Comparative Study on the Structural and Moisture Characteristics of Leaf from the Plantlets of Three Types of Ornamental Lilium brownii

[ Objective] The study was to compare the structural and moisture characteristics of leaf from the plantlets of three types of omamental lily（ Lilium brownii）. [ Method ] The paraffin sections of leaves of tested lily varieties were prepared and then observed under microscope, and the stomatal characteristics and moisture characteristics of tested lily varieties were measured. I Resaltl All the three ornamental lily varieties show isobilateral leaf, single layer of epicuticula and lower epidermis, and no obvious differentiation of palisade tissue and spongy tissue; their stomata distribute in lower epidermis, and the guard cells are dumbbell-shaped; all of these matedais present high moisture. For the leaf sick- ness, midrib sickness and mesophyll tissue sickness, the order was determined to be oriental lily 〉 Lilium/ongiflorum 〉 Asian lily; of the three types of ornamental lily, Ulium Iongiflorum has the largest stomatai aperture and Asian lily has the smallest; focusing the water potential and moisture, the turn was Asian lily 〉 oriental lily 〉 Lilium Iong＇fflorum. [ Condusion] The study may facilitate the artificial regulation of the growth conditions of the plantlets of ornamental lily.

STRUCTURAL RESPONSE OF SOYBEAN LEAF TO ELEVATED CO_2 CONCENTRATION

The effects of CO 2 concentration on the morphological and anatomical characters of soybean (Glycine max) leaf were investigated by means of light microscopy and SEM.It was noticed that exomorphology did not show dramatic change,while stomatal density decreased with increasing CO 2 concentration.Under SEM,no epicuticular wax was observed on both abaxial and adaxial sides of the control group as well as on adaxial side of the treatment group.However,leaf surface of abaxial side was noticed to be densely covered with microasterisk epicuticular wax when they were exposed to CO 2 enriched environment.The epicuticular wax deposition was present in equal abundance on both stomatal and nonstomatal areas.Furthermore,leaf thickness increased significantly due largely to the origin of an extra layer of palisade in the treatment group.The results confirmed that CO 2 enrichment might enhance cell division and induce greater quantity of epicuticular wax.

Research Progress on Leaf Anatomical Structures of Plants Under Drought Stress

Plants usually suffer drought stress during their growth process. As the photosynthetic activity center of plants, the leaf is the most sensitive organ under drought stress. In order to support the research on drought resistance of higher plants, this study reviewed the adaptation response and damage performance of epidermal structure, palisade tissue and spongy tissue, thickness, veins and stomata of plant leaves under drought stress.

Effect of TYLCV Infection on Leaf Anatomical Structure and Protective Enzyme System of Tomato

[Objective] The aim was to study the effect of tomato yellow leaf curl virus （TYLCV） infection on leaf anatomical structure and protective enzyme system of tomato. [Method] The anatomical structure of infected and healthy leaves of tomato were observed and compared by using paraffin section method. The activity changes of SOD, POD and CAT in the infected leaves of tomato were determined. [ Result] The results revealed that there were some differences in anatomical structure between healthy and infected leaves. Some cells of infected leaves were damaged so that the leaves curled and became yellow, which affected the normal function of organs. Compared with control, enzyme activities in the tomato plants infected by TYLCV were enhanced at the early periods and higher than that in control, then started to decline at the middle and late periods but lower than that in control.[ Conclusion] After infection by TYLCV, the leaf anatomical structure of tomato was changed greatly and the protective enzyme system was damaged severely, and affected the normal physJological metabolic functions of tissues and organs in tomato in further.

Effects of Salt Stress on Anatomical Structure of Leaves of Malus sieversii and Malus robusta

[Objective] This study was conducted to compare leaf anatomical structure of Malus sieversii and M. robusta under different salt concentration levels to determine their tolerance to salt and thus to provide rootstock materials for apple production in salinized soil in Southern Xinjiang. [Method] The experiment was conducted with M. sieversii and M. robusta as test materials. Salt stress was simulated using 8 g/L of NaCI solution, and Hoagland nutrient solution was used instead of NaCI solution as control group （CK）. Samples were collected on the 20^th d of treatment, sliced through paraffin processing. The prepared paraffin sections of M. sieversii and M. robusta were then observed under a light microscope for anatomical structures of leaf, upper epidermis, lower epidermis, palisade tissue and spongy tissue. [Result] Compared with the control, the leaf, upper epidermis, lower epidermis and spongy tissue of M. sieversii and M. robusta under salt stress were thickened at different degrees, while the thickness of the palisade tissue was decreased. Moreover, high salt concentration caused severer damage to the cell structure of M. sieversii than to that of M. robusta, as M. robusta cells maintained better structural integrity. [Conclusion] M. robusta has higher adaptability to salt stress than M. sieversii.

The Structure of Oryza Embryos and Their Dimorphic Cotyledons

It has been generally held in botany that Oryza sativa L. is a monocotyledon. Based on studies of rice embryo development we confirmed that rice embryo has two dimorphic cotyledons rather than just one cotyledon. In the present study we attempt to know if the morphology of embryos in other species of Oryza differs from O. sativa and if these embryos have dimorphic cotyledon. Two types of embryo structures were observed in 22 species and/or subspecies of genus Oryza under the scanning electron microscope. Type 1, the O.sativa type, which is characterized by ventral scale and lateral scales, was found in 16 species. Type 2, the O. meyeriana (Zoll. et Mor. ex Steud.) Baill. ssp. tuberculata W. C. Wu et Y. G. Lu, G. C. Wang type, with no ventral scale and lateral scales, was found in 6 species and subspecies. The embryogenic process of O.sativa and O.meyeriana sub. tuberculata showed that the scutellum primordium, coleorhiza primordium, coleoptile primordium and shoot apical meristem directly differentiate from proembryo. The former two later develop into the embryo envelope, which is the outside cotyledon; the coleoptile primordium develops into the coleoptile with the shape of inverted empty cone surrounding and covering the growth cone, which is the apical cotyledon. Both types of rice embryos have dimorphic cotyledons. The structural difference between them is that the scutellum primordium of the young embryo in type 2 does not differentiate ventral scale and lateral scales while the embryo of type 1 does. The dimorphic cotyledons of embryo of Oryza plants originate from the dorsiventrality of proembryo.

Effects of PP333 and Exogenous ABA on Leaf Tissue Structure of Armeniaca vulgaris ‘Luntaibaixing'

[Objective] This study aimed to investigate the effects of PP333 and ex- ogenous ABA on the growth and development of Armeniaca vulgaris ＇Luntaibaixing＇ so as to provide a theoretical basis for the growth regulation of Luntaibaixing in cultivation and management. [Method} Different concentrations of PP333 and ABA were sprayed to Luntaibaixing during the rapid growth period of fresh treetops. The technology of paraffin section was used to measure the thickness of leaf, upper epidermis, lower epidermis, palisade tissue and sponge tissue. The thickness ratio of palisade tissue to sponge tissue, tightness degree of leaf tissue structure （CTR） and loose degree of leaf tissue structure （SR） were calculated and the differences in leaf tissue structure were analyzed. [Result] The thickness of leaf and palisade tissue both increased significantly after treated by PP333. At the treatment concen- tration of 1 000 mg/L, the thickness ratio of palisade tissue to sponge tissue and the value of CTR were highest, while the thickness of sponge tissue and the value of SR were lowest. The thickness of leaf and palisade tissue also increased after treated by ABA, and it increased most greatly at the ABA concentration of 60 mg/L compared with CK. At the treatment concentration of 60 rag/L, the thickness ratio of palisade tissue to sponge tissue and the value of CTR were the highest, while the thickness of sponge tissue and the value of SR were the lowest. [Conclusion] ABA and PP333 treatment increased the leaf thickness, palisade tissue thickness, pal- isade tissue to sponge tissue thickness ratio and CRT value, but reduced the sponge tissue thickness and SR value of Luntaibaixing.

