Weedy adaptation in Setaria spp. v. effects of gaseous environment on giant foxtail (Setaria faberii) (poaceae) seed germination
Weedy adaptation in Setaria spp. v. effects of gaseous environment on giant foxtail (Setaria faberii) (poaceae) seed germination
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DOI：
10.3732/ajb.89.3.410
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发表时间：
2002-03-01
影响因子：
3
通讯作者：
Hargrove, M
中科院分区：
文献类型：
--
作者：
Dekker, J;Hargrove, M
研究了自然产生的气体（氧气、氮气、一氧化碳）在有利的温度和湿度条件下对休眠巨狐尾草（Setaria faberia）种子萌发的影响。对气体混合物的发芽反应支持这样的假设，即随着时间的推移，狗尾草种子的发芽行为受到水合种子吸收的氧气量的调节。狗尾草种子的发芽明显受到高于和低于空气浓度 (20% O-2) 的 O-2 浓度（在 N-2 中）的影响：发芽率的最大增加（从 37% 到 60%）发生在 20-25% O-2 之间；在 0-10% O-2 之间，发芽率从 0-30% 增加，令人惊讶的是，10% 和 20% O-2 下的发芽率相似。这些观察结果揭示了对高于和低于农业土壤中常见的 O-2 增量变化的不对称响应。一氧化碳对空气中的 S. faberii 发芽具有相反的影响，具体取决于浓度、刺激和抑制：添加 1% CO 时，发芽率从 37% 增加到 56%，但添加 75% CO 时，发芽率从 37% 下降到 14%。一种解释可能是 CO 存在两种独立的影响，每种影响同时发生在休眠种子的不同生理系统中。空气中高浓度 (75%) CO 抑制种子 发芽，可能是通过抑制线粒体呼吸来实现的。但空气中的低 CO 浓度（01 或 1%）会刺激种子发芽。CO 和 O-2 的哪个生理系统受到影响尚不清楚。 CO 刺激的发芽似乎不太可能是由于对呼吸器官的影响而引起的，但可能是 CO 与种子中未知的生理因素相互作用的结果。我们提供了狗尾草属的模型。休眠与其种子形态、气体发芽数据以及可能参与二氧化碳刺激发芽的假设的第二生理因素一致。
The effects that naturally occurring gases (oxygen, nitrogen, carbon monoxide) may cause in dormant giant foxtail (Setaria faberia) seed germination under favorable temperature and moisture conditions were investigated. The germination responses to gas mixtures supported the hypothesis that S. faberu germination behavior is regulated by the amount of oxygen taken into hydrated seed over time Setaria faberu seed germination was markedly affected by O-2 concentration (in N-2) above and below that of air (20% O-2): the largest increase in germination (from 37 to 60%) occurred between 20-25% O-2; between 0-10% O-2, germination increased from 0-30%, and surprisingly germination at 10 and 20% O-2 was similar. These observations reveal an asymmetrical response to incremental changes in O-2 above and below that typically found in agricultural soils. Carbon monoxide had opposite effects on S. faberii germination in air depending on concentration, stimulation, and inhibition: germination increased from 37 to 56% with the addition of 1% CO, but decreased from 37 to 14% with 75% added CO. An explanation may be that there are two separate effects of CO, each occurring in different physiological systems of dormant seeds at the same time At high concentrations (75%) in air CO inhibited seed germination, probably by inhibiting mitochondrial respiration. But low CO concentrations (01 or 1%) in air stimulated seed germination It was not apparent which physiological system(s) CO and O-2, affected. It seems unlikely that CO-stimulated germination arises from effects on the respiratory apparatus, but may be a consequence of CO interactions with an as yet unknown physiological factor in the seed. We provide a model of Setaria spp. dormancy consistent with its seed morphology, the gas-germination data, and the hypothesized second physiological factor that may be involved in CO stimulated germination.