三只羊岩溶峰丛洼地果-药复合栽培模式研究

岩溶峰丛洼地的耕地可分为3种类型:洼底平地、带状阶梯地和高坡石穴地。传统的玉米+黄豆种植模式在三种类型耕地上的产值均很低,需要调整品种结构,改革种植模式。该文报道了基于三种耕地特点的四种果-药复合种植试验,即沙田柚+绞股蓝、大果枇杷+射干+扶芳藤、无核黄皮+射干+扶芳藤、四月桃+金银花。初步结果显示,四种模式均可大幅度提高耕地的产值,可作为岩溶峰丛洼地地区生态农业可持续发展的重要模式。     

典型峰丛洼地耕地、聚落及其与喀斯特石漠化的相互关系——案例研究

喀斯特石漠化,近年来已成为研究热点和引起国家层面重视,但当前研究并没揭示岩溶山地土地为什么会发生石漠化这一现象的本质,没有阐明岩溶山地农户为什么要进行不合理活动。通过典型案例研究从理论上解释岩溶山地农户为什么要进行不合理活动这个问题,以从本质上揭示石漠化发生的机理。为此,在贵州选择了6个典型峰丛洼地,采用2010年的10 m分辨率ALOS影像作为数据源,比较了6种不同的峰丛洼地组合地形中的耕地资源分布、聚落特征和石漠化发育情况。结果表明,6个研究点耕地和聚落数量、分布和石漠化的面积和分布存在一定的相互关系,这些相互关系可阐明土地承载力较低情形、土地承载力中等情形和土地承载力较高情形石漠化发生的过程;发现严重的石漠化只能出现在土地承载力低、人口压力大的区域,并据此进一步总结了峰丛洼地区石漠化形成的理论模型。从理论上揭示了峰丛洼地区土地承载力和人口压力是否协调决定了峰丛洼地区的生态质量状况,有助于从本质上认识石漠化的发生机理和指导石漠化的治理。     

扶芳藤组织培养再生体系的建立

扶芳藤茎段比叶盘易产生不定芽;4种基因型中,圆瓣扶芳藤的不定芽再生频率远远高于其他3种;MS 6-BA 2.0mg·L-1是圆瓣扶芳藤不定芽诱导的最适培养基;低温处理10 d可显著提高不定芽的再生频率;暗培养对扶芳藤再生影响不大;扶芳藤诱导不定芽的最适pH范围在5.8～6.2之间;最适琼脂浓度为0.6%.     

喀斯特峰丛洼地不同土地利用方式土壤水分对降水特征的响应

为了明确喀斯特峰丛洼地不同土地利用类型土壤水分对降水的响应, 采用定位观测法, 选择顺坡种植桂牧1号、顺坡种植玉米、封育、刈割除根、火烧、刈割6种喀斯特峰丛洼地最典型的土地利用方式, 分析了这6种土地利用方式下土壤水分动态变化。结果表明: 研究区2011—2013年的降水量可分为枯水年(2011年)、丰水年(2012年)和平水年(2013年)三种降水年型。枯水年土壤水分年均含量表现为种植桂牧1号>封育>刈割>火烧>刈割除根>种植玉米, 平水年和丰水年均表现为封育>刈割>种植桂牧1号>火烧>刈割除根>种植玉米。封育和桂牧1号土地利用方式在各降水年型下均具有较高的水分含量, 而种植玉米土壤含水量则最低, 其次为刈割除根。降水年型对土壤水分变异系数的影响表现为枯水年>丰水年>平水年的趋势。不同土地利用方式在枯水年、丰水年和平水年三种降水年型中, 土壤水分变化趋势各有特点, 主要受近期降水和土壤蒸发的影响。封育和桂牧1号土壤水分含量高, 两种土地利用方式能显著改善土壤水分状况, 积蓄一定的水分。     

三只羊岩溶峰丛洼地桃树优质高产栽培技术研究

在广西三只羊岩溶峰丛洼地进行幼龄期桃树作物套种、施肥以及疏果等栽培技术的对比试验。结果表明,套种黄豆能明显促进桃树基茎和主枝直径的增长,套种玉米则抑制桃树基茎和主枝直径的增长;混施猪粪水和磷肥的桃树其果实品质明显优于混施羊粪和磷肥以及牛粪和磷肥的桃树的果实;同时,中等疏果强度,即保留枝条上桃果间距14~18cm,可获最大种植效益,桃果重量增加50.3%,桃树的产值提高52.9%。     

