Physiological and anatomical changes induced by drought in two olive cultivars (cv Zalmati and Chemlali)
Physiological and anatomical changes induced by drought in two olive cultivars (cv Zalmati and Chemlali)
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DOI：
10.1007/s11738-010-0516-8
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发表时间：
2011-01-01
影响因子：
2.6
通讯作者：
Hajlaoui, Hichem
中科院分区：
文献类型：
--
作者：
Boughalleb, Faycal;Hajlaoui, Hichem
研究了两个油橄榄品种（Chemlali和Zalmati）幼苗在不同水分条件下的光合气体交换、营养生长、水分关系和荧光参数以及叶片解剖特征。两岁的橄榄树，种植在温室的花盆里，两个月没有浇水。两个品种的相对生长率（RGR）、叶片水势（I-LW）和叶片相对含水量（LWC）均随水分胁迫的增加而降低。在严重干旱胁迫下，Zalmati的RGR和LWC值高于Chemlali， I-LW的下降值低于Chemlali。水分胁迫还导致光合能力和叶绿素荧光显著下降。净光合速率、气孔导度、蒸腾速率、PSII的最大光化学效率(F （v)/F (m)）和开放PSII反应中心的内在效率(F′（v)/F′(m)）随着干旱胁迫的加剧而降低。此外，干旱条件下，叶片叶绿素和类胡萝卜素含量降低，特别是在严重水分胁迫下。然而，与Chemlali相比，Zalmati植物受到的影响较小。在中等干旱胁迫下，气孔控制是影响光合作用的主要因素。在严重的干旱胁迫下，光合作用的非气孔组分受到抑制，发生光系统II失活。叶片解剖参数表明，干旱胁迫导致上表皮和栅栏叶肉厚度增加，气孔和毛状体密度增加。这些变化在cv中更具特征性。“Zalmati”。竹叶比叶面积较小，叶组织密度较高。从Zalmati植株的行为来看，其相对生长率、净同化率和叶绿素荧光参数的下降幅度较小，栅栏薄壁较厚，气孔和毛状体密度较高，我们认为该品种比cv更具耐旱性。因此，很有希望在干旱地区种植。
Photosynthetic gas exchange, vegetative growth, water relations and fluorescence parameters as well as leaf anatomical characteristics were investigated on young plants of two Olea europaea L. cultivars (Chemlali and Zalmati), submitted to contrasting water availability regimes. Two-year-old olive trees, grown in pots in greenhouse, were not watered for 2 months. Relative growth rate (RGR), leaf water potential (I-LW) and the leaf relative water content (LWC) of the two cultivars decreased with increasing water stress. Zalmati showed higher values of RGR and LWC and lower decreased values of I-LW than Chemlali, in response to water deficit, particularly during severe drought stress. Water stress also caused a marked decline on photosynthetic capacity and chlorophyll fluorescence. The net photosynthetic rate, stomatal conductance, transpiration rate, the maximal photochemical efficiency of PSII (F (v)/F (m)) and the intrinsic efficiency of open PSII reaction centres (F' (v)/F' (m)) decreased as drought stress developed. In addition, drought conditions, reduced leaf chlorophyll and carotenoids contents especially at severe water stress. However, Zalmati plants were the less affected when compared with Chemlali. In both cultivars, stomatal control was the major factor affecting photosynthesis under moderate drought stress. At severe drought-stress levels, the non-stomatal component of photosynthesis is inhibited and inactivation of the photosystem II occurs. Leaf anatomical parameters show that drought stress resulted in an increase of the upper epidermis and palisade mesophyll thickness as well as an increase of the stomata and trichomes density. These changes were more characteristic in cv. 'Zalmati'. Zalmati leaves also revealed lower specific leaf area and had higher density of foliar tissue. From the behaviour of Zalmati plants, with a smaller reduction in relative growth rate, net assimilation rate and chlorophyll fluorescence parameters, and with a thicker palisade parenchyma, and a higher stomatal and trichome density, we consider this cultivar more drought-tolerant than cv. Chemlali and therefore, very promising for cultivation in arid areas.