林业科学  2015, Vol. 51 Issue (2): 37-43   PDF    
DOI: 10.11707/j.1001-7488.20150205
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文章信息

王林龙, 李清河, 徐军, 薛海霞, 江泽平
Wang Linlong, Li Qinghe, Xu Jun, Xue Haixia, Jiang Zeping
不同种源油蒿形态与生理特征对干旱胁迫的响应
Morphology and Physiology Characteristic Responses of Different Provenances of Artemisia ordosica to Drought Stress
林业科学, 2015, 51(2): 37-43
Scientia Silvae Sinicae, 2015, 51(2): 37-43.
DOI: 10.11707/j.1001-7488.20150205

文章历史

收稿日期：2014-11-14
修回日期：2015-01-14

作者相关文章

王林龙
李清河
徐军
薛海霞
江泽平

引用本文
王林龙, 李清河, 徐军, 薛海霞, 江泽平. 2015. 不同种源油蒿形态与生理特征对干旱胁迫的响应[J]. 林业科学, 51(2): 37-43.
Wang Linlong, Li Qinghe, Xu Jun, Xue Haixia, Jiang Zeping. 2015. Morphology and Physiology Characteristic Responses of Different Provenances of Artemisia ordosica to Drought Stress. Scientia Silvae Sinicae, 51(2): 37-43.  DOI: 10.11707/j.1001-7488.20150205
不同种源油蒿形态与生理特征对干旱胁迫的响应
王林龙1, 李清河1, 徐军2, 薛海霞1, 江泽平1    
1. 中国林业科学研究院林业研究所 国家林业局林木培育重点实验室 北京 100091；
2. 中国林业科学研究院沙漠林业实验中心 磴口 015200
收稿日期：2014-11-14；修回日期：2015-01-14
基金项目："十二五"国家科技计划专题(2012BAD16B0102)；国家自然科学基金项目(31470622)。
通讯作者：李清河
摘要：【目的】 了解干旱胁迫对不同种源油蒿的形态和生理特征的影响，同时比较不同种源油蒿的抗旱能力，为我国干旱、半干旱地区引种提供理论依据。【方法】 以毛乌素沙地、库布齐沙漠、草原荒漠过渡带的3个种源油蒿为材料，进行不同水分处理，研究在适宜、轻度干旱、重度干旱情况下不同种源油蒿株高、基径、叶面积、比叶面积、叶绿素a(Chla)、叶绿素b(Chlb)、叶绿素(a+b) 、类胡萝卜素(Car)、叶绿素a/b(Chla/b)、类胡萝卜素/叶绿素(Car/Chl)、可溶性糖、淀粉、非结构性碳水化合物(NSC)的变化。【结果】 3个种源地油蒿形态特征、光合色素含量以及NSC对干旱胁迫响应趋势一致，表现为随着干旱胁迫加剧:1) 油蒿的株高、基径、叶面积和比叶面积呈现逐渐减小趋势，其中在重度干旱情况下，库布齐沙漠油蒿的株高、叶面积、基径大于毛乌素沙地和草原荒漠过渡带油蒿，而比叶面积小于毛乌素沙地和草原荒漠过渡带油蒿； 2) 油蒿叶片的Chla，Chlb，Chl(a+b)，Car， Chla/b和Car/Chl呈现先增大后减小的趋势，其中在重度干旱情况下，库布齐沙漠油蒿叶片的Chla，Chlb，Chl(a+b) 大于毛乌素沙地和草原荒漠过渡带油蒿叶片，而3个种源地油蒿的Car含量以及Car/Chl相差不大，Chla/b表现为草原荒漠过渡带最大，毛乌素沙地其次，库布齐沙漠最小； 3)油蒿叶片可溶性糖、淀粉和NSC含量呈现先减小后增大的趋势，其中在重度干旱情况下，草原荒漠过渡带油蒿叶片的可溶性糖、淀粉和NSC含量均大于库布齐沙漠和毛乌素沙地油蒿叶片，而库布齐沙漠油蒿叶片的可溶性糖、淀粉和NSC含量又大于毛乌素沙地油蒿叶片； 在轻度干旱情况下，库布齐沙漠油蒿叶片的可溶性糖、淀粉和NSC含量大于草原荒漠过渡带和毛乌素沙地油蒿叶片。【结论】 从3个种源地油蒿株高、基径、叶面积、比叶面积、Chla、Chlb、Chl(a+b)、Car、Chla/b、Car/Chl、可溶性糖、淀粉、NSC等指标比较中，推测来自库布齐沙漠的油蒿较毛乌素沙地、草原和荒漠过渡带油蒿具有更强的抗旱性。
关键词： 油蒿    种源    水分胁迫    形态    生理    响应    
Morphology and Physiology Characteristic Responses of Different Provenances of Artemisia ordosica to Drought Stress
Wang Linlong1, Li Qinghe1, Xu Jun2, Xue Haixia1, Jiang Zeping1    
1. Laboratory of Tree Breeding and Cultivation, State Forestry Administration Research Institute of Forestry, CAF Beijing 100091;
2. Experimental Center for Desert Forestry, CAF Dengkou 015200