桂西峰丛岩溶区的环境特点及农业生态系统优化设计

桂西岩溶峰丛山区生态系统功能脆弱、抗干扰能力低 ,面临严重的生态危机 ,急需修复和重建。以生态学的原理与方法为指导 ,进行土地利用的优化设计 ,调整农村产业结构 ,通过全面封育与先锋群落的构建 ,实行乔灌藤草优化配置、生态防护林体系与特色农林产品基地建设结合 ,恢复良好的森林植被 ,涵养表层岩溶水 ,改善生存环境 ,进行不同地貌部位和岩溶地质背景下适生植物合理布局 ,是峰丛岩溶区生态恢复重建的基本步骤。     

滇东南岩溶地貌下土壤物理性质对油茶地蜂种群数量的影响

【目的】揭示滇东南岩溶地貌下土壤物理性质对油茶地蜂Andrena camellia Wu种群数量的影响。【方法】测定并比较江西宜春丘陵地貌下具油茶地蜂"筑巢适生区"和无"筑巢适生区"的油茶林地,以及云南文山岩溶地貌下"峰丛"和"洼地"中油茶林地的土壤硬度值、容重、含水量、温度和颗粒组成,并测定四类型样地中油茶地蜂巢穴密度和访花多度。【结果】滇东南岩溶地貌中峰丛和洼地样地土壤硬度、容重和温度显著高于江西宜春具"筑巢适应区"样地,但土壤含水量显著低于江西宜春具"筑巢适应区"样地。未检测到不同林地间土壤颗粒组成百分率差异。滇东南岩溶地貌中峰丛和洼地样地油茶地蜂巢穴密度和访花多度显著低于江西宜春具"筑巢适生区"的样地。土壤物理性质影响油茶地蜂巢穴密度。土壤硬度可作为重要指标,用于快速、简便检测油茶林下土壤是否适应油茶地蜂筑巢。滇东南油茶样地土壤硬度系统测定结果表明,岩溶地貌典型样地土壤硬度高于适应油茶地蜂筑巢的土壤硬度阀值(2.50 MPa)。【结论】滇东南岩溶地貌下油茶林地土壤物理性质不适应油茶地蜂筑巢。     

喀斯特峰丛洼地石漠化治理自然地域分区

峰丛洼地是我国西南地区面积最大的喀斯特地貌类型区,水热资源相对较好,由于其较高的景观异质性,该区面临着石漠化治理投入与分区粗放、治理技术与模式区域针对性不强等问题,亟需开展面向石漠化治理的喀斯特峰丛洼地自然地域分区。基于修正的地质图将峰丛洼地区划分成碎屑岩为主的非喀斯特区和碳酸盐岩为主的喀斯特区,依据气候分异特征将喀斯特区划分为滇东南桂西南西南季风非典型峰丛洼地区和东亚季风典型峰丛洼地区,进一步依据大地貌部位及微地貌特征将东亚季风典型峰丛洼地区细分为黔西南高原面浅碟型锥峰洼地区、黔南桂北大斜坡北部漏斗型锥峰洼地区、桂中大斜坡南部漏斗型锥塔峰洼地区和桂南丘陵浅碟型锥塔峰洼谷区等亚区。分区结果表明各分区自然地域特征鲜明:碎屑岩为主的非喀斯特区坡缓土厚,人口压力相对舒缓;西南季风非典型峰丛洼地区受气候影响显著,地貌形态以常态山为主;桂中大斜坡南部漏斗型锥塔峰洼地区重度、极重度石漠化问题突出,但削减快、治理成效显著;黔西南高原面浅碟型锥峰洼地区人地矛盾最为尖锐,石漠化问题严重;黔南桂北大斜坡北部漏斗型锥峰洼地区石漠化比例相对较低、喀斯特景观资源丰富;桂南丘陵浅碟型锥塔峰洼谷地区水热资源最为充沛、人地关系相对缓和。面向石漠化治理的喀斯特峰丛洼地自然地域分区明确了分区的自然与社会经济条件差异,有助于提升石漠化治理的区域针对性和可持续性。     

