首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 125 毫秒
1.
新疆2种盐生补血草营养器官的解剖学研究   总被引:5,自引:0,他引:5  
周玲玲  刘萍  王军 《西北植物学报》2007,27(6):1127-1133
采用叶片离析法和石蜡切片法,对生长在新疆盐渍环境中的大叶补血草[Limonium gmelinii(Willd.) Kuntze]和耳叶补血草[Limoniumotolepis(Schrenk) Kuntze]的营养器官解剖学特征进行了观察研究.结果显示,2种补血草属典型泌盐植物,茎和叶片表皮上分布有多细胞组成的盐腺;叶表皮细胞排列紧密,其外切向壁增厚,表皮外还被有厚的角质层;上下表皮都有气孔,气孔与表皮细胞平齐,为不等型气孔;其中大叶补血草为异面叶,而耳叶补血草为等面叶.2种补血草茎中都散生有多轮维管束;大叶补血草根中还有大量通气组织等.研究结果表明,2种补血草的解剖结构表现出与其生境相适应的特征.  相似文献   

2.
四种野生盐生植物解剖结构与抗旱耐盐性   总被引:5,自引:0,他引:5  
为了解盐生植物的解剖结构与抗盐性和抗旱性的关系,以二色补血草、草木樨,艾蒿、猪毛菜为材料,通过徒手切片和显微观察了植物的叶、茎、腺毛、分泌腔、气孔、表皮毛分布和结构。结果显示:猪毛菜的气孔密度低、气孔器小,表皮毛密集,叶面积小,抗旱能力最强;艾蒿的表皮毛长、浓密,气孔密度较低、气孔较小,抗旱性较强;二色补血草表皮毛短、密集,但气孔密度较高、气孔器较大,抗旱性较差;草木樨表皮毛短、稀疏,气孔密度较高、气孔也较大,抗旱性最差;二色补血草有发达的内分泌和外分泌组织,根系吸收的大量盐份积累在分泌腔中,并通过盐腺排出叶片,是排盐植物,耐盐性强;猪毛菜具有发达的内分泌组织,有大量分泌腔,且有粘液细胞和大量薄壁细胞,是耐盐植物,耐盐性强;草木樨具有较多的盐腺,是泌盐植物,耐盐性较强;艾蒿无盐腺等分泌组织。猪毛菜可以作为盐碱地"生物脱盐器"。  相似文献   

3.
应用扫描电镜和光学显微镜对山西运城盐湖周围盐渍环境中4种藜科(Chenopodiaceae)盐生植物叶的结构进行了比较解剖研究.结果表明,碱蓬(Suaeda glauca Bunge)和盐地碱蓬(Suaeda salsa (Linn.) Pall.)属真盐生植物,结构特征相似:叶线形、肉质化,表皮上气孔器密集,叶肉具有发达的储水组织细胞和栅栏组织.灰绿藜(Chenopodium glaucum Linn.)和西伯利亚滨藜(Atriplex sibirica Linn.)为泌盐盐生植物,其中,灰绿藜具有双细胞构成的盐腺,西伯利亚滨藜则具有盐囊泡,此外,两种泌盐盐生植物中存在的异细胞和含晶细胞,对适应盐生环境有积极意义.从表皮细胞来看,4种植物的叶都有相同的适盐特征.总之,4种藜科盐生植物的叶片结构具有适盐的共同性和个体的多样性特征.  相似文献   

4.
四种补血草属植物叶片泌盐结构的扫描电镜观察   总被引:10,自引:1,他引:9  
周玲玲  刘萍  陆嘉惠 《植物研究》2006,26(6):667-671
利用扫描电镜技术,对4种补血草属植物大叶补血草(Limonium gmelinii (Willd.) Kuntze)、耳叶补血草(Limoniu otolepis (Schrenk) Kuntze)、繁枝补血草(Limonium myrianthum (Schrenk) Kuntze)和簇枝补血草(Limonium auream)的叶表面进行了研究,以探讨植物微形态结构与生态环境的关系。结果表明,这4种植物的上下表皮都分布有盐腺,且上表皮的盐腺密度大于下表皮,盐腺的基本结构相同,多由20个细胞构成,其中4个分泌细胞顶端的角质层中央有一小孔,植物体靠盐腺的泌盐孔泌盐。但4种植物在盐腺的密度、盐腺的大小、盐腺与周围表皮细胞的位置等方面存在差异。植物在对盐碱生境的长期适应过程中,促使其强烈地分化出泌盐结构,因而,具有明显的生态适应性。  相似文献   

