蛇足石杉的形态学及不同光照处理下气孔特征的研究

对蛇足石杉的形态学特征进行了重新描述,并对不同光照处理下蛇足石杉叶片的气孔特征进行比较。结果表明：在一定范围内,随着环境中光照强度的增加,气孔长度和宽度、单个气孔面积、气孔密度及气孔总面积都呈增加的趋势。当光照强度超过某一阈值时其气孔指数和气孔密度仍呈增加的趋势,但气孔长度、宽度和单个气孔面积呈变小趋势。小而密的气孔是其适应旱生环境的表现,表明其具有一定的生态适应能力,但进行人工栽培时应避免光照过强。     

河西地区几种中生植物的蒸腾和传导率与叶内外环境的关系

用LI-1600稳态气孔仪,测定了河西地区分布较广的五种木本植物的蒸腾和传导率及环境因子。只要光照不低于气孔开启所需的强度,植物蒸腾率最高点之前的高低变化与叶温上升的速率无关,而仅与每一时刻叶温高低密切相关。在种内,蒸腾率大致随叶的厚度和单位叶面积的栅栏组织表面积的增大而提高。但种间则无此相关性。同一样本叶的上下表面蒸腾率之比与其气孔数之比相对应,而种间则毫无关系。环境条件大致相同情况下,二白杨(Populus kansuensis)全天蒸腾量为78.2gH2O·dm-2,沙枣(Elaeagnus angustifolia)为40,4gH2O·dm-2。分别是箭杆杨(P.nigra var.thevestina)的2.5和1.3倍。同一灌溉条件下,梨光杏(Prunus armeniaca var.glabra)为26.7gH2O·dm-2,比毛杏(P.armeniaca var.ansu)高0.6倍。     

Field Studies of the Wheat Stomata Resistance Influenced by Soil Water Content

Concurrent observations of soil water potential and leaf stomata diffusion resistance were made on two, plots of wheat grown at Datun Agro-ecological Experimental Station in Beijing under two different soil water conditions. These data were further complemented by weather and physiological observation. In this paper, we mainly analysed the influence of soil water potential on the status of wheat leaf stomatal resistance. The results indicate that: (1) there is a obvious influence of soil water potential on the status of wheat leaf stomata under normal conditions and (2) there is a different upper and lower epidermis stomata of wheat leaf respond to the soil water potential. The lower epidermis stomata are more sensitive to soil water potential than upper epidermis one. (3) There is a linear relationship between the ratio of lower and upper epidermis stomata resistance and soil water potential in root layer, according to this we can diagnose the degree of wheat water deficit.     

Changes of Leaf Morphological, Anatomical Structure and Carbon Isotope Ratio with the Height of the Wangtian Tree （Parashorea chinensis） in Xishuangbanna, China

Leaf morphological and anatomical structure and carbon isotope ratio （δ^13C） change with increasing tree height. To determine how tree height affects leaf characteristics, we measured the leaf area, specific leaf mass （ratio of leaf mass to leaf area [LMA]）, thickness of the total leaf, cuticle, epidermis, palisade and sponge mesophyll, stomata traits and δ^13C at different heights of Parashorea chinensis with methods of light and scanning electron microscopy （SEM） and isotope-ratio mass spectrometry. The correlation and stepwise regression between tree height and leaf structure traits were carried out with SPSS software. The results showed that leaf structures and δ^13C differed significantly along the tree height gradient. The leaf area, thickness of sponge mesophyll and size of stomata decreased with increasing height, whereas the thickness of lamina, palisade mesophyll, epidermis, and cuticle, ratios of palisade to spongy thickness, density of stomata and vascular bundles, LMA and δ^13C increased with tree height. Tree height showed a significant relationship with all leaf indices and the most significant relationship was with epidermis thickness, leaf area, cuticle thickness, δ^13C. The δ^13C value showed a significantly positive relationship with LMA （R = 0.934）. Our results supported the hypothesis that the leaf structures exhibited more xeromorphic characteristics with the increasing gradient of tree height.     

The Electrical Analogy Analysis and Simulation Testing of the Relationship Between Net Photosynthetic Rate and Stomatal Conductance

The hypothesis about the linear relationship between net photosynthetic rate and stomatal conductance, which had formed the basis of the empirical model proposed by Ball et al, was analyzed by analogy with electrical resistance and simulation testing. The results showed that the relationship between stomatal conductance and net photosynthetic rate was non-linear, but approaches a linear one when there was a large the boundary layer conductance of leaf. In addition, the way in which the ratio of CO2 concentrations in and out of the stomata changes with light and the influence of boundary layer conductance on the ratio had also been simulated.     