弄拉典型峰丛岩溶区青冈栎叶片形态特征及对环境的适应

选取广西弄拉典型峰丛洼地生态系统中不同地貌类型的青冈栎 (Cyclobalanopsisglauca)叶片进行形态解剖特征比较分析 ,结果表明 :( 1 )峰丛洼地生态系统中不同地貌青冈栎叶片形态解剖特征差异显著。山顶青冈栎叶片部分表皮结构 (角质膜、表皮毛、表皮细胞、气孔 )趋向旱化。山顶青冈栎下表皮毛比山腰青冈栎的浓密且长。两者叶片的厚度和宽度、上表皮细胞个数、气孔指数、下表皮厚度、栅栏组织厚度、海绵组织厚度存在着显著性差异 ;位于山顶的青冈栎受到水分的胁迫 ,在形态解剖上呈现出中生偏旱的结构。 ( 2 )青冈栎的各种形态解剖指标说明在岩溶区青冈栎的抗旱性主要是通过抵御干旱来适应水分的胁迫 ,并主要取决于减少蒸腾失水和维持水分吸收能力两个方面     

不同土壤水分条件下小叶扶芳藤叶片光合作用对光的响应

利用CIRAS-2型便携式光合作用仪测定不同土壤水分下3年生小叶扶芳藤(Euonymus fortunei var.radicans Sieb.)叶片净光合速率(Pn)、蒸腾速率(Tr)、水分利用效率(WUE)及光能利用效率(LUE)等生理参数,阐明其光合生理参数对土壤水分和光照强度的响应规律,探讨小叶扶芳藤正常生长发育所需的土壤水分和光照条件.结果表明小叶扶芳藤的Pn、Tr、WUE及LUE对土壤水分和光照强度的变化具有明显的阈值.(1)采用非直角双曲线模型进行模拟光响应过程较好,在土壤相对含水量(RWC)为72.2%和32.3%时,曲角(K)值较小;在其它水分条件下,K值接近于1.随着土壤水分(RWC为22.4%～72.2%)的递增,光补偿点降低,光饱和点、最大净光合速率及表观量子效率均呈现升高趋势,在RWC为72.2%时,光补偿点最低(22.6 μmol·m-2·s-1),光饱和点最高(1 400μmol·m-2·s-1).(2)维持小叶扶芳藤正常生长(同时具有较高Pn、LUE及WUE)的土壤水分范围,在RWC为44.2%～72.2%之间,最佳土壤水分在RWC为72.2%左右,正常生长所允许的最低土壤水分在RWC为32.3%左右.(3)小叶扶芳藤对光照环境的适应性较强,在光合有效辐射强度为600～1 600 μmol·m-2·s-1范围内,Pn和WUE都具有较高水平,饱和光强大约在800～1 400 μmol·m-2·s-1之间,LUE在100～300 μmol·m-2·s-1光强范围内达到峰值.     

六种藓类植物茎的比较解剖学研究

通过对6种藓类植物,即褶叶青藓(Brachythecium salebrosum(Web.et Mohr.)B.S.G.)、湿地匐灯藓(Plagiomnium acutum(Lindb.)Kop.)、侧枝匐灯藓(Plagiomnium maximoviczii(Lindb.)Kop.)、大凤尾藓(Fissidensnobilis Griff.)、大羽藓(Thuidium cymbifolium(Doz.et Molk.)B.S.G.)和大灰藓(Hypnum plumaeforme Wils.)嫩茎和老茎的石蜡切片和显微观察发现,同一藓类植株的嫩茎和老茎,茎结构稳定,不同种藓类植物茎横切面具有不同特征.植物体茎横切面形状、表层细胞的层数、细胞大小和细胞壁厚薄、皮层细胞大小和形状、中轴的有无以及比例等特征可以作为藓类植物的分科分类依据之一.     

Photoregulation of seed germination of wild-type and of an aurea-mutant of tomato

Seed germination of an aurea mutant of tomato ( Lycopersicon esculentum Mill.) is promoted by continuous irradiation with red, far-red or long-wavelength far-red (758 nm) light as well as by cyclic irradiations (5 min red or 5 min far-red/25 min darkness). Far-red light applied immediately after each red does not change the germination behaviour. Seed germination of the isogenic wild-type, cv. UC-105, is promoted by continuous and cyclic red light while it is inhibited by continuous and cyclic far-red light and by continious 758 nm irradiation. Far-red irradiation reverses almost completely the promoting effect of red light. The promoting effect (in the aurea mutant) and the inhibitory effect (in the wild-type) of continuous far-red light do not show photon fluence rate dependency above 20 nmol m⁻² s⁻¹. It is concluded that phytochrome controls tomato seed germination throgh low energy responses in both the wild type and the au mutant. The promoting effect of continuous and cyclic far-red light in the au mutant can be attributed to a greater sensitivity to P_fr.     

Cause of Senescence of Nine Sorts of Flowers

The levels of endogenous phytohormones and respiratory rate in nine sorts of flowers such as Cymbidium faberi Rolfe, Nopalxochia ackermannii Kunth and others were investigated both at full bloom and senescence and meanwhile the effect of exogenous phytohormones on prolonging the blossoms and promoting ethylene production were tested. There is a high content of endogenous ethylene in all the long-lived flowere, about 3–16 folds higer than the short-lived ones. There is a high level of ABA at full blooming flowers of short-lived flowers, in which there is no or only some cytokinins in it, but the ratio of CTK (6BA+zeatin)/ABA is smaller(l.7). The endogenous ABA reached a much higher level at senescence in all nine sorts of flowers, so it is reasonable to consider that it is ABA which plays an important role of regulation in controlling flower's senescence. There is a much higher level of GA3 and zeatin in the long-lived flowers which is not demonstrated in the shortlived ones. The respiratory rate is one of the factors controtling the longevity of flowers, but it does not play a decided role. Application of 6BA and zeatin prolongs distinctly orchid’s longevity, however exogenous IAA through the promotive action on ethylene production, evidently extends the longevity of the flowers of the Nopalxochia ackermannii Kunth.     

龙胆科药用植物化学成分的研究现状

龙胆科植物在我国的分布范围很广,且多数为药用植物,其多数种属的药用植物,至今其化学成分尚未被系统研究。综述了目前龙胆科药用植物的化学成分的研究现状及一般提取方法,对近年来发现的环烯醚萜及裂环烯醚萜类化合物进行了总结,为本科药用植物的更深入研究提供了参考。     

Interconnection of parameters of regulation system of lipid peroxidation and of morphophysiological parameters of mouse liver

A complex analysis of seasonal fluctuations of the mean group parameters of the system of regulation of lipid peroxidation has been performed in liver of Balb/c mice. Association of lipid characteristics and morphophysiological parameters is studied in the Balb/c mouse liver. An inter-connection is revealed between the liver index and the amount of lysoforms of phospholipids, the scale and character of the interconnection differing essentially depending on proportion of phos-phatidylcholine in mouse liver phospholipids.     

真菌类遗传学分析的知识结构教学

本文以认知结构理论为指导,讨论了真菌类遗传分析与高等动植物遗传分析的内在联系,认为利用这种内在联系进行教学可收到好的效果并说明了作者的具体教学过程。 Abstract:In the paper, the relationship between genetic analysis of Fungi and genetic analysis of high animal and plant was discussed.A good results were obtained when we adopted this method in the teaching.     

Physiological characteristics of various species of strains of carboxydobacteria

Seven strains of aerobic carbon monoxide-oxidizing bacteria (carboxydebacteria) when growing on CO as sole source of carbon and energy had doubling times which ranged from 12–42 h. The activity profiles obtained after discontinuous sucrose density gradient centrifugation indicated that the CO-oxidizing enzymes are soluble and the hydrogenases are membrane-bound in all strains examined. The CO-oxidizing enzymes of Pseudomonas carboxydohydrogena, Pseudomonas carboxydoflava, Comamonas compransoris, and the so far unidentified strains OM2, OM3, and OM4 had a molecular weight of 230,000; that of Achromobacter carboxydus amounted to 170,000. The molecular weights of the CO-oxