植物叶表皮制片技术的改进

[目的]对传统的次氯酸钠法制备叶表皮制片技术进行改进,使材料脱水后仍保持平展状态。[方法]试验材料脱水前用甘油蛋白胶做黏贴处理。[结果]黏贴处理过的材料不发生卷曲。[结论]在植物叶表皮制片过程中,用甘油蛋白胶做黏贴处理,可有效防止试验材料脱水后遇二甲苯发生卷曲现象,并能使剥离的叶表皮更加平整。     

连翘花器官与叶表皮的扫描电镜观察

[目的]观察连翘花器官和叶表皮的形态特征,为连翘优良品种的引种栽培与分类学研究提供基础资料。[方法]将连翘的花器官和叶的上下表皮分别粘附在样品杯的双面胶上,然后在扫描电镜下观察、拍照和测量。[结果]花粉为长球形,具有3孔沟,外壁表面具网状纹饰;柱头2叉分枝,属于干柱头;花柱表皮气孔为无规则型;叶上、下表皮角质层纹饰不同,且均有腺体分布,未见表皮毛,气孔器仅分布在下表皮。[结论]该方法准确、可靠,为连翘优良品种的引种栽培、形态分类学研究提供了理论依据。     

中国粗榧叶气孔器及其解剖结构特征

运用扫描电镜对中国粗榧叶片的上下表面进行扫描照相,运用石蜡制片技术、普通显微照相观察其解剖结构特征.结果表明,中国粗榧叶上表面光滑,无气孔分布;气孔器主要分布于叶下表面中脉两侧,规则排列,形成两条白色气孔器带,气孔器密度为72.48个/mm2,中脉无气孔器分布.     

菵草属及其近缘属叶下表皮微形态的研究

为了探讨菵草属的系统学位置,采用次氯酸钠离析法制作叶表皮装片,用光学显微镜对菵草属及其近缘属植物的叶下表皮微形态特征进行观察。结果显示:菵草属及其近缘属,燕麦族和早熟禾族植物的叶下表皮均为典型的狐茅型,具有较高的一致性。脉间长细胞大多为长筒形,细胞壁大多平直,少数波状弯曲;脉间区短细胞稀少或常见;脉上都分布有刺细胞或短细胞;气孔器大多为2~3列;副卫细胞为平行形,少数为低圆屋顶形。叶表皮微形态显示菵草属不应划入虎尾草族,早熟禾族和燕麦族没有明显的界限,支持早熟禾族和燕麦族合并为广义的早熟禾族,菵草属归为广义的早熟禾族。     

香蕉叶表面特征及浸润性机理研究

【目的】研究香蕉树冠层不同时期蕉叶的正、反面润湿行为,以期为农药雾滴在蕉叶表面滞留调控机制提供依据。【方法】采用接触角测量仪表征蕉叶表面的静态润湿性能;利用高速摄像机记录液滴在蕉叶表面的动态润湿行为;使用场发射扫描电镜对蕉叶表面进行微观形貌观察获取表面结构信息,并借助傅立叶红外光谱仪分析其表面化学成分;基于Wenzel和Cassie润湿理论构建蕉叶表面微观结构模型,建立润湿方程阐述其润湿机理。【结果】扫描电镜发现蕉叶正面呈现微米-纳米级双层复合结构,在微米级突起结构上布满了纳米级乳突结构,分布为4.6个/μm²,条状突起宽度为(16.03±3.48)μm,乳突平均直径为(0.116±0.068)μm,蕉叶背面微米级条状突起结构尺寸大于正面,宽度为(74.25±9.80)μm,纳米级结构上呈现出网状突起,宽度为(2.35±0.49)μm,蕉叶背面的润湿性普遍大于正面的;在不同生长时期的蕉叶中,剑叶正面表现出亲水性,静态接触角(Contact angle,CA)为71.46°±6.02°,而其他时期的蕉叶正、反面均表现出弱疏水性,表明嫩叶正面具有更强的润湿和铺展能力;...     

