Physiological Traits Contributing to Differential Canopy Wilting in Soybean under Drought
Physiological Traits Contributing to Differential Canopy Wilting in Soybean under Drought
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DOI：
10.2135/cropsci2011.05.0278
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发表时间：
2012-01-01
期刊：
影响因子：
2.3
通讯作者：
King, C. Andy
中科院分区：
文献类型：
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作者：
Ries, Landon L.;Purcell, Larry C.;King, C. Andy
在一些罕见的大豆[Glycine max（L.）梅尔。]基因型，但原因和重要性，这一特点赋予农艺耐旱性知之甚少。我们假设，大豆基因型延迟萎蔫保护土壤水分通过限制蒸腾，这将反映在降低辐射利用效率（芸香）和/或提高水分利用效率（WUE）。在土壤湿度充足时保存的水在干旱通常更严重的季节后期可以使用。在8个环境中的灌溉田间试验比较了已知在干旱期间枯萎的不同基因型的芸香。此外，我们还测量了气孔导度，碳同位素识别（CID），体积土壤水分含量，气孔密度，冠层温度下降。在八个环境中的六个，慢萎蔫基因型一般有较低的芸香比快萎蔫基因型，这是符合我们的假设。4个慢萎蔫基因型中有3个在灌水前土壤含水量高于快萎蔫基因型，这也与假设一致。CID（WUE的代表）存在基因型差异，但与缓慢萎蔫并不一致。气孔导度和冠层温度没有基因型差异。这些结果表明，涉及芸香和水分利用效率的多种机制可能导致这些不同的基因型的水土保持。
Delayed wilting is observed in a few unusual soybean [Glycine max (L.) Merr.] genotypes, but the reasons and importance of this trait for conferring agronomic drought tolerance are poorly understood. We hypothesized that soybean genotypes with delayed wilting conserve soil moisture by restricting transpiration and that this would be reflected in decreased radiation use efficiency (RUE) and/or improved water use efficiency (WUE). Water conserved when soil moisture was plentiful would be available later in the season when drought is usually more severe. Irrigated field experiments in eight environments compared RUE of genotypes known to wilt differently during drought. In addition, we measured stomatal conductance, carbon isotope discrimination (CID), volumetric soil-moisture content, stomatal density, and canopy temperature depression. In six of the eight environments, slow-wilting genotypes generally had lower RUE than fast-wilting genotypes, which is consistent with our hypothesis. Three of four slow-wilting genotypes had higher soil moisture immediately before irrigation than fast-wilting genotypes, which is also consistent with the hypothesis. Genotypic differences in CID (a proxy for WUE) were present but were not consistently related with slow wilting. No genotypic differences were detected in stomatal conductance or canopy temperature. These results suggest that multiple mechanisms involving RUE and WUE could result in soil-water conservation in these diverse genotypes.