Abstract: [Objective]In this study, we investigated effects of drought stress on morphology and physiology characteristics of Artemisia ordosica and compare with the drought-resistant ability of three different provenances of A. ordosica, to provide a theoretical basis for the introduction of the species to China's arid and semi-arid area.[Method]Three different provenances of A. ordosica were collected from Mu Us Sandy land, Kubuqi desert, and Desert-steppe transitional zone, and subjected to different soil moisture to investigate the changes of plant height, stem size, leaf area, Sla, content of Chla, Chlb, Chl(a+b) and Car, Chla/b and Car/Chl and content of starch, soluble sugars and NSC.[Result]The response of morphology characteristics, photosynthetic pigment content, and contents of starch, soluble sugars and NSC of three different provenances of A. ordosica to drought stress was consistent. Namely, as the drought stress increased, 1)plant height, stem diameter, leaf area and SLA, showed a trend of gradual decrease. The plant height, stem size, and leaf area of A. ordosica from Kubuqi desert were greater than those from Mu Us Sandy land and Desert-steppe transitional zone under the severe drought stress. However Sla of the provenance from Kubuqi desert was less than that from Mu Us Sandy land and Desert-steppe transitional zone.2)Chla,Chlb,Chl(a+b),and Car contents、Chla/b and Car/Chl of A. ordosica leaves showed a trend of first increase and then decrease under drought stress. Contents of Chla,Chlb,Chl(a+b) of A. ordosica leaves from Kubuqi desert were higher than A. ordosica from Mu Us Sandy land and Desert-steppe transitional zone under the severe drought stress. However there were no significant differences in contents of Car and Car/Chl of the three different provenances. The Chla/b of A. ordosica from Desert-steppe transitional zone was greatest, followed by that from Mu Us Sandy land, and then by that from Kubuqi desert.3)Contents of starch, soluble sugars and NSC of three different provenances leaves showed a trend of first decrease and then increase. Contents of starch, soluble sugars and NSC of A. ordosica from Desert-steppe transitional zone were higher than A. ordosica from Kubuqi desert and Mu Us Sandy land under severe drought stress, and contents of starch, soluble sugars and NSC of A. ordosica from Kubuqi desert were higher than those of A. ordosica from Mu Us Sandy land. Contents of starch, soluble sugars and NSC of A. ordosica from Kubuqi desert were higher than those of A. ordosica from Mu Us Sandy land and Desert-steppe transitional zone under slight drought stress.[Conclusion]Through the comparison of morphology and physiology characteristics of three different provenances of A. ordosica, we find that the drought resistance of A. ordosica from Kubuqi desert is stronger than A. ordosica from Mu Us Sandy land and Desert-steppe transitional zone.
Key words: Artemisia ordosica    provenances    drought stress    morphology    physiology    response    

