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1.
The conducting tissue structure of transverse and longitudinal sections was observed on leaves of Podocarpus and Nageia.Results showed:in Podocarpus leaves,there is only one midrib,the xylem tracheid of midrib vascular bundle is multi-form,transfusion tissue belongs to Cycas-type and transfusion tracheids are isodiametric,the accessory transfusion tracheids between palisade tissue and sponge tissue are developed;in Nageia leaves,there are plenty of parallel leaves,the xylem tracheids of each vein are relatively simple,transfusion tissue belongs to Taxus-type and transfusion tracheids are longer in longitudinal section than that in transverse section,the accessory transfusion tissue between palisade tissue and sponge tissue is absent.Considering other differences that in leaves of Podocarpus there are three resin ducts under vascular bundle of midrib,mesophyll cells are differentiated into palisade tissue and sponge tissue;in leaves of Nageia,there is only one resin duct under vascular bundle in each vein and no obvious differentiation in mesophyll cells,palisade tissue can be found on both sides,and sclereids can also be found in mesophyll tissue.The anatomical differences of leaf veins and mesophylls between Nageia and Podocarpus mentioned above support the viewpoint that Nageia and Podocarpus are two independent genera.  相似文献   

2.
The conducting tissue structure of transverse and longitudinal sections was observed on leaves of Podocarpus and Nageia.Results showed:in Podocarpus leaves,there is only one midrib,the xylem tracheid of midrib vascular bundle is multi-form,transfusion tissue belongs to Cycas-type and transfusion tracheids are isodiametric,the accessory transfusion tracheids between palisade tissue and sponge tissue are developed;in Nageia leaves,there are plenty of parallel leaves,the xylem tracheids of each vein are relatively simple,transfusion tissue belongs to Taxus-type and transfusion tracheids are longer in longitudinal section than that in transverse section,the accessory transfusion tissue between palisade tissue and sponge tissue is absent.Considering other differences that in leaves of Podocarpus there are three resin ducts under vascular bundle of midrib,mesophyll cells are differentiated into palisade tissue and sponge tissue;in leaves of Nageia,there is only one resin duct under vascular bundle in each vein and no obvious differentiation in mesophyll cells,palisade tissue can be found on both sides,and sclereids can also be found in mesophyll tissue.The anatomical differences of leaf veins and mesophylls between Nageia and Podocarpus mentioned above support the viewpoint that Nageia and Podocarpus are two independent genera.  相似文献   

3.
The leaf development of Podocarpus macrophyllus var.maki Endl.started from the leaf primordium formed by the cell division in shoot apical meristem.During the leaf development,three resin canals from the inferior part of vascular bundles firstly began to differentiate,then protoxylem in vascular bundles differentiated from adaxial side to abaxial side.Meanwhile,a layer of parenchyma cells from the inferior part of protoderm developed into the sclerenchyma,which played an important role in supporting young leaves.When xylem became mature basically,transfusion tissue,phloem and accessory transfusion tissue began to differentiate,so mesophyll tissue finally differentiated into developmental palisade cells and sponge cells.The thicker cuticle was formed in the lateral side of epidermal cells at the same time of differentiation and development for the inner structure of leaves.Therefore,the developmental palisade cells and the cuticle in the leaf structure of Podocarpus macrophyllus var.maki Endl.is greatly significant for photosynthesis and transpiration when it grows in arid and cold regions.  相似文献   

4.
The root of Alnus sibirica is rich in tissue type,Phloem fibers are obvious and Plasmodesmas are well developed.The number of primary xylem bunches are not stable,there are triarch,tetrarch and pentarech types.The perforation plate of vessel is scalariform,The rays types are radial in shape and unicellular in structure,In root nodule,cortex is the best developed structure,the stele is small.The root nodule is branched.In root nodule tissues,actinomyces proliferate luxuriently,the actinomyces body is in different shapes.  相似文献   

5.
The results of quantitative characters for anatomy in stems of three varieties tomatoes seedlings showed that the cell population between vascular bundle and epidermis, the cellular layers among vascular bundles and the cell population in an unit area (mm^2) of no vascular bundle areas were similar and there had small difference among three varieties. On the foundation of these studies, the developmental mechanism of tomato seedling stem was discussed.  相似文献   

6.
To study the effects of different concentrations of Abscisic Acid(ABA) on leaf tissue structure of Korla fragrant pear and lay the foundation for the cultivation and regulation of Korla fragrant pear. Using the paraffin section method, the leaf thickness, the epidermis thickness, the palisade tissue thickness and the sponge tissue thickness were measured; palisade spongy ratio, Cell Tightness(CT) and Cell Looseness(CL) were examined after treatments with exogenous ABA. Leaf thickness, leaf palisade spongy ratio and palisade tissue thickness increased significantly after exogenous ABA treatment compared with CK, while the effect on leaf epidermis was not obvious. The leaf thickness and palisade tissue thickness increased evidently after 70 mg · L~(-1) ABA treatment by 24.89% and 41.10%, respectively. The tissue structures of leaves were more compact, while CL was lower after 70 and 90 mg · L~(-1) ABA treatments. The effects of different concentrations of exogenous ABA could increase the leaf thickness, palisade tissue thickness of Korla fragrant pear and CT, reduced the thickness of spongy tissue and CL. Among those concentrations of exogenous ABA, the effect of spraying 70 mg · L~(-1) exogenous ABA was suitable for improving cold resistance of Korla fragrant pear.  相似文献   

7.
8.
This study attempts to examine the effects of salinity on leaf, stem, and nut of Pistacia vera (Ohady and Kaleh Ghochi cultivars) in order to characterize their anatomical structures with electron and light microscopy. A comparative study of the anatomy indicates a difference between the density of simple and glandular trichomes in leaf surface, deposit of wax, the thickness of leaf, the length of epidermal cells, palisade parenchyma cells, crystals in mesophyll, and the manner of compatibility to salinity. The results obtained in this research demonstrate that compatibility of Ohady cultivar is higher than Kaleh Ghochi and the degree of mechanical wounding depends on their development stages. In addition to results of previous studies which considered crop load as the main cause of fruit deformity. The present study indicates that, in spite of some reduction in total production of a tree, salinity decreases fruit deformity and to a high extent prevents the production of deformed fruit. Indeed, a remarkable reduction in production of deformed fruit will be yielded by selecting pistachio varieties which are resistant to salinity. Moreover, salinity increases the resistance of nuts to mechanical wounding. The results of this study suggest that in EC = 7.6, 12.6 deformity of nut is not related to crop load.  相似文献   

9.
This study aimed to analyze the relationship between nutrient elements K, Ca, Mg, Cu, Mn, Zn and Fe in tobacco-planting soils and tobacco leaves from six main tobacco-producing areas, and to investigate the influences of these elements on chemical composition and aroma components in tobacco leaves. Results showed that there were certain relationship between contents of nutrient elements in tobac- co-planting soils and contents of corresponding elements in tobacco leaves; various elements exhibited different influences on the aroma quality of flue-cured tobacco. Based on the actual situation of nutrient contents in soils from different tobacco- producing areas, contents of various elements in tobacco leaves should be regulat- ed by soil fertilization and foliar spraying, thereby improving the aroma quality of flue-cured tobacco.  相似文献   

10.
Increasing salinity of the groundwater is one of major challenges faced by agricultural sector in West Bank/Palestine. This study was carried out in the Lower Jordan Valley (LJV) under greenhouse field condition, where an area of 0.12 ha was irrigated with 3.5 dS/m magnetic treated water during the growing season 2012/2013. The results of this pilot project show that there are significant increases in the yield of red and yellow bell pepper of about 20% and 18% on fresh weight basis, respectively. Water use efficiency increased by 15% and an increase in shelf time of 7 d were also recorded. The chlorophyll content raised significantly in the leaves of treated plants compared to the controlled one by 2.5 mg/g. Bell pepper irrigated with magnetic water produces 37% more four champers than that of the controlled one. On the other hand, there were no clear significant effects on the height of the plant, number of fruits, distance between nods, size of fruits, number and thickness of walls and sugar contents. Applying visible/near infrared (VIS/N|R) spectroscopy test shows that it is possible to distinguish between treated and controlled bell pepper fruits. Multivariate data analysis (MVDA) method was used to test the classification of chemical elements in the fruit and it was found that treated and controlled fruit samples are divided into two groups according to their water treatment. An increase in all nutrient concentrations was found in fruits irrigated with magnetic treated water compared with the controlled one. Further testing is needed especially by involving other variables such as decreasing the volume of irrigated water and fertilizers.  相似文献   

11.
该研究对罗汉松属和竹柏属植物叶横切面和纵切面输导组织结构进行观察。结果表明:罗汉松属叶1条主脉,主脉维管束木质部管胞发达,转输组织为苏铁型,转输组织管胞等径,栅栏组织和海绵组织之间的副转输组织管胞发达;竹柏属叶多条平行叶脉,维管束木质部管胞相对不发达,转输组织为红豆杉型,转输组织管胞纵向伸长,栅栏组织和海绵组织之间不存在副转输组织。结合罗汉松属植物主脉维管束下面有3个树脂道,叶肉分化为栅栏组织和海绵组织,而竹柏属植物每个叶脉维管束下面有1个树脂道,叶肉分化不明显,两面都有栅栏组织,叶肉中还具有大量石细胞等特征,认为罗汉松属和竹柏属在叶脉、叶形态和结构方面存在明显差异,2个属分开是比较合理的。  相似文献   

12.
短叶罗汉松叶的发育起始于茎端侧面分生组织区细胞分裂形成的叶原基。在叶的发育过程中,维管束下方的3个树脂道最先分化发育,然后,维管束内的原生木质部由近轴面向远轴面分化发育,同时原表皮下的一层薄壁细胞发育形成厚壁组织纤维,起支持幼叶的作用。当木质部基本成熟时,转输组织和韧皮部以及副转输组织开始发育,最后,叶肉组织分化发育为发达的栅栏组织细胞和海绵组织细胞。在叶内部结构分化发育的同时,表皮细胞的外侧形成较厚的角质层。在短叶罗汉松叶的结构中,发达的栅栏组织和角质层对于其生长在干旱和寒冷地区进行光合作用和蒸腾作用具有极为重要的意义。  相似文献   

13.
大花君子兰营养器官的解剖学结构   总被引:1,自引:0,他引:1  
对大花君子兰营养器官根和叶片的解剖学结构观察结果显示:其不定根为肉质,具有发达的复表皮,复表皮最内层细胞具有分生组织细胞,向外分裂形成新的细胞;根尖组织分化属封闭型,根冠与表皮同源,根内皮层细胞具凯氏带加厚,初生本质部多原型。叶为等面叶,叶片上、下表皮细胞外壁均被有厚的角质层,气孔器的保卫细胞为肾形,具有发达的储水组织;叶肉细胞同型,无栅栏细胞和海绵组织的分化;平行脉序,维管束具有维管束鞘。  相似文献   

14.
西瓜营养器官解剖学研究   总被引:1,自引:0,他引:1  
西瓜的营养器官结构如下:(1)幼根由表皮、皮层和维管柱三部分组成,初生木质部为四原型;成熟根具有一定的次生结构,维管束为外韧型。(2)下胚轴的初生结构由表皮、皮层、维管束、髓和髓射线等构成,维管束为双韧型;次生生长时形成层主要存在于外韧皮部和木质部之间,为有限的次生生长。(3)地上茎的结构较复杂,初生结构中维管束排列近两轮;次生生长与下胚轴大致相似。(4)卷须的结构与茎的基本相似。(5)子叶与叶片均由表皮、皮层和叶脉三部分构成,叶片为典型的异面叶。  相似文献   

