ABSTRACT

Future agricultural management programs should consider the responsiveness of crops to increasing atmospheric CO₂ concentrations ([CO₂]) and temperatures. Eddo is an important tuber crop widely grown in Asia, but its response to [CO₂] and temperatures remains largely unknown. We investigated the responses of eddo and rice plants to elevated [CO₂] (ambient [CO₂] + 200 µmol mol⁻¹) at low and high temperatures during the early-to-intermediate growth stage in temperature gradient chambers in 2018 and 2019. The dry weights (DWs) of the eddo leaf blades, petioles, roots, and above-ground parts as well as the DWs of the rice leaf blades, leaf sheaths and stems, above-ground parts, and whole plants significantly increased under elevated [CO₂]. The number of leaves, leaf area, and SPAD value of eddo significantly increased under elevated [CO₂], whereas the leaf area and SPAD value of rice did not. The net photosynthetic rate of eddo and rice tended to increase under elevated [CO₂]. The increasing ratio of the total DW in elevated vs ambient [CO₂] was significantly higher for eddo than for rice. The result indicates that elevated [CO₂] increases the eddo biomass more than the rice biomass, possibly because of the increasing eddo leaf area and SPAD value induced by elevated [CO₂]. The total DW of rice increased significantly in response to the high air temperature under elevated [CO₂] conditions. However, the effect of [CO₂] on the total DW of eddo was similar at both temperatures, reflecting the non-significant interaction between [CO₂] and temperature.

摘要

未来的农业管理计划应考虑农作物对大气CO ₂浓度（[CO ₂ ]）和温度升高的响应能力。Eddo是亚洲广泛种植的重要块茎作物，但其对[CO ₂ ]和温度的反应仍然未知。我们调查了eddo和水稻植物对[CO ₂ ]升高（环境[CO ₂ ] + 200 µmol mol ^-1）在2018年和2019年的温度梯度试验箱中处于早期和中期生长阶段的高温和低温下。eddo叶片，叶柄，根，地上部分以及DW的干重（DW）在[CO ₂ ]升高的情况下，水稻叶片，叶鞘和茎，地上部分以及整个植物的数量显着增加。在[CO ₂ ]升高的情况下，eddo的叶数，叶面积和SPAD值显着增加，而水稻的叶面积和SPAD值则没有。在[CO ₂ ]升高的情况下，江户和水稻的净光合速率趋于增加。相对于环境[CO _2]，总DW的增加比率eddo的Ed显着高于大米。结果表明，升高的[CO ₂ ]比水稻的生物量增加了eddo生物量，这可能是由于升高的[CO ₂ ]引起的eddo叶面积和SPAD值的增加。在升高的[CO ₂ ]条件下，稻米的总DW显着增加，以应对较高的气温。但是，[CO ₂ ]对eddo的总DW的影响在两个温度下都相似，反映了[CO ₂ ]与温度之间没有显着的相互作用。