随着全球暖干化，干旱胁迫普遍存在(Chaves et al., 2002; Verslues et al., 2006)，而且呈加剧趋势(Wassmann et al., 2009)。有研究表明，干旱环境严重影响植物的生长和发育(Shao et al., 2009; Hsiao et al., 1976; Bradford et al., 1982; McDonald et al., 1993)，干旱加剧对植物性能有负面影响(Walther et al., 2002)，如随着干旱加剧，植物通过减小株高、基径、叶面积、比叶面积和总生物量(Maes et al., 2009; Liu et al., 2004; Li et al., 2000; Wu et al., 2008)，增大根冠比(Wu et al., 2000)等策略来适应环境胁迫，增强其抗旱性。不仅不同物种之间对水分胁迫响应有差异，而且同一物种不同种群之间和不同发育阶段对水分胁迫的敏感程度也不同(Demirevska et al., 2009；Zhang et al., 2004)。干旱胁迫除了对形态特征有影响之外，还对植物的叶绿体造成伤害，使叶绿素和类胡萝卜素的含量下降(Zhang et al., 1996)。

油蒿(Artemisia ordosica)为菊科(Compositae)蒿属(Artemisia)植物，是我国特有优良固沙半灌木植物，分布在内蒙古、宁夏、陕西和甘肃等温带沙地，分布中心在鄂尔多斯高原。我国温带半干旱区的沙地中，油蒿具有很强的适应性，成为植被演替过程中最重要的物种之一(刘家琼等，1988)。目前国内对油蒿、柽柳(Tamarix chinensis)、沙冬青(Ammopiptanthus mongolicus)等沙生植物进行过抗旱研究，但对于不同种源油蒿的抗旱方面研究少有报道。经过野外观察发现，油蒿在沙漠、沙地及草原与荒漠过渡带都有分布，其长势存在差异，因此本文以毛乌素沙地、库布齐沙漠、荒漠化草原和草原化荒漠过渡带3个种源地的油蒿为材料，进行不同水分处理，了解不同种源油蒿对干旱胁迫的形态和生理特征响应趋势变化，进而比较对不同种源抗旱能力，为我国干旱、半干旱地区引种提供理论依据。

1 材料与方法 1.1 试验材料

从库布齐沙漠、毛乌素沙地、荒漠化草原和草原化荒漠过渡带3个地点(分别以DEOR，WSOR和HYOR表示)采集一定数量具有代表性的母株种子(采集地的经纬度、年降水量和年蒸发量见表 1)，并于2014年4月中旬在中国林业科学研究院温室内进行营养钵(规格为5 cm×5 cm，基质为蛭石∶珍珠岩∶草炭土=1∶3∶6)育苗，待幼苗出现后，选取生长状况一致的植株移栽到花盆(规格15 cm×15 cm×20 cm)，基质为蛭石∶ 珍珠岩∶草炭土=2∶3∶5。待植株完全成活后，以称重法进行水分处理，并隔期观测数据。3个种源(DEOR，WSOR，HYOR)和3种水分处理(5%，15%，30%的土壤含水量)随机组合成9个试验组(每组5株植株)。水分处理过程中，待移栽的植株成活后，每隔3天浇1次水，并称重，确保土壤含水量为5%，15%，30%，直至2014年9月底破坏性采样结束。为了减小试验环境差异，将9个试验组系统均放置在中国林业科学研究院温室苗床上。

表 1 不同种源油蒿种子采集地的降水量和蒸发量 Tab.1 Precipitation and evaporation of the A. ordosica populations where the seeds used in this study were collected
1.2 叶片形态测定

2014年10月初，于植株各方位选取5~8片健康叶片，用Yaxin-1241叶面积仪(北京雅欣理仪科技有限公司)测定各植株叶片面积。将叶片装入信封内烘干至恒重(78 ℃，48 h)，测定干质量。比叶面积(specific leaf area，SLA，cm2·g-1)计算公式为：SLA=总叶面积(cm2)/叶片干质量(g)。株高和基径分别用5 m钢卷尺和数显游标卡尺测定。

1.3 叶片光合色素及非结构性碳水化合物测定

光合色素含量、可溶性糖和淀粉的测定参照陈建勋等(2006)的方法，非结构性碳水化合物(non-structural carbohydrates，NSC)含量=可溶性糖总量+淀粉含量。

1.4 数据处理

对以上各项指标采用双因素方差分析和单因素方差分析及多重比较(Duncan法检验)，比较不同种源对水分胁迫的形态和生理特征响应差异。所有分析在SPSS 19.0软件下完成，图表采用Microsoft Excel 2007和Originlab Pro8.0软件进行绘制。

2 结果与分析 2.1 油蒿形态特征响应

随着干旱加剧，油蒿的株高、基径、叶面积和比叶面积逐渐减小(图 1)，而且不同水分对株高、基径、叶面积和比叶面积影响极显著(P＜0.01或P＜0.001)(表 2)。其中在重度干旱情况下，DEOR的株高分别为HYOR和WSOR株高的1.15和1.16倍；DEOR和WSOR的基径相差不大，比HYOR的基径大12%；DEOR的叶面积大于HYOR和WSOR，分别为其叶面积的1.25和1.5倍；而 WSOR的比叶面积(SLA)均大于DEOR和HYOR，分别为其SLA的1.09和1.1倍。

图 1 不同种源油蒿形态特征对干旱胁迫的响应 Fig. 1 Morphological characteristics of different provenances of A. ordosica under different water stress(mean±S.E.) W5%：土壤含水量为5% 5% soil water content； W15%; 土壤含水量为15% 15% soil water content; W30%：土壤含水量为30% 30% soil water content. 不同字母表示处理间差异显著(P < 0.05)Different letters meant significant difference among different treatments at 0.05 level.
表 2 不同种源、水分及交互作用对油蒿形态和生理特征的影响(F值)① Tab.2 Morphological and physiological characteristics of A. ordosica to different provenances，different water stress and their interactive effects(F value)
2.2 油蒿光合色素含量响应

