Water-use efficiency, leaf area and leaf gas exchange of cowpeas under mid-season drought
Water-use efficiency, leaf area and leaf gas exchange of cowpeas under mid-season drought
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DOI：
10.1016/s1161-0301(03)00038-8
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发表时间：
2004-04-01
影响因子：
5.2
通讯作者：
Herzog, H
中科院分区：
文献类型：
--
作者：
Anyia, AO;Herzog, H
10个豇豆（Vigna unguiculata L.）“沃普。“）基因型在生长室中在充分浇水的条件下生长直至早期开花，然后经受水分亏缺或持续充分浇水。通过停灌至土壤水势为-75 kPa，维持10 d，诱导水分亏缺。研究了水分亏缺对小麦水分利用效率（WUE）、叶面积、比叶面积（SLA）、叶面积比（LAR）和叶片气体交换（同化、蒸腾、气孔导度和内部CO2浓度）的影响。缺水处理减少了21%的平均用水量。这导致了基因型间生物量减少11%至40%以上。生物量的减少是由于水分亏缺时叶片气体交换和叶面积的下降。水分亏缺使两个基因型（IFH 27-8和Lobia）的WUE提高了约20%，但在大多数基因型中引起中度至巨大的降低。高相对含水量（RWC）的叶片保持在一些基因型的气孔关闭和叶面积的减少。通过保持较高的叶片含水量来避免干旱与叶面积以及其SLA呈负相关。水分亏缺下高同化率与高RWC相关。光合速率的下降主要是气孔关闭的结果，但也有非气孔调节的作用，水分利用效率与瞬时水分利用效率（IWUE）无直接关系，但IWUE与叶片内部CO2浓度（c（i））呈负相关，ci与SLA呈中度相关。总的来说，叶气体交换参数的显着的基因型变化，这可以给一些指标的优势，比较豇豆基因型在干旱条件下的农艺适应性。WUE和IWUE之间缺乏相关性是由于叶片气体交换的瞬时测量，可以通过计算来校正以反映整个季节。(C)2003 Elsevier B. V.保留所有权利。
Ten cowpea (Vigna unguiculata L. "Walp.") genotypes were grown in a growth chamber under well-watered conditions up to early flowering and were then either subjected to water deficit or were continually well-watered. Water deficit was induced by withholding irrigation until the soil water potential was -75 kPa, which was then maintained for 10 days. Variation in water use efficiency (WUE), leaf area, specific leaf area (SLA), leaf area ratio (LAR) and leaf gas exchange (i.e. assimilation, transpiration, stomata conductance and internal CO2 concentration) in response to water deficit were investigated. Water deficit treatment reduced mean water use by 21%. This caused between 11 and more than 40% reduction of biomass across the genotypes. Reductions in biomass were due to decline in leaf gas exchange and leaf area during water deficit. Water deficit improved the WUE of two genotypes (IFH 27-8 and Lobia) by approximately 20%, but caused moderate to huge reductions in most genotypes. High relative water content (RWC) of leaves was maintained in some of the genotypes by stomata closure and a reduction of leaf area. Drought avoidance by maintaining high leafwater content was negatively associated with leaf area as well its SLA. High assimilation rate under water deficit was associated with high RWC. Decline in assimilation rate were doe mainly to stomata closure, however, some evidence of non-stomatal regulation were also found. WUE and instantaneous water use efficiency (IWUE, a molar ratio of assimilation to transpiration) were not directly associated, but IWUE and leaf internal CO2 concentration (c(i)) were negatively related while ci was also moderately related with SLA. Overall, significant genotypic variations in leaf gas exchange parameters were found, which can give some indications of superiority when comparing cowpea genotypes for agronomic fitness under drought. The lack of relationship between WUE and IWUE was due to the instantaneous measurement of leaf gas exchange, which can be corrected by calculations to reflect the entire season. (C) 2003 Elsevier B.V. All rights reserved.