Stomatal and non-stomatal restrictions to carbon assimilation in soybean (Glycine max) lines differing in water use efficiency
Stomatal and non-stomatal restrictions to carbon assimilation in soybean (Glycine max) lines differing in water use efficiency
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DOI：
10.1016/s0098-8472(02)00041-2
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发表时间：
2002-12-01
影响因子：
5.7
通讯作者：
Earl, HJ
中科院分区：
文献类型：
--
作者：
Earl, HJ
水分利用效率（WUE，单位水分蒸腾产生的作物干物质数量）的遗传变异性已在广泛的作物物种中得到证实。与已建立的理论相一致，具有较高WUE的基因型通常被发现保持较低的叶片内部CO2浓度（c（i）），如通过碳同位素鉴别所估计的。然而，较低的c（i）可能是由于气孔导度降低，叶肉（非气孔）导度增加，或两者的组合。当发现WUE的基因型变异时，确定这种变异是否来自气孔或非气孔对CO2吸收的限制差异，对于植物育种目的可能是重要的。大豆品种杨先前被证明有较高的WUE比大豆植物引进PI 416937时，都生长在周期性干旱胁迫下，但气孔和非气孔因素的相对重要性是未知的。在目前的工作中，这些大豆品系之间的WUE的差异被发现是小于以前报道的，也被证明是组成的性质，即，它发生在循环干旱胁迫和水分充足的条件下。叶片气体交换的测量显示，cv。杨保持较低的c（i）和较高的叶片水平WUE比PI 416937，如预期的。敏感性分析表明，在稳态气体交换条件下观察到的c（i）的差异可以完全归因于气孔限制光合作用的差异。气孔导度和c（i）的基因型差异也进行了研究波动光合有效辐射下，在某些情况下，被认为是更明显的比在稳态条件下。(C)2002 Elsevier Science B.V.保留所有权利。
Genetic variability for water use efficiency (WUE, the quantity of crop dry matter produced per unit water transpired) has been demonstrated in a wide range of crop species. In agreement with established theory, genotypes with higher WUE are often found to maintain lower leaf internal CO2 concentration (c(i)), as estimated by carbon isotope discrimination. However, lower c(i) may result from reduced stomatal conductance, increased mesophyll (non-stomatal) conductance, or a combination of both. When genotypic variation for WUE is found, it may be important for plant breeding purposes to define whether such variation arises from differences in stomatal or non-stomatal restrictions to CO2 uptake. The soybean cultivar Young was previously shown to have higher WUE than the soybean plant introduction PI416937 when both were grown under cyclic drought stress, but the relative importance of stomatal and non-stomatal factors was not known. In the present work, the difference in WUE between these soybean lines was found to be smaller than previously reported, and was also demonstrated to be constitutive in nature; that is, it occurred under both cyclic drought stress and water-replete conditions. Leaf gas exchange measurements revealed that cv. Young maintained lower c(i) and higher leaf-level WUE than PI416937, as expected. Sensitivity analysis indicated that the observed differences in c(i) under steady-state gas exchange conditions could be attributed entirely to differences in stomatal limitations to photosynthesis. Genotype differences in stomatal conductance and c(i) were also examined under fluctuating photosynthetically active radiation, and in some cases were found to be even more pronounced than under steady-state conditions. (C) 2002 Elsevier Science B.V. All rights reserved.