Study on Adaptability of Datura stramonium and Datura stramonium var. tatual to Temperature

This study was conducted to investigate the temperature adaptability of Datura stramonium and D. stramonium var. tatual. Under 4 temperature levels,plantgrowth and pigment concentrations in leaves and stems were determined, and leaf anatomic structures of D. stramonium var. tatual and D. stramonium were analyzed. The results showed that the palisade tissue thickness/sponge tissue thickness,stomatal density and stomatal index values of D. stramonium var. tatual were significantly greater than D. stramonium; the chlorophyll content/carotenoid content in leaves of D. stramonium var. tatual increased at first and decreased then, while no regularity was found in leaves of D. stramonium; and the contents of anthocyanin,flavonoids, and total phenols in stems of D. stramonium var. tatual were significantly higher than those in stems of D. stramonium. The temperature adaptability of D.stramonium var. tatual is stronger than that of D. stramonium.

Preliminary Study on Electron Crystallography of 27 kD LHC-Ⅱ Complex from Cucumber

Cucumber ( Cucumis sativus L.) LHC_Ⅱ complex, which consists of only one subunit (27 kD), was isolated and purified. 2_D crystallization was performed by batch method. The crystal is 0.7 μm×1.0 μm, and diffracts to 30 ?. The projection map of the negatively stained two_dimensional crystal of LHC_Ⅱ complex shows that the crystal has p3 symmetry, lattice constant 15.4 nm×15.4 nm, which is different from the LHC_Ⅱ of spinach (Spinacia oleracea L.) and pea (Pisum satium L.). A continuous tomographic tilt series, containing 12 projections from the two_dimensional crystal was subjected to 3_D reconstruction. The 3_D model represents that LHC_Ⅱ complex consists of 6 monomers. These trimer and dimer interactions build up the six member ring.

运用建构主义思想进行生物教学

众所周知,教学是师生的双边活动.然而,长期以来传统教育只注重教师的"教",忽视学生的"学",致使教学成了教师的"单边活动",学生在其中充当的只是"配角",只有被动接受的"义务",没有自主探究的权力.本来是一群群天真活泼、聪明可爱的孩子,经过几年的"正统"教育培养、训练后,个个都变成了缺乏个性,像一个模子刻出来的"书呆子".人们不仅要问,这样的教学能培养出现代化人才吗?痛定思痛,现在该是花大力气改变这种局面的时候了.因此,我在初一生物第一册(上)《叶片结构》的教学中,大胆采用建构主义教学,变传统的"单向传授"为"师生共建";变"以教师为中心"为"以学生为主体";变教学为"导学"、"帮学"、"促学".

Influence of Different Root Temperature Treatment on Microstructure of Tomato Leaves

Following the study on effects of different root temperature treatments on growth and stomata of tomato plants under high temperature in summer, the influence of different root temperature treatments on microstructure of tomato leaves was studied in depth in this paper. The tomato plants were cultured with circulating nutrient solutions. Under three different root temperature treatments [（23±1）, （28±1）, （33±1）℃], the microstructure of tomato leaves were observed and measured with paraffin section method. The results showed that with the increase of root temperature, the thickness, palisade tissue thickness, spongy tissue thickness of tomato leaves all decreased, but the epidermis thickness and palisade tissue thickness to spongy tissue thickness ratio increased. Therefore, increased root temperature led to drought stress to tomato plants, and in order to adapt to the hot and drought environment, tomato plants changed their structural characteristics.

Influence of Copper Stress on Ultra-structure of Wheat Seedlings

Transmission Electron Microscope (TEM) Technology was used to investigate the effect of 25,100 and 200 mg/kg copper on ultra-structure of root tip and leaf blade of wheat. Result showed that serious damage was found with Copper of 25,100 and 200 mg/kg. Plasmolysis,concentrated cytoplasm,chloroplast inflation,lamellar structure disturbance,capsule disappearance and disintegration,mitochondria structures ambiguity and vacuolization were all symptoms under Cu stress. There were positive correlation between concentration of coper stress and the degree of injury,and the degree of injury of copper were different in different organelles. Mitochondria were the most sensitive organelles,and there was patient difference in the same organelles of different parts.

