地构叶和广东地构叶基因组大小测定

以水稻为外标,采用流式细胞仪测定2种地构叶属植物地构叶和广东地构叶的基因组大小。结果表明:地构叶的基因组大小(2C DNA含量)平均为(0.81±0.02)pg,广东地构叶的基因组大小(2C DNA含量)平均为(0.85±0.02)pg。

地构叶化学成分的研究

从地构叶(Speranskia tuberculata)地上部分分离得到9个化合物,根据其理化性质及波谱特征被鉴定为软脂酸、β-谷甾醇、三十烷醇、香草酸、阿魏酸、对香豆酸、loliolide,胸腺嘧啶和尿嘧啶。香草酸和阿魏酸有较好的抗氧化活性,以上化合物均为首次从该植物获得。

地构叶黄酮类化合物的分离鉴定

从地构叶的地上部分分离得到6个黄酮类化合物，根据其性质及波谱特征分别被鉴定为香叶木素，5，7，3'-30H-OCH3黄酮（1），木犀草素5，7，3'4'-4OH黄酮（2），5，7－4'-三羟基二氢黄酮－7－O－β－D－（4″－对香豆酰）－吡喃葡萄糖苷（3），5，7，4'－三羟基二氢黄酮－7－O－β－D（3″，对香豆酰）－吡喃葡萄糖苷（4），穗花杉双黄酮（5），木犀草素－7－O－芸香糖苷（6），所有的化合物均为首次从地构叶得到，化合物3为新化合物，命名为地构苷。

构叶的降压作用及其机制初步分析

实验表明构叶浸膏剂(2.5g,5g/kg)灌胃,能剂量依赖性地降低自发性高血压大鼠血压。并观察到在大鼠肛尾肌,构叶总甙(0.1％,0.3％)能使去氧肾上腺素累积量效曲线右移,同时最大效应下降。用L—B公式证明去氧肾上腺素的解离常数未变,说明构叶总甙具有非竞争性α受体阻断作用。该作用可能与构叶的降压效应有关。

蒙药地构叶对小鼠抗炎镇痛作用研究

地构叶作为一种来源广泛的镇痛抗炎中药,具有广泛的药用价值。为探讨蒙药地构叶镇痛、抗炎药理作用,将小鼠随机分三组,分别为模型组、阿司匹林组、地构叶组,每组各8只。灌胃给药,进行镇痛、抗炎实验。镇痛作用:与模型组比较,地构叶水提取液镇痛作用明显(P<0.05);抗炎作用:与模型组比较,地构叶水提取液抗炎作用显著(P<0.05),与阿司匹林组相近。结果可知,对于正常小鼠,因物理和化学等多种因素引起的疼痛,地构叶均有抗炎镇痛作用,效果显著(P<0.05)。其数据为进一步研究地构叶的作用机制提供了实验依据。

构叶制剂抗喘作用和急性毒性研究

构叶醇提剂及水提剂能明显拮抗组胺引起的豚鼠实验性哮喘。离体豚鼠气管实验表明,构叶水提剂能部分或完全拮抗组胺或乙酰胆碱的兴奋作用。小鼠急性毒性实验表明,构叶300 mg/10g体重,一日2次,连用3日,未见任何不良反应,说明其毒性甚小。

基于最大熵模型和地理信息系统地构叶生态适宜性研究

目的探讨地构叶在我国的生态适宜性区划。方法利用最大熵模型和ArcGIS10.5软件对实地调查的35个地构叶分布信息数据、中国数字植物标本馆获取的172条地构叶分布信息及55种生态因子数据进行运算分析。结果调查显示,影响地构叶生长的7个主要生态因子为11月降水量、3月温度、9月降水量、温度季节性变化标准差、土壤含黏土量最干季节降水量、最干季节均温,甘肃东南部、陕西南部、山西南部、河北西南部、山东中部为地构叶的主要分布区。结论应用此方法研究地构叶生态适宜性区划具有较好的精确度和可信度,研究结果与实际分布相契合,可为地构叶野生资源勘测和保护地区的选择提供参考依据。