Imbibition of Swietenia macrophylla (Meliaceae) seeds: the role of stomata

BACKGROUND AND AIMS: The occurrence of stomata in seed coats is uncommon and there is limited information about their function(s). The aim of this study was to verify the distribution of stomata in seed coats of Swietenia macrophylla and to relate it to the imbibition process and aspects of the structure of the outer integument layers. METHODS: For the structural and ultrastructural studies, the seeds were processed using the usual techniques and studied under light and scanning electron microscopes. Histochemical tests were employed to identify the cell wall composition in the different seed coat portions. To assess the role of the stomata in the imbibition, non-impervious seeds were compared with partially impervious ones, in which only the embryo, median or hilar regions were left free. Further, the apoplastic pathway marker was employed to confirm the role of the stomata as sites of water passage during imbibition. KEY RESULTS: A positive relationship was observed between seed coat thickness and stomata density. The stomata were devoid of movement, with a large pore. They occurred in large numbers in the embryo region and extended with lower frequency towards the wing. Imbibition rates were related to stomata density, suggesting that the stomata act as preferential sites for water entry in the S. macrophylla seeds. CONCLUSIONS: At maturity, the stomata in the seed coat play a significant role in seed imbibition. The data may also infer that these permanently opened stomata have an important role in gas exchange during seed development, aiding embryo respiration.     

净光合速率与气孔导度相互关系的电学类比分析和模拟研究

对Ｂａｌｌ等的气孔模型所依据的实验事实之一（净光合速率与气孔导度呈线性关系）作了只考虑各阻力与总通量之间关系的电学类比分析和模拟检验。从电学类比分析得到的关系式可以看出,净光合速率与气孔导度的关系是非线性的,只有当叶片的边界层导度比较大时,两者的关系才接近线性。模拟得到的结论也是一样的。另外还模拟了气孔内外ＣＯ２ 浓度之比随光强的变化以及边界层导度的影响,模拟结果可以解释已有的实验结果     

不同海拔高度泡沙参叶片形态研究

对不同海拔高度的泡沙参叶表形态、气孔特征进行了观察,比较了不同海拔高度对泡沙参叶片生态适应的影响。结果表明：泡沙参叶表皮角质层较厚,被有大量表皮毛和蜡质颗粒,海拔越高越明显;泡沙参气孔复体类型均为不规则型,气孔保卫细胞角质层较厚,气孔口较小,气孔密度与气孔大小成反比,并且气孔大小随海拔升高而减小,气孔密度随海拔升高而增大,是一种抗旱适应的表现。     

中国葡萄属植物叶片气孔特征的研究

对起源于中国的葡萄属(Vitis L.)20个种或变种叶片气孔特性进行了观察研究。结果表明:气孔纵径对葡萄属种的分类有较大的价值;气孔比密度(叶片上所有气孔复合体面积与叶片面积之比)与叶片大小呈极显著正相关;气孔密度与气孔纵径呈极显著负相关;所有观察种类的叶片气孔类型均为不规则型。     

Stomata in some species of genus <Emphasis Type="Italic">Arum</Emphasis> from the Eastern Slavonia and Baranya region

Types and the number of stomata in the following Arum species: Arum italicum Mill., Arum maculatum var. maculatum L. and Arum maculatum var. immaculatum L., Arum alpinum var. pannonicum Terpo. and Arum alpinum var. intermedium Schur. in three different locations in Zablaće, Normanci and Bilje were investigated. The most prevalent stomata type at both upper and lower epidermis for each Arum species was mostly stomata type paracytic, followed by hexacytic, tetracytic or brachyparacytic as far as locality is concerned. Helicocytic type was more prevalent in Arum alpinum var. pannonicum Terpo. and Arum alpinum var. intermedium Schur. at Bilje. Other stomata types were very rare. A striking regularity in the occurrence of stomata types was not found within a single species. Some stomata types, however, were found either at adaxial or abaxial epidermis or were not present at all. The number of stomata per square mm varied from 25 to 651. A statistically significant difference in the number of stomata per square mm at upper and lower epidermis among Arum species was determined in locations Zablaće and Normanci, whereas no statistically significant differences were found in location Bilje.     

