Is yield enhancement by CO_2 enrichment greater in genotypes with a higher capacity for nitrogen fixation?
Is yield enhancement by CO_2 enrichment greater in genotypes with a higher capacity for nitrogen fixation?
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固氮能力较高的基因型中，CO_2 富集对产量的提高是否更大？
DOI：
10.1016/j.agrformet.2011.06.003
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发表时间：
2011
影响因子：
6.2
通讯作者：
M.
中科院分区：
文献类型：
--
作者：
Otera;M.;Kokubun;M.;Tabei;H.;Matsunami;T.;Maekawa;T.;Okada;M.
以前发现，当氮(N)供应充足时，产量对CO2浓度升高的响应性更大；然而，固氮能力的基因型差异是否影响大豆的产量响应性尚不清楚。我们检验了一种假设，即具有更高氮固定能力的基因型大豆对升高[CO2]的产量响应性更强。我们使用了三种具有不同结瘤能力的近等基因型：超结瘤型、正常结瘤型和非结瘤型。植物受到两种[CO2]水平（环境或升高：环境+200μmolmol−1）和两种温度（低或高：低+ca）的影响。4-5°C)，使用温度梯度室。无论CO2和温度如何，超结瘤基因型均表现出较高的叶片氮含量。无论基因型如何，在生长早期，co2富集均可提高光合速率，而在生长后期则无此作用。这种光合驯化反映在所有基因型的生物量生产中。结瘤基因型比非结瘤基因型对升高[CO2]的产量响应更大，但正常结瘤基因型和超结瘤基因型之间的基因型差异不明显，因此我们的假设没有得到充分验证。
Yield responsiveness to elevated CO2concentration [CO2] was previously found to be greater when nitrogen (N) was supplied in adequate amounts; however, it remains unclear whether genotypic differences in N2-fixing capacity affect yield responsiveness in soybean. We tested the hypothesis that yield responsiveness to elevated [CO2] in soybean is greater in a genotype with a higher capacity for N2fixation. We used three near-isogenic genotypes with contrasting nodulation capacities: super-nodulating, normally nodulating and non-nodulating genotypes. Plants were subjected to two levels of [CO2] (ambient or elevated: ambient+200μmolmol−1) and two temperature regimes (low or high: low+ca. 4–5°C) using temperature gradient chambers. The super-nodulating genotype exhibited a higher N content in leaves, regardless of [CO2] and temperature. Photosynthetic rates were enhanced by CO2enrichment at earlier growth stages, but not at later growth stages, regardless of genotype. This photosynthetic acclimation was reflected in biomass production in all the genotypes examined. Yield responsiveness to elevated [CO2] was greater in the nodulating genotypes than in the non-nodulating genotype, but the genotypic differences were obscured between the normally nodulating and super-nodulating genotype, thus our hypothesis was not fully verified.