构叶制剂抗炎止血效应研究

本实验证明构叶对小鼠纤维组织增生有明显抑制作用(琼脂法);并具有显著止血作用,能使小鼠凝血时间(玻片法和毛细玻管法)和出血时间(断尾法)显著缩短。

构叶的生药学研究

目的通过对构叶的生药学研究,为构叶的开发利用、质量标准的制定及生药学方面的研究提供依据。方法依据形态学特征对构叶进行原植物形态、性状特征、显微特征鉴别,运用薄层色谱、紫外光谱法对构叶进行理化特征鉴定。结果构属植物构叶的药材性状、显微特征、理化特征(薄层色谱,紫外吸收光谱)与同属植物小构叶鉴别特点有明显不同。结论研究结果可作为构叶生药质量标准制定的依据。

高产小麦品种蘖叶构型动态模式的探索

为阐述高产的小麦蘖叶构型特征,并验证了具有这种蘖叶构型小麦品种的高产性,对郑麦7698、周麦18和矮抗58的蘖叶动态及其特征进行分析。结果表明,高产小麦蘖叶建构过程中,分蘖以冬前低位蘖为主,春生高位蘖少且不拔节;小麦生育前期冠层上部叶片直立,冠层透光性好,下部叶片面积大且持绿期长,在灌浆中后期叶片仍能保持较好的直立性。这种蘖叶构型分蘖冗余小,光和养分资源能高效利用,同时冠层透光性好,群体光合同化能力可以得到充分发挥,进而易于实现高产。该蘖叶构型在密植条件下的优势更为突出,有助于解决生产中农民大播量种植进而造成倒伏减产的问题。

普通野生稻-长喙毛茛泽泻-柳叶箬混作种群的竞争效应

以正交实验探讨了普通野生稻、长喙毛茛泽泻和柳叶箬 3因子各 5个种植密度水平对各种群的影响。结果表明 ,混作对 3种植物均有不利影响 ,初始密度越大 ,影响越大。各种群对于来自种间的竞争是敏感的 ,对来自种内竞争的影响也不可忽视。3个因子中 ,普通野生稻因子作用最大 ,柳叶箬因子次之。从测定的项目看 ,在不同的种植水平上 ,每一种群的无性繁殖率和单株生物量明显受到自身和其它因子的影响。初始密度越大 ,无性繁殖率越小。普通野生稻和柳叶箬种群的单枝生物量随着初始密度的增加而提高 ,但长喙毛茛泽泻种群单株生物量则随着初始密度的增加而降低。比起普通野生稻和柳叶箬种群 ,长喙毛茛泽泻种群在光合份额和有性生殖份额方面对密度的变化要敏感得多 ,其无性小株死亡率也随着初始密度的增加而上升。总之 ,柳叶箬种群有最强的竞争能力 ,普通野生稻种群次之 ,长喙毛茛泽泻种群竞争能力最弱 ,在竞争中处于不利的地位 ,当混作实验种群经一个生长季节后 。