随着干旱加剧，油蒿的Chla，Chlb，Chl(a+b)，Car，Chla/b和Car/Chl呈现先增大后减小的趋势(表 3)，而不同水分对油蒿的Chla，Chl(a+b)，Car和Car/Chl影响极显著(P＜0.001)(表 2)。其中在重度干旱情况下，DEOR的Chla含量和WSOR相差不大，分别为0.70和0.68，是HYOR的1.15倍；DEOR的Chlb，Chl(a+b)含量均大于HYOR和WSOR，分别为HYOR和WSOR的1.5，1.27和1.26，1.12倍；WSOR，HYOR和DEOR的Car含量相差不大，分别为0.03，0.02和0.02；而HYOR的Chla/b最大，WSOR其次，DEOR最小；WSOR，HYOR和DEOR的Car/Chl相差不大。

表 3 不同种源油蒿光合色素含量对干旱胁迫的响应① Tab.3 Photosynthetic pigment content of different provenances of A.ordosica under different water stress
2.3 油蒿叶片非结构性碳水化合物(NSC)响应

随着干旱加剧，可溶性糖、淀粉和NSC的含量呈先减小后增大的趋势(表 4)，而不同水分对可溶性糖、淀粉和NSC影响极显著(P＜0.001)(表 2)。其中在重度干旱情况下，HYOR的可溶性糖、淀粉和NSC含量均大于DEOR和WSOR，而DEOR的可溶性糖、淀粉和NSC含量又大于WSOR；在轻度干旱情况下，DEOR的可溶性糖、淀粉和NSC含量大于HYOR和WSOR。

表 4 不同种源油蒿淀粉、可溶性糖和NSC含量对干旱胁迫的响应 Tab.4 Starch,soluble sugar and NSC content of different provenances of A. ordosica under different water stress
3 结论与讨论

植株在受到干旱胁迫时，其形态和生理特征都会发生变化。如随着干旱加剧，植物株高、基径、叶面积、比叶面积显著减小(Anjum et al., 2011; Liu et al., 2004; Zhang et al., 2004; 肖春旺等，2001；谢小玉等，2014; 井大炜等，2014)，这与本文研究结果相一致。株高、基径、叶面积减小，是细胞膨压减小和叶片衰老造成的(Manivannan et al., 2007)，从而减小了有效光合叶面积；干旱胁迫造成叶面积减小，可能是通过减小光合作用来抑制叶片扩张(Rucker et al., 1995)；比叶面积减小，是植株对干旱胁迫的响应，增强其抗干旱性，是植株适应干旱环境的结果。

叶绿素方面，表现为随着干旱加剧，油蒿的Chla，Chlb，Chl(a+b)，Car，Chla/b和Car/Chl呈现先增大后减小的趋势。Chla，Chlb和Chl(a+b)的变化趋势与李芳兰等(2009)的研究结果不同，与井大炜等(2014)、Guerfel等(2009)、Manivannan等(2007)、谢小玉等(2014)、孙景宽等(2011)和潘昕等(2014)研究结果相一致。随着干旱胁迫加剧，导致叶绿素含量降低，可能是叶绿体膜受到破坏所造成的，从而造成叶肉细胞水分缺失(Anjum et al., 2011)，而水分是光合作用的重要物质，所以会对植物生长产生不利影响，这也解释了植物株高、基径、叶面积、比叶面积会显著减小的原因。Car是植物光合作用色素蛋白复合体不可缺少的组分，其可以作为捕光色素，并且在保护光合器官免受单线态氧的伤害中起重要作用(Siefernann-Harms，1985; 1987;Demmig-adams，1990;Young，1991;Dutton，1997; 张其德等，1997)。本研究中，Car和Car/Chl的变化趋势一致，即先增大后减小，表明随着干旱加剧，Car和Car/Chl会有一个上升的过程，从而提高其抗旱能力，当干旱继续加剧，则引起细胞水分严重缺失，对 Car和Car/Chl产生一定的影响。

随着干旱加剧，可溶性糖、淀粉和NSC含量呈先减小后增大的趋势。而NSC整体上呈增大趋势，这可能是在轻度干旱情况下，会促进植物的新陈代谢，加快了对碳的投资以抵抗干旱环境；在重度干旱情况下，植物细胞水分的缺失，会降低植物新陈代谢的速度，直接限制了碳的投资，导致大量NSC在植物体内积累(郑云普等，2014)。在重度干旱情况下，不同种源油蒿的形态特征和生理特征表现出差异性，如DEOR的株高、基径、叶面积、Chla、Chlb、Chl(a+b)均大于HYOR和WSOR，而可溶性糖、淀粉和NSC含量与WSOR相差不大，但大于HYOR，这说明来自库布齐沙漠的油蒿较毛乌素沙地和荒漠化草原与草原化荒漠过渡带的油蒿表现出更强的抗旱性。库布齐沙漠的油蒿，由于长期处于干旱环境，其结构和生理性状发生变化来适应干旱胁迫，随着不断的演替，这些结构和生理性状发生遗传变异，从而使植株适应长期的干旱胁迫。

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