The dependence of stomatal closure on protein synthesis

Seven different inhibitors of the synthesis of protein and RNA, all of which are found to delay the senescence of detached oat leaves in darkness, also cause the opening of the stomata in the dark. The concentration ranges for activity on the two processes agree closely. Four other compounds of similar effects on RNA and protein synthesis, but which are inactive on senescence, correspondingly fail to open the stomata. This not only strengthens the relationship between stomatal closure and senescence, but—more important—provides strong evidence that continued protein synthesis is necessary to keep foliar stomata closed.     

妊娠和激素干预对豚鼠卵巢囊淋巴孔的影响

In order to study the influence of pregnancy and hormone on the lymphatic stomata of guinea pig's ovary bursa, the lymphatic stomata of ovary bursa were observed during pregnancy and by using exogenous hormone, including serum gonadotrophin (PMSG) combined with human chorionic gonadotropin (HCG) to promote ovulation and androgen to inhibit the ovary. Then the lymphatic stomata in the inner layer of ovary bursa and their absorption functions were observed with scanning electron microscope (SEM) and trypan blue as a tracer respectively. The lymphatic stomata were also counted by the Elescope computer image processing system. We found that the quantity of tracer absorbed by the lymphatic stomata of ovary bursa in pregnant group was more than that in ovulation-promoted group, and least in the androgen-treated group, which had statistical significance between each couples of them (P < 0.05). The opening area of the lymphatic stomata in pregnant, ovulation-promoted and androgen-treated groups were 189.9 +/- 48.7 micron 2/1000 micron 2, 104.4 +/- 31.2 micron 2/1000 micron 2 and 40.5 +/- 18.7 micron 2/1000 micron 2 respectively, which had remarkable statistical difference between each couples (P < 0.01). Under SEM observation, the secretory granules in ciliated columnar epithelium were less in pregnant group than the other two, while both the secretory granules and the cilium were most active in ovulation-promoted group. The results indicated that both the openings and absorption functions of the lymphatic stomata in guinea pig's ovary bursa could be affected by pregnancy and exogenous homone. There existed relationship between ovary function and the regulation of the lymphatic stomata in ovary bursa.     

Electrical Currents at the Leaf Surface of Commelina communis and their Relationship to Stomatal Activity

A vibrating probe was used to detect and measure electricalcurrents at the surface of excised leaves and isolated leafepidermis from Commelina commnunis. Currents of up to 4.0 µAcm^–2 moving out from the leaf surface were observed whenthe stomata were open. When the stomata were almost closed nocurrent was detected and when they were fully closed a smallinwardly directed current was observed. There appeared to bea linear relationship between current and stomatal aperture.The current was stimulated by fusicoccin and eliminated by increasingthe external pH suggesting that it was brought about by a flowof H⁺ from the leaf surface. Key words: Electrical currents, leaves, stomata, vibrating probe     

Stomatal frequency of Quercus myrsinaefolia grown under different irradiances

Stomatal and epidermal cell frequencies and leaf area were measured in leaves of Quercus myrsinaefolia grown in the field under different relative photon flux density (PFD), which was the ratio of integrated PFD at the leaf surface to that at an open site. Leaf area showed a linear relationship with the relative PFD. Stomatal and epidermal cell frequencies increased with increasing relative PFD. Numbers of stomata and epidermal cells per leaf, and stomatal index (ratio of stomatal number to epidermal cell number) increased with increasing relative PFD.     

白刺叶片气孔特征对人工模拟降雨的响应

以荒漠生态系统典型植物白刺(Nitraria tangutorum Bobr)叶片为研究对象,利用数码图像显微镜处理系统,研究了不同人工模拟增雨处理下的白刺叶片气孔密度及形态特征的变化情况。结果表明,荒漠植物固有特征决定了白刺叶片下表皮气孔密度大于上表皮,上表皮、下表皮气孔密度对增雨响应差异不显著(P0.05)。增雨处理上表皮、下表皮气孔密度与对照差异显著(P0.05)。相同增雨季节,50%处理下叶片气孔密度高于100%处理;不同增雨季节,气孔密度对生长季后期增雨响应更明显。白刺叶表皮气孔分布遵循"一细胞间隔(one cell spacing rule)"法则。增雨后叶片上表皮和下表皮气孔长度、宽度均有不同程度的增加,气孔形态特征对100%处理的响应较50%处理更为明显,且生长季后期增雨对叶片气孔形态特征的影响更大。     

水杨酸对黄瓜子叶表皮气孔开度的调节作用

以黄瓜品种中农203(Cucumis sativus L.cv.Zhongnong 203)幼苗为试材,采用SA溶液根部施用和子叶表皮浸泡两种方式,显微观测了不同外源水杨酸(Salicylic acid,SA)溶液处理对其子叶表皮气孔开度的影响,以探讨SA与气孔运动的关系.结果表明:SA子叶表皮浸泡或根部施用后,气孔运动的趋势是随着SA浓度增加而孔径逐渐变小,且SA磷酸缓冲液的作用效果与SA水溶液相似.随着处理时间的延长,气孔开度逐渐变小,且气孔开度与SA处理时间达极显著(r=-0.962**)或显著(r=-0.914*)负相关.溶液低pH值,增强了SA对气孔开度的抑制作用,且SA浓度越高作用越明显;0.1 mmol/L SA处理后,pH为8、7、6溶液的气孔开度抑制率分别为90.2%、93.8%和96.3%,即SA溶液对气孔开度的抑制率随着溶液pH降低而升高.可见,外源SA能够促进气孔关闭,其作用随着SA浓度升高、处理时间延长和溶液pH值降低而增强,相对于磷酸缓冲液,以蒸馏水作为溶剂的SA溶液促进气孔关闭的作用更大.     

Growth and photosynthesis of Japanese flowering cherry under simulated microgravity conditions.

The photosynthetic rate, the leaf characteristics related to photosynthesis, such as the chlorophyll content, chlorophyll a/b ratio and density of the stomata, the leaf area and the dry weight in seedlings of Japanese flowering cherry grown under normal gravity and simulated microgravity conditions were examined. No significant differences were found in the photosynthetic rates between the two conditions. Moreover, leaf characteristics such as the chlorophyll content, chlorophyll a/b ratio and density of the stomata in the seedlings grown under the simulated microgravity condition were not affected. However, the photosynthetic product of the whole seedling under the simulated microgravity condition increased compared with the control due to its leaf area increase. The results suggest that dynamic gravitational stimulus controls the partitioning of the products of photosynthesis.     

适应不同光环境小蜡叶片气孔导度、气孔开度和气孔密度的时空变化

对生长在强光环境和弱光环境小蜡叶片的气孔参数测定发现 :气孔导度和气孔开度在 4个取样部位存在异质性分布。气孔导度和气孔开度经回归分析呈线性、指数或多项式分布。统计分析表明 :强光下的叶片气孔导度和气孔开度的相关性明显高于弱光环境叶片的数值。无论强光环境还是弱光环境下的叶片 ,在取样部位编号为1和 3,其气孔导度和气孔开度均存在显著的线性关系。弱光环境下叶片的气孔密度要远低于强光环境下的叶片。强光环境下叶片对变化环境的敏感性要大于弱光环境下的叶片 ,这可能与强光环境叶片具有较高的气孔密度有关。     

Stomatal frequency of Quercus myrsinaefolia grown under different irradiances

Stomatal and epidermal cell frequencies and leaf area were measured in leaves of Quercus myrsinaefolia grown in the field under different relative photon flux density (PFD), which was the ratio of integrated PFD at the leaf surface to that at an open site. Leaf area showed a linear relationship with the relative PFD. Stomatal and epidermal cell frequencies increased with increasing relative PFD. Numbers of stomata and epidermal cells per leaf, and stomatal index (ratio of stomatal number to epidermal cell number) increased with increasing relative PFD. This revised version was published online in June 2006 with corrections to the Cover Date.     

Stomatal characteristics during micropropagation of Wrightia tomentosa

A deviation from usually found characteristics of stomata in Wrightia tomentosa was noted during in vitro propagation. Increase in stomatal frequency in leaves of plants grown in vitro was observed with 29.4 % malformed stomata. The stomata were spherical, wide open, did not close in detached leaves even after 3 h. The leaves exhibited 93.4 % total water loss during 3-h period. Stomatal frequency, percentage of malformed stomata and rate of water loss declined in subsequent rooting phase. Nevertheless, for high survival rate plantlets were hardened under gradually decreasing air humidity either in partially opened glass bottles containing Soilrite™ moistened with 1/4 Murashige and Skoog nutrients or in pots covered with polyethylene bags. The stomatal characteristics of hardened plants were comparable to seedlings. Survival rate was more than 95 %.