Cytokeratins in the canine epidermis

The purpose of this study was to characterize the cytokeratins (CKs) present in the clinically normal skin of dogs. Skin samples from five German shepherds, five Boxers, five Cocker spaniels, five Yorkshire terriers and five mongrels were examined biochemically (using gel electrophoresis and western blotting) and immunohistochemically (using a alkaline phosphatase anti-alkaline phosphatase technique). Results indicated that the canine epidermis expressed the cytokeratins 1, 5, 6, 10/11, 14 and 16. There were no consistent differences in CK expression between the examined breeds with the exception of an individual polymorphism in CK1 and CK10/11. Immunohistochemical studies showed CK 14 labelling of the basal cell layer whereas CK10/11 staining was seen in the suprabasal cell layer of epidermis. Surprisingly, expression of CK6, known as 'stress' cytokeratin, was demonstrated in all epidermal samples. These results indicate that there is a striking consistency of cytokeratin expression in different breeds which should be useful in the investigation and characterization of canine skin diseases.     

Immunohistochemical localization of androgen and oestrogen receptors in canine hair follicles

Skin biopsies from seven different body sites were obtained from 21 dogs of different breeds (short, normal, long hair), which were presented for euthanasia. Commercially available polyclonal antibodies were used for the immunohistochemical detection of androgen and oestrogen receptors. Both receptors showed a similar distribution in canine skin, with specific intranuclear staining. In the epidermis, the percentage of androgen receptor (AR)-positive cells, but not that of oestrogen receptor (ER)-positive cells, was significantly higher in samples from the thorax and the flank. In the dermal papilla, the percentage of ER-positive (but not AR-positive) cells was significantly lower in biopsies from the flank. No significant difference was found for both receptors between the locations in the outer root sheath, among the three different hair types, between sex and between intact and castrated dogs.     

Spray retention, foliar uptake and translocation of glufosinate and glyphosate in Ambrosia artemisiifolia

Ambrosia artemisiifolia plants exhibit stomata on both leaf surfaces and three types of trichomes: (i) small (<50 μm) spherical or ovoid, (ii) medium‐sized (50–100 μm) and (iii) long (100–200 μm) and sharp. Only the long and sharp trichomes were stained with AgNO₃, indicating the presence of hydrophilic domains. Epicuticular waxes appeared amorphous, consistent with high levels of spray retention. Glufosinate was readily taken up by A. artemisiifolia leaves, with maximum uptake of >80% of the applied label, and half maximum uptake being reached within 6 h. The foliar uptake of glyphosate was nearly complete and half of it was attained after 3 h. Glufosinate and glyphosate were ambimobile and their translocation out of the treated leaves amounted to 13–16% and 11–15% of the absorbed radioactive label respectively. Glufosinate was mainly directed to the apical developing tissues, with less amounts reaching the tissues below the treated leaves. Glyphosate was directed towards the sink tissues (apical developing tissues and roots). The sensitivity of A. artemisiifolia to glufosinate and glyphosate can be explained by high spray retention, rapid and important foliar uptake, and appreciable migration out of the parts of the plant hit by the spray.     

六种前胡属植物叶表皮形态学研究

采用光学显微镜对前胡属6种植物的叶表皮进行了观察, 从显微镜观察的结果表明：前胡（P.praeruptori）的叶片气孔仅存在于下表皮,红前胡(P.rubricaule),松潘前胡(P.songpanens),长前胡(P.turgeniifolii),滇西前胡(P.delavayi)和刺尖前胡(P.elegans)的叶片两面表皮均有气孔;气孔类型均为不规则形;上下表皮细胞形状为多边形或不规则形;垂周壁式样可区分为近平直、浅波状和深波状;气孔密度和气孔指数在属内种间,尤其是在近缘种间有所差异,可以作为鉴别特征。六种前胡属植物的叶表皮形态均为首次报道。     

六种前胡属植物叶表皮形态学研究

采用光学显微镜对前胡属6种植物的叶表皮进行了观察, 从显微镜观察的结果表明：前胡（P.praeruptori）的叶片气孔仅存在于下表皮,红前胡(P.rubricaule),松潘前胡(P.songpanens),长前胡(P.turgeniifolii),滇西前胡(P.delavayi)和刺尖前胡(P.elegans)的叶片两面表皮均有气孔;气孔类型均为不规则形;上下表皮细胞形状为多边形或不规则形;垂周壁式样可区分为近平直、浅波状和深波状;气孔密度和气孔指数在属内种间,尤其是在近缘种间有所差异,可以作为鉴别特征。六种前胡属植物的叶表皮形态均为首次报道。