5.
运城盐湖4种藜科盐生植物叶的比较解剖研究   总被引:1,自引:0,他引:1       下载免费PDF全文
应用扫描电镜和光学显微镜对山西运城盐湖周围盐渍环境中4种藜科(Chenopodiaceae)盐生植物叶的结构进行了比较解剖研究。结果表明,碱蓬(Suaeda glauca Bunge)和盐地碱蓬(Suaedasalsa(Linn.)Pall.)属真盐生植物,结构特征相似:叶线形、肉质化,表皮上气孔器密集,叶肉具有发达的储水组织细胞和栅栏组织。灰绿藜(Chenopodium glaucum Linn.)和西伯利亚滨藜(Atriplex sibirica Linn.)为泌盐盐生植物,其中,灰绿藜具有双细胞构成的盐腺,西伯利亚滨藜则具有盐囊泡,此外,两种泌盐盐生植物中存在的异细胞和含晶细胞,对适应盐生环境有积极意义。从表皮细胞来看,4种植物的叶都有相同的适盐特征。总之,4种藜科盐生植物的叶片结构具有适盐的共同性和个体的多样性特征。  相似文献   

6.
二色补血草叶片泌盐结构的扫描电镜观察   总被引:14,自引:1,他引:13  
对二色补血草盐泉结构进行比较研究,发现二色补血草叶下表皮具有花型盐腺,这些盐腺是由基细胞和帽细胞构成,植物体靠盐腺的泌盐孔和基细胞破碎释盐,表明二色补血草具有演化较高级的双重泌盐结构,是二色补血草能在盐碱地生长而不受盐害的主要原因。  相似文献   

7.
安徽景天属(Sedum)植物叶表皮研究   总被引:4,自引:2,他引:2  
郑艳 《植物研究》1999,19(3):292-297
利用光学显微镜和扫描电子显微镜观察安徽省12种景天属(Sedum)植物的叶表皮,统计并测量报气孔类型,气孔大小,气孔密度及气孔指数等,描述了表皮角质膜,蜡质纹饰及气孔外拱盖的有关特征。结果表明:景天属植物叶表皮气孔器为不等细胞型。气孔器类型,表皮细胞形状及垂周壁式样,角质膜,蜡质纹饰等,种间无差异或极小,而气孔大小,气孔器分布特征,气孔密度,表皮毛等种间差异较大,建议在种间区分上将差异大的特征作为  相似文献   

8.
星星草营养器官适应盐胁迫的结构特征   总被引:8,自引:0,他引:8  
采用0.6%Na2CO3胁迫处理星星草[Puccinellia tenuiflora(Turcz.)Scribn.et Merr.]幼苗,光镜和电镜观察其根和叶的显微和超微结构。结果表明,星星草根的表皮向外突出形成密集的根毛;外皮层由1~2层细胞组成,排列较紧密;中皮层薄壁细胞排列疏松,形成发达的通气组织;内皮层呈典型的五面加厚;中柱鞘排列紧密,其壁加厚;初生木质部与初生韧皮部相间排列,初生木质部为5~7原型,中央为后生木质部导管,无髓存在。叶的表皮有表皮毛和丰富的蜡质层;叶上表皮泡状细胞数目较少,且深陷;气孔下陷,其下有较大的气室;叶脉有大、中、小3种维管束,大、中型维管束为C3型,小型维管束为C4型。星星草可能是介于C3和C4植物之间的类型,具有耐盐碱及耐干旱特征。  相似文献   

9.
安徽黄精属(Polygonatum)植物叶表皮研究   总被引:11,自引:2,他引:9       下载免费PDF全文
郑艳  王洋  周海滨  徐如松  李阿山  张定成   《广西植物》1999,19(3):263-266+294
利用光学显微镜及扫描电子显微镜观察了安徽省黄精属9种植物的叶表皮;统计并测量了气孔类型、气孔大小、气孔密度及气孔指数等;描述了表皮角质膜、蜡质纹饰、气孔的形状及气孔外拱盖等有关特征。结果表明:黄精属植物叶表皮气孔器类型属只有2个保卫细胞而无任何副卫细胞的单子叶植物气孔器类型。气孔的某些特征,如气孔器类型、气孔器分布特征、表皮细胞形状及垂周壁式样、角质层及蜡质纹饰等在种间差异不大,可作种间区别的次级特征用。  相似文献   

10.
在光学显微镜和扫描电镜下,对东亚地区帚菊木族及其南美相关类群共12属31个种的叶表皮进行了观察.研究发现气孔器普遍存在于叶的下表皮,少数种的上表皮也有分布,气孔器主要为星型和无规则型两种类型.叶表皮细胞为多边形和不规则形,垂周壁平直弓形、浅波状或波浪状.气孔器表面观为椭圆形和近圆形,气孔外拱盖内缘近平滑至浅波状,其中 Macroclinidium 较为特殊,具有双层气孔外拱盖.叶表面通常光滑无蜡质或角质,部分种叶表面具薄片状或层状蜡质.研究表明,叶表皮特征在种间一致性较高,但在属间,特别是属群和亚族间存在一定差异.  相似文献   

11.
Soil salinity poses a serious threat to agriculture productivity throughout the world. Studying mechanisms of salinity tolerance in halophytic plants will provide valuable information for engineering plants for enhanced salt tolerance. Monocotyledonous Puccinellia tenuiflora is a halophytic species that widely distributed in the saline-alkali soil of the Songnen plain in northeastern China. Here we investigate the molecular mechanisms underlying moderate salt tolerance of P. tenuiflora using a combined physiological and proteomic approach. The changes in biomass, inorganic ion content, osmolytes, photosynthesis, defense-related enzyme activities, and metabolites in the course of salt treatment were analyzed in the leaves. Comparative proteomic analysis revealed 107 identities (representing 93 unique proteins) differentially expressed in P. tenuiflora leaves under saline conditions. These proteins were mainly involved in photosynthesis, stress and defense, carbohydrate and energy metabolism, protein metabolism, signaling, membrane, and transport. Our results showed that reduction of photosynthesis under salt treatment was attributed to the down-regulation of the light-harvesting complex (LHC) and Calvin cycle enzymes. Selective uptake of inorganic ions, high K(+)/Na(+) ratio, Ca(2+) concentration changes, and an accumulation of osmolytes contributed to ion balance and osmotic adjustment in leaf cells. Importantly, P. tenuiflora plants developed diverse reactive oxygen species (ROS) scavenging mechanisms in their leaves to cope with moderate salinity, including enhancement of the photorespiration pathway and thermal dissipation, synthesis of the low-molecular-weight antioxidant α-tocopherol, and an accumulation of compatible solutes. This study provides important information toward improving salt tolerance of cereals.  相似文献   

12.
Plants maintained in high soil salinity generally develop particular structures to either tolerate or survive such adverse environments. Excretion of excess ions by special salt glands or other similar structures is a well-known phenomenon for regulating the mineral content of many halophytes. However, the three chenopod halophytes of Suaeda inhabit high saline soils, yet they exhibit no signs of salt excretion structures. The current study has been undertaken to assess the structural attributes of these halophytes to reveal their cellular characteristics during growth in salt tolerance. Transmission and scanning electron microscopy, as well as ion chromatography, have been employed for the study. One of the most noticeable features uncovered was the epidermal cutinization shown to be heavy on the outer epidermis and characterized externally by thick wax plates. Numerous vesicles and membranous invagination in the vacuoles were common features within the mesophyll cytoplasm. Invaginations of the vacuolar and/or plasma membrane frequently formed secondary vacuoles which later became distinct, membrane-bound compartments. Significant accumulation of solid sodium chloride salts was well demonstrated in the vacuoles of air-dried epidermis. Finally, salt tolerance mechanisms in these Suaeda have been discussed with respect to other halophyte modifications that improve salt tolerance in various ways.  相似文献   

13.
Populations of three salt tolerant forage grasses (Cynodon dactylon, Imperata cylindrica, and Sporobolus arabicus) were collected from the salt-affected soils of the Salt Range and normal non-saline soils of the Faisalabad region to assess their mechanism of adaptation to saline stress by determining ion relations and some specific anatomical modifications. The population of S. arabicus from the Salt Range showed increased growth (root and shoot length, and root and shoot dry weights) under saline conditions. Salt tolerance in this species was related to structural modifications such as increased area of root, stem, leaf blade, and leaf sheath for toxic ion accumulation, increased vesicular hair density in leaves and aerenchyma formation in leaf sheath for ion exclusion. Uptake of toxic ions was high in the Salt Range population of C. dactylon and salt tolerance was related to ion exclusion through specific leaf structural modifications such as vesicular hairs. Salt tolerance in the Salt Range population of I. cylindrica was mainly associated with restricted uptake of toxic Na+ and Cl at root level, and accumulation of toxic ions via increased succulence in leaf blades and leaf sheaths in addition to some excretion of toxic ions through leaf sheath aerenchyma.  相似文献   

14.
Puccinellia tenuiflora is a useful monocotyledonous halophyte that might be used for improving salt tolerance of cereals. This current work has shown that P. tenuiflora has stronger selectivity for K+ over Na+ allowing it to maintain significantly lower tissue Na+ and higher K+ concentration than that of wheat under short- or long-term NaCl treatments. To assess the relative contribution of Na+ efflux and influx to net Na+ accumulation, unidirectional 22Na+ fluxes in roots were carried out. It was firstly found that unidirectional 22Na+ influx into root of P. tenuiflora was significantly lower (by 31–37%) than in wheat under 100 and 150 m m NaCl. P. tenuiflora had lower unidirectional Na+ efflux than wheat; the ratio of efflux to influx was similar between the two species. Leaf secretion of P. tenuiflora was also estimated, and found the loss of Na+ content from leaves to account for only 0.0006% of the whole plant Na+ content over 33 d of NaCl treatments. Therefore, it is proposed that neither unidirectional Na+ efflux of roots nor salt secretion by leaves, but restricting unidirectional Na+ influx into roots with a strong selectivity for K+ over Na+ seems likely to contribute to the salt tolerance of P. tenuiflora .  相似文献   

15.
陈刚  杨威  孙国荣  彭永臻  周晓阳  周卫东  杜坤  张彪 《生态学报》2007,27(12):5408-5413
对不同强度Na2CO3胁迫处理下星星草幼苗叶片表皮和叶肉细胞中K、Na的透射电镜X-射线电子探针显微分析和叶片表面扫描电镜X-射线电子探针显微分析,结果表明:在相同胁迫强度下,无论是表皮细胞还是叶肉细胞的细胞壁和液泡中的Na相对含量均明显高于细胞质中的Na相对含量,并且K的相对含量均明显比相应部位Na的相对含量高,细胞壁与液泡中的Na相对含量变化范围非常接近。在Na2CO3胁迫浓度低于0.1molL^-1时,在相同胁迫强度下,K的相对含量高于Na的相对含量,使细胞质保持相对高的K/Na比。而尽管向细胞壁和液泡分流了大量的Na,但是细胞质中的Na相对含量仍然随着Na2CO,胁迫强度的增加而增加,一方面证明星星草在Na2CO3胁迫下维持相对高的K/Na比的能力是有一定限度的,另一方面暗示星星草作为盐生植物在盐碱环境中一定程度上Na可以部分地代替K而行使部分K的生理功能。  相似文献   

16.
陈刚  杨威  孙国荣  彭永臻  周晓阳  周卫东  杜坤  张彪 《生态学报》2007,27(12):5408-5413
对不同强度Na2CO3胁迫处理下星星草幼苗叶片表皮和叶肉细胞中K、Na的透射电镜X-射线电子探针显微分析和叶片表面扫描电镜X-射线电子探针显微分析,结果表明:在相同胁迫强度下,无论是表皮细胞还是叶肉细胞的细胞壁和液泡中的Na相对含量均明显高于细胞质中的Na相对含量,并且K的相对含量均明显比相应部位Na的相对含量高,细胞壁与液泡中的Na相对含量变化范围非常接近。在Na2CO3胁迫浓度低于0.1molL-1时,在相同胁迫强度下,K的相对含量高于Na的相对含量,使细胞质保持相对高的K/ Na比。而尽管向细胞壁和液泡分流了大量的Na,但是细胞质中的Na相对含量仍然随着Na2CO3胁迫强度的增加而增加,一方面证明星星草在Na2CO3胁迫下维持相对高的K/ Na比的能力是有一定限度的,另一方面暗示星星草作为盐生植物在盐碱环境中一定程度上Na可以部分地代替K而行使部分K的生理功能。  相似文献   

17.
《Flora》2014,209(3-4):185-190
Some salt-tolerant plants belonging to the Poaceae possess bicellular salt glands that excrete salt-containing water. To clarify the excretion process from the outer cell of the bicellular salt gland (cap cell), unwashed and washed fresh leaves of Rhodes grass (Chloris gayana Kunth), Poaceae, were cryo-fixed rapidly, and the surface fine structures of the leaves were observed by cryo-scanning electron microscopy with high resolution. The cuticle on the cap cell did not have any pores or signs of rupturing. The cuticle of the cap cells lacks the epicuticular waxes that cover most surfaces of leaf epidermis. After excreted droplets on the salt glands were completely removed by washing with water, re-excreted droplets were observed 3 h later. These findings indicate that the bicellular salt glands of Rhodes grass excrete salt-containing water continuously through the wax-free cuticle of the cap cell without disintegration of the cuticular structure.  相似文献   

18.
A better understanding of salt tolerance in plants might lead to the genetic engineering of crops that can grow in saline soils. Here we cloned and characterized plasma membrane and vacuolar Na?/H? antiporters of a monocotyledonous alkaline-tolerant halophyte, Puccinellia tenuiflora. The predicted amino acid sequence of the transporters were very similar to those of orthologs in monocotyledonous crops. Expression analysis showed that (1) NHA was more strongly induced by NaCl in the roots of P. tenuiflora while in rice it was rather induced in the shoots, suggesting that the role of NHA in salt excretion from the roots partly accounts for the difference in the tolerance of the two species, and that (2) NHXs were specifically induced by NaHCO? but not by NaCl in the roots of both species, suggesting that vacuolar-type Na?/H? antiporters play roles in pH regulation under alkaline salt conditions. Overexpression of the antiporters resulted in increased tolerance of shoots to NaCl and roots to NaHCO?. Overexpression lines exhibited a lower Na? content and a higher K? content in shoots under NaCl treatments, leading to a higher Na?/H? ratio.  相似文献   

19.
The young and expanded leaf micromorphology and ultrastructure of Eucalyptus grandis 2 E. urophylla juvenile plants, cultivated in greenhouse and field conditions, were analyzed by scanning and transmission electron microscopy. In greenhouse leaves epicuticular wax needles covered the abaxial and adaxial surfaces. On the adaxial surface, the needles form an atypical arrangement in lines, mainly over the anticlinal wall of epidermis cells. After plant transfer to field conditions, the organization of epicuticular wax was altered forming amorphous layers on the adaxial leaf surface, in contrast to the abaxial surface, which maintained the wax needle cover. In both culture conditions the lamellar cuticle formed on the young leaves surface disappeared during leaf enlargement. The ex vitro environment induced the development of hypostomatic leaves. The dorsiventral organization of greenhouse leaves was replaced by an isobilateral arrangement in field conditions with concomitant aerial space reduction. Results suggest that those structural changes may be some of the strategies to avoid excessive plant transpiration during Eucalyptus hybrid plants' acclimatization.  相似文献   

20.
Desert plants show specific mechanisms to thrive under prevailing harsh conditions. To study the survival mechanism(s) in native desert plant species, Lesser Cholistan desert in Pakistan was surveyed and two potential salt secretory grass species, Aeluropus lagopoides and Ochthochloa compressa , were selected from five saline sites. Both these grasses responded differentially to saline environments by showing specialized mechanisms of survival including excretion of toxic ions through trichomes, vesicular and glandular hairs through leaf surface. In A. lagopoides , salt tolerance was associated with excreted Na+ concentration through leaf surface and accumulation of useful ions like Ca2+ and K+ in the shoot. Contrarily, O. compressa excreted all the ions through leaves without discriminating among toxic or beneficial ions. Results suggested that A. lagopoides was more successfully adapted to saline desert environments than O. compressa by excretion of excessive toxic ions and retention of Ca2+ and K+ in the shoot. This appears to be an adaptive character of the former species to successfully thrive in harsh desert conditions.  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号