocation, leading to lower yield, while Oa1316-1 decreased allocation to the roots, but increased allocation to the panicles under an increasingly competitive environment. These adjustments were mechanically derived from negative and positive interactions, ensuring greater yield in the prostrate type. Our findings provided a novel rationale for a planting strategy based on plant type selections.
在一项对照研究中，以两种燕麦（ Avena sativa ）基因型进行了关于正负相互作用构成适应性策略这一假设的测试：叶片直立的‘马诺蒂克’和叶片匍匐的‘Oa1316 - 1’。通过改变每个容器中种植的种子数量以及容器之间的间距设计了一种竞争加剧的模式，从而创建了不同的种植密度方案（即交替种植和密植处理）。
两种基因型中，单株植物的总生物量均倾向于随着密度增加呈指数下降。在高密度胁迫下，‘马诺蒂克’将更多生物量分配到根部，并产生多50%的分蘖，导致交替种植处理中产生更多无效分蘖且收获指数低于密植处理。相比之下，‘Oa1316 - 1’将更多生物量分配到穗部和茎部，而分配到根部的较少，分蘖也较少。
随着密度增加和种内竞争加剧，‘马诺蒂克’减少地上生物量分配，导致产量降低，而‘Oa1316 - 1’在竞争日益激烈的环境下减少对根部的分配，但增加对穗部的分配。这些调整机械地源于正负相互作用，确保匍匐型燕麦有更高产量。我们的研究结果为基于植物类型选择的种植策略提供了新的理论依据。