Embryogenesis,Germination,Structure and Cotyledon Dimorphism of Zea mays Embryo

A series of new cognitions on the morphogenesis of maize ( Zea mays L.) embryo have been obtained with scanning electron microscopy and semi-thin section techniques. 1. The proembryo. The proembryo from zygotic cell divisions may be divided into three parts: proper, hypoblast and suspensor. The suspensor is short and small, and only exists transiently. As to the hypoblast there is a growth belt, which promotes elongation of the hypoblast. Eventually the upper portion of the hypoblast contributes to the formation of the coleorhiza and the remainder dries up, sticking to the end of the coleorhiza. 2. The maize embryo possesses dorsiventrality and cotyledon dimorphism. During early proembryo stage, the dorsiventrality appears in the proper of the embryo. On the ventral side, the cells are small with dense cytoplasm and few vacuoles. On the dorsal side, the cells are larger with lower cytoplasmic density and have more vacuoles. During later proembryo stage, the proper develops into two parts: the ventrum and the dorsurn. The ventrum rises up from the center of the ventral side. The dorsurn is composed of the marginal area of the ventral side and the whole dorsal side of the proper. During young embryo development, the ventrum differentiates into the coleoptile, apical meristem, hypocotyl, radicle and the main part of the coleorhiza. What is more important, the emergence of coleoptile primordium and radicular initials occur at the axis of the proper, then the coleoptile primordium expands from its two ends toward left and right to form a ring, and the endogenous radicular initials expand in all directions to form a conical radicular tip. All these morphogenetic activities of the ventrum follow a bilateral symmetrical pattern. The dorsurn forms the scutellum. primordium. Then the scutellum primordium, expands rapidly toward the left, right, front and back, while thickening itself, so as to make all components originating from the ventrum become hidden in the longitudinal groove of the scutellum. Lastly, the left and right lateral scales emerge from the edges of the longitudinal groove and expand toward the central line of the axis. As a consequence, morphologically, the bilateral symmetry of the ventral side of the embryo is revealed entirely. Morphogenetically, the coleoptile primordium and apical meristem in maize are similar to the coleoptile (apical cotyledon) and apex formation of the nice embryo, so the coleoptile of the maize embryo can also be considered as an apical cotyledon. The scutellum is a lateral cotyledon. These dimorphic cotyledons of the maize embryo originate from the dorsiventrality of the proper. 3. The true morphological structure of the maize embryo is recognized and its developmental stages are established. A maize embryo is a hypocotyl, in which the apical part is the shoot apex (or plumule) with the coleoptile, the central part consists mainly of the hypocotyl with a lateral cotyledon (scutellum), and the basal part is the radicle with coleorhiza. The left and right lateral scales derived from the scutellum overlap at the ventral side, leaving only two little pores at both ends of the seam from which the coleoptile and coleorhiza can be seen. The four sequential stages of maize embryonic development are as follows: (1) proembryo, stage. This stage covers a period from zygotic cell division to the appearance of the dorsum and ventrum. (2) ventrum rapid differentiation stage. (3) scutellum rapid expansion stage. (4) lateral scale development stage (or embryonic envelope formation stage). 4. To obtain a median longitudinal section perpendicular to the ventral surface is crucial for recognizing the genuine morphological structure of the maize embryo.

Optimization models of stand structure and selective cutting cycle for large diameter trees of broadleaved forest in Changbai Mountain

The optimum models of harvesting yield and net profits of large diameter trees for broadleaved forest were developed, of which include matrix growth sub-model, harvesting cost and wood price sub-models, based on the data from Hongshi Forestry Bureau, in Changbai Mountain region, Jilin Province, China. The data were measured in 232 permanent sample plots. With the data of permanent sample plots, the parameters of transition probability and ingrowth models were estimated, and some models were compared and partly modified. During the simulation of stand structure, four factors such as largest diameter residual tree （LDT）, the ratio of the number of trees in a given diameter class to those in the next larger diameter class （q）, residual basal area （RBA） and selective cutting cycle （C） were considered. The simulation results showed that the optimum stand structure parameters for large diameter trees are as follows： q is 1.2, LDT is 46cm, RBA is larger than 26 m^2 and selective cutting cycle time （C） is between 10 and 20 years.

Effect of soil moisture gradient on structure of broad-leaved/Korean pine forest in Changbai Mountain