15.
硼对棉花叶片解剖结构的影响   总被引:3,自引:0,他引:3  
在土培条件下,研究了缺硼和硼中毒对棉花叶片解剖结构的影响。结果表明:缺硼真叶及子叶的叶脉维管束明显增长,输导组织严重受损,细胞畸形,细胞数显著增加,且叶片加厚,但栅栏组织所占比例及其细胞中的内含物减少并解体,导致总叶绿粒和线粒体降低,可能是减弱光介强度的重要原因之一。硼中毒仅影响叶缘及叶尖的解剖结构,表现为栅栏细胞叶绿粒减少,海绵细胞衰老坏死,表皮细胞排列紊乱、缺硼及硼中毒对解剖结构的变化与外观症状一致。  相似文献   

16.
利用光学显微镜观察比较了杂交景天(Sedum hybridum L.)和勘察加景天(Sedum kamtschaticum Fisch.)的叶表皮形态及解剖结构,研究表明:杂交景天和勘察加景天的叶肉细胞间隙大,通气组织发达,没有明显分化出栅栏组织和海绵组织;叶表皮具有发达的孔下室;维管组织较发达,叶肉细胞和维管组织中存在较多的储水能力强的粘液细胞,这些都是植物耐旱的关键。  相似文献   

17.
【目的】通过研究枳橙砧木对硼胁迫的反应,揭示缺硼对柑橘砧木细根根尖成熟区和中部功能叶解剖结构的影响。【方法】采用营养液的方式培养枳橙砧木幼苗,试验设置2个处理,分别为不施硼(-B)处理和施硼(硼酸含量为10 μmol·L-1,+B)处理。取枳橙砧木中上部的幼嫩叶片和细根根尖成熟区部分为观察材料,采用石蜡切片并结合透射电镜(TEM),研究缺硼对枳橙砧木解剖结构和亚细胞微观结构的影响。【结果】缺硼导致根部的皮层薄壁细胞数目减少且排列疏松紊乱、细胞变形破裂,细胞间隙增大;同时,细胞质出现解体并伴随多种细胞器消失,细胞壁厚度明显增加;而加硼处理的植株根部薄壁细胞的形态则表现正常,细胞大小均一,排列紧密,细胞间隙小;加硼处理的维管束细胞着色较深,形态正常,维管束的结构层次清晰,呈圆周状均匀分散在中央髓部周围。硼胁迫严重抑制了根部维管束发育,使其分化不明显、细胞体积小且排列无规则。缺硼的叶片纵切面加厚且不均匀,海绵组织细胞变形破裂,细胞间出现大的空缺,细胞数目多且体积大,使得海绵组织在叶肉中所占的比例明显增加;加硼处理的叶片纵切面各处厚度均一,表皮细胞形状规则排列紧密,栅栏组织细胞呈长圆柱形,细胞单层垂直分布表皮细胞之下,细胞排列整齐紧密;栅栏组织下面的海绵组织细胞结构完整,排列疏松,细胞间形成大小均匀的气腔。另外,缺硼导致叶片细胞中积累较多淀粉粒,叶片可溶性糖与淀粉含量比加硼时分别提高35.3%和66.7%,而加硼处理的叶片细胞中则没有观察到有明显的淀粉粒存在;缺硼叶片的维管束中薄壁细胞出现变形、破裂等现象。【结论】缺硼破坏细胞内部结构,造成细胞壁加厚,叶片细胞内淀粉粒积累加剧;影响叶片中海绵组织细胞形态大小,细胞出现不正常增生,从而抑制砧木根尖及叶片中维管束的发育。  相似文献   

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