Protection of ultrastructure in chilling-stressed banana leaves by salicylic acid

Objective： Chilling tolerance of salicylic acid （SA） in banana seedlings （Musa acuminata cv., Williams 8818） was investigated by changes in ultrastructure in this study. Methods： Light and electron microscope observation. Results： Pretreatment with 0.5 mmol/L SA under normal growth conditions （30/22 ℃） by foliar spray and root irrigation resulted in many changes in ultrastructure of banana cells, such as cells separation from palisade parenchymas, the appearance of crevices in cell walls, the swelling of grana and stromal thylakoids, and a reduction in the number of starch granules. These results implied that SA treatment at 30/22 ℃ could be a type of stress. During 3 d of exposure to 7 ℃ chilling stress under low light, however, cell ultrastructure of SA-pretreated banana seedlings showed less deterioration than those of control seedlings （distilled water-pretreated）. Conclusion： SA could provide some protection for cell structure of chilling-stressed banana seedling.

Anatomy of Different Ages of Streblus asper Leaves and Their Drought Resistance

The leaf thickness, stratum corneum thickness, epidermis thickness, palisade tissue thickness and sponge tissue thickness of Streblus asper leaves at different ages were observed by using paraffin section technology and optical microscopic observation to explore the anatomic adaptive response mechanism to drought stress, also to provide a theoretical basis for S. asper introduction. The results showed that under drought stress, various parts of S. asper leaf anatomy showed some characteristics adapted to water environment. Leaf palisade tissue cells became shorter, increasing from 1-2 layers to 2-3 layers; sponge cells were arranged in neat and compact long column shape, and the upper and down epidermis were thickened. The upper and down epidermis produced more trichomes to resist stress. After rehydration, leaf porosity increased and trichomes had a corresponding reduction. The principal component analysis showed that the stratum corneum thickness, leaf thickness and palisade were available to describe the impact of stress and rehydration on different ages of S. asper leaf anatomy. Under drought stress, S. asper leaf stratum corneum thickness and leaf thickness increased and leaves returned to normal after rehydration. Middle and top leaves were better than basal leaves in response to drought stress sensitivity.

Influence of Shape and Size of Threshing Frame and Tobacco Grade on Leaf Strip Structure

This paper focused on the influence of the shape and size of threshing frames as well as the grades of tobacco leaves on the structure of threshed leaves.The testing tobacco leaves all came from the hilly ecological region of Nanling and belonged to burnt sweet,alcoholic sweet and scent category.The comprehensive evaluating value S was taken as the test index.Results showed that,without considering the influence of tobacco grade on leaf structure,the shapes of first-stage thresher five-link frames were all hexagons,and the combination with the sizes of 3.5,3.0,3.5,3.0,3.0 inches had the highest evaluating value S of 2.49.For tobacco grade C2FH,the shapes of first-stage thresher five-link frames were also hexagons,and the evaluating value S reached the highest value of 3.40 with sizes of 3.5,3.0,3.5,3.0,3.0 inches.Comprehensive analysis showed that:3.0 inch frame performed better in controlling the percentage of large-sized strips than 3.5 inch frame did;rhombic frames were better than hexagon frames in reducing the breakage rate of tobacco leaves;different shapes or sizes of nonadjacent two-link frames can help to improve the threshing quality.

Analysis of Turbulence Structure in the Stirred Tank with a Deep Hollow Blade Disc Turbine by Time-resolved PIV

The turbulence structure in the stirred tank with a deep hollow blade(semi-ellispe) disc turbine(HEDT) was investigated by using time-resolved particle image velocimetry(TRPIV) and traditional PIV.In the stirred tank,the turbulence generated by blade passage includes the periodic components and the random turbulent ones.Traditional PIV with angle-resolved measurement and TRPIV with wavelet analysis were both used to obtain the random turbulent kinetic energy as a comparison.The wavelet analysis method was successfully used in this work to separate the random turbulent kinetic energy.The distributions of the periodic kinetic energy and the random turbulent kinetic energy were obtained.In the impeller region,the averaged random turbulent kinetic energy was about 2.6 times of the averaged periodic one.The kinetic energies at different wavelet scales from a6 to d1 were also calculated and compared.TRPIV was used to record the sequence of instantaneous velocity in the impeller stream.The evolution of the impeller stream was observed clearly and the sequence of the vorticity field was also obtained for the identification of vortices.The slope of the energy spectrum was approximately-5/3 in high frequency representing the existence of inertial subrange and some isotropic properties in stirred tank.From the power spectral density(PSD) ,one peak existed evidently,which was located at f0(blade passage frequency) generated by the blade passage.

Monitoring of Wind Turbine Blades Based on Dual-Tree Complex Wavelet Transform

Structural health monitoring(SHM)in-service is very important for wind turbine system.Because the central wavelength of a fiber Bragg grating(FBG)sensor changes linearly with strain or temperature,FBG-based sensors are easily applied to structural tests.Therefore,the monitoring of wind turbine blades by FBG sensors is proposed.The method is experimentally proved to be feasible.Five FBG sensors were set along the blade length in order to measure distributed strain.However,environmental or measurement noise may cover the structural signals.Dual-tree complex wavelet transform(DT-CWT)is suggested to wipe off the noise.The experimental studies indicate that the tested strain fluctuate distinctly as one of the blades is broken.The rotation period is about 1 s at the given working condition.However,the period is about 0.3 s if all the wind blades are in good conditions.Therefore,strain monitoring by FBG sensors could predict damage of a wind turbine blade system.Moreover,the studies indicate that monitoring of one blade is adequate to diagnose the status of a wind generator.

Response of Leaf Tissue Structure to PP333 in Korla Fragrant Pear

[Objective] This study was performed to explore the effect of different concentrations of PP333 on leaf tissue structure of Korla fragrant pear and to lay the foundation for the cultivation and regulation of Korla fragrant pear. [Method] The leaf tissues treated with different concentrations of PP333 were dehydrated with al- cohol, embedded in paraffin and sliced into 10-μm slices. The thicknesses of leaf blade, upper epidermis, lower epidermis, palisade tissue and sponge tissue were measured, and the ratio of palisade to spongy layer thickness, cell tightness （CT） and cell looseness （CL） were calculated. [Result] The thickness of leaf blade, the ratio of palisade to sponge layer thickness and the thickness of palisade layer were all significantly increased after treatment with PP333. Treatment with 2 500 mg/L PP333 showed no obvious effect on the thickness of leaf epidermis, but increased the thicknesses of leaf blade and palisade tissue. Leaf CL was the highest in the treatment of 1 500 mg/L PP333. [Conclusion] PP333 can increase the leaf thickness, palisade tissue thickness and CT, reduce spongy tissue thickness and CL of Korla fragrant pear. Additionally, 1 500 mg/L was the optimal concentration for the application of PP333 to improve the cold resistance of Koda fragrant pear.

Leaf Vein Density： A Possible Role as Cooling System

The study of leaves and their architecture evolution is important for understanding the fluid dynamics of water movement in /eaves. Recent studies have shown how these systems can be involved in the performance of physiological aspects, which are directly connected with the density of the vascular network and stomata per unit of surface area. The vein architecture, beyond being essential for a mechanical support of the leaf, can also play a crucial role in the efficiency of the photosynthesis. The aim of the present work was to highlight the possible role of leaves vein network as cooling system. The results support the hypothesis that the vascular system of grape leaves is correlated with leaf temperature.

Structural Changes of Lignified Tissues from Sugarcane Leaves Induced by Smut （Sporisorium scitamineum） Virulence Factors

Sugarcane leaf shows the classical arrangement of cells, which defines a C4 species. Vascular bundles consist of xylem, phloem and fibres, surrounded by an outer layer ofsclereids and an inner ring of stone cells associated with the phloem. Some sclereids located below and above the vascular bundles act as docking cells and connect the vascular bundle to the internal surfaces of upper and lower layers of the epidermis. A compact mass ofsclereids occupies the total internal volume of the leaf edge. Neither docking cells nor the internal mass of sclereids in the edge were markedly coloured by phloroglucinol, indicating the absence of lignin in their cell walls. However, such staining indicated that fibres of the vascular bundle and the external layer of sclereids were strongly lignified. Incubation of leaf discs with an virulence factors produced by the pathogen Sporisorium scitamineum increased the thickness of the lignified cell walls of sclereids as well as the mid and small xylem vessels, as a possible mechanical defence response to the potential entry of the pathogen. This mechanism was mainly revealed for the resistant cv. Mayari 55-14, whereas lignification decreased for the susceptible cv. B 42231.