Water Relations and Transpiration of Quinoa (Chenopodium quinoa Willd.) Under Salinity and Soil Drying
Water Relations and Transpiration of Quinoa (Chenopodium quinoa Willd.) Under Salinity and Soil Drying
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DOI：
10.1111/j.1439-037x.2011.00473.x
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发表时间：
2011-10
影响因子：
3.5
通讯作者：
F. Razzaghi;S. H. Ahmadi;V. I. Adolf;C. R. Jensen;S. Jacobsen;M. Andersen
中科院分区：
文献类型：
--
作者：
F. Razzaghi;S. H. Ahmadi;V. I. Adolf;C. R. Jensen;S. Jacobsen;M. Andersen
干旱和盐碱是干旱和半干旱地区限制作物生长和产量的两个主要因素。研究了盐分和渐进性干旱对藜麦(Chenopodium quinoa Wild.)都是在温室实验中进行的。测定了5个盐度水平(0、10、20、30和40dsm)的灌水处理(FI0、FI10、FI20、FI20、FI30、FI40)和连续干旱(PD)处理的气孔导度(GS)、叶水势(WL)、地上部和根脱落酸浓度([ABA])和蒸腾速率。这些测量是在连续9天的干旱中进行的。结果表明，随着盐分水平的增加，土壤总水势(WT)降低，从而降低了FI和PD的GS和WL值。在干旱期间，地上部提取的木质部[ABA]的增长速度快于根提取的木质部。盐分和土壤干燥引起的WT下降，蒸腾作用减少，根系对水分吸收的表观阻力(R)增加，特别是在干旱时期的最后几天，PD0和PD40的表现更是如此。讨论了表观根阻增大的原因。在干旱期末，土壤相对有效水(RAW)在PD0达到最小值。在非盐分条件下，当RAW达到或低于0.42时，WL急剧下降，但在PD10和PD20盐分条件下，RAW的阈值分别为0.67和0.96。总之，由于土壤干燥过程中渗透势和基质势对土壤水分有效性的叠加作用，在受盐分影响的土壤中，藜麦应该在较高的生长期重新灌溉，即在土壤水分达到临界阈值水平之前，导致水分损失下降，导致气孔关闭。
Drought and salinity are the two major factors limiting crop growth and production in arid and semi-arid regions. The separate and combined effects of salinity and progressive drought in quinoa (Chenopodium quinoa Willd.) were studied in a greenhouse experiment. Stomatal conductance (gs), leaf water potential (Wl), shoot and root abscisic acid concentration ([ABA]) and transpiration rate were measured in full irrigation (FI; around 95 % of water holding capacity (WHC)) and progressive drought (PD) treatments using the irrigation water with five salinity levels (0, 10, 20, 30 and 40 dS m )1 ); the treatments are referred to as FI0 ,F I10 ,F I20 ,F I30 ,F I40 ;P D0 ,P D10 ,P D20 ,P D30 ,P D40, respectively. The measurements were carried out over 9 days of continuous drought. The results showed that increasing salinity levels decreased the total soil water potential (WT) and consequently decreased gs and Wl values in both FI and PD. During the drought period, the xylem [ABA] extracted from the shoots increased faster than that extracted from the roots. A reduction in WT, caused by salinity and soil drying, reduced transpiration and increased apparent root resistance (R) to water uptake, especially in PD0 and PD40 during the last days of the drought period. The reasons for the increase in apparent root resistance are discussed. At the end of the drought period, the minimum value of relative available soil water (RAW) was reached in PD0. Under non-saline conditions, Wl decreased sharply when RAW reached 0.42 or lower, but under the saline conditions of PD10 and PD20, the threshold values of RAW were 0.67 and 0.96, respectively. In conclusion, due to the additive effect of osmotic and matric potential during soil drying on soil water availability, quinoa should be re-irrigated at higher RAW in salt-affected soils, i.e. before the soil water content reaches the critical threshold level causing the drop in Wl resulting in stomatal closure.