A 112 m×8 m sample pot which includes 14 sub-plots was set up along the slope in Hongshi Forestry Farm of Baihe Forestry Bureau (127°55′E, 42°30′ N), Jilin Province in August 2002. Community structure, soil moisture contents at 0–10 cm and 10–20 cm in depth, water content of litter as well as the contents of C, N and P of litter, living leaves and branches in the broad-leaved/Korean pine (Pinus korraiensis) forest were measured in each sub-plot on different slope positions. The analytical results showed that there existed an obvious soil moisture gradient along the slope: upper slope <middle slope< lower slope. The difference in soil moisture contents on different positions of slope led to a change of the stand structure of the braod-leaved/Korean pine forest. The proportion ofQuercus mongolica gradually increased with the decrease of soil moisture content and that of other major tree species in the broad-leaved/Korean pine forest gradually decreased or disappeared. The dynamic of soil moisture contents in the litter layer was as same as that in mineral soils. The decomposition rates of the litter on different slope positions were different and the dry weights of existent litter varied significantly. The soil nutrients in the litter on the lower slope was richer than that on the upper slope due to the different stand structure on the different slope positions. The moisture content and nutrient contents of soil had effects on the composition, decomposition, and the nutrient release of litter, thus affecting stands growth and stand structure and finally leading to the change of ecosystem. Key words Soil moisture gradient - nutrient - Stand structure - Broad-leaved/Korean pine forest CLC number S718.5 Document code A Foundation item: This study was supported by the NKBRSF (G1999043407-1), Tackle Key Problem of Science and technology of China (2001BA510B-07), Knowledge Innovation Program of the Chinese Academy of Sciences (KZCX2-406, SCXZD0101), NKTRDP (2001BA510B-07. 2002BA516A20).Biography: WANG Yan (1970-), female, Ph. D, associate professorResponsible editor: Song Funan

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.

Effect of Different Spacing on Structure of Fluecure Tobacco Leaf Grade

[Objective] This study was conducted to investigate the effects of different plant spacing on tobacco grade structure, growth stages, agronomic traits, yield and chemical composition under fixed row spacing. [Method] Under fixed row spacing （120 cm）, 4 treatments were designed （40, 50, 60 and 45 cm）. The growth stages, agronomic traits, economic traits and chemical composition of flue-cured tobacco leaves were compared and analyzed. [Result] with the increase of plant spacing, there were no significant differences in the emergence time of growth stages be- tween different treatment groups before resettling stage, and the resettling stage ap- peared 1-2 d in advance. At different tobacco growth stages, the changing trends of tobacco agronomic traits with the change of plant spacing were different. [Conclusion] With the increase of plant spacing, the planting density of tobacco de- creased, and the nicotine content increased; and the yield of tobacco decreased continuously, while the quality was improved, but when the plant spacing was im- proved to certain degree, the quality of tobacco also decreased, and at the plant spacing of 50 cm, the output value of tobacco was the highest.

Relationship Between Leaf Structure and Aloin Content in Six Species of Aloe L.

The leaf structure, content and the storage location of aloin in the leaves of six species of Aloe L. were studied by means of semi-thin section, high performance liquid chromatography (HPLC) and fluorescent microscope. Results showed that all leaves consisted of epidermis, chlorenchyma, aquiferous tissue and vascular bundles. The leaves had the xeromorphic characteristics, including thickened epidermal cell wall, thickened cuticle, sunken stomata and well-developed aquiferous tissue. With the exception of thus, there were remarkable differences in leaf structure among the six species. The chlorenchyma cells were similar to palisade tissues in Aloe arborescens Mill. and A. mutabilis Pillans, but isodiametric in A. vera L., A. vera L. var. chinensis Berg., A. saponaria Hawer and A. greenii Bali. A. arborescens, A. mutabilis, A. very and A. vera var. chinensis included large parenchymatous cells at the vascular bundles, whereas no such cells were observed at the vascular bundles of A. saponaria and A. greenii. In A. arborescens, A. mutabilis and A. vera, the aquiferous tissue sheaths were present and composed of a layer of small parenchymatous cells without chloroplasts around the aquiferous tissue. While there were no aquiferous tissue sheaths in A. vera var. chinensis, A. saponaria and A. greenii. The HPLC revealed that the content of aloin was high in A. arborescens, low in A. vera, and very low in A. saponaria among the six species. The fluorescent microscopy showed that the yellow-green globule only appeared in the large parenchymatous cells of vascular bundles, vascular bundle sheath and aquiferous tissue sheath, but not in the chlorenchyma and aquiferous tissue. Consequently, the large parenchymatous cells of vascular bundles, vascular bundle sheath and aquiferous tissue sheath were the storage location of aloin. They were positively correlated with the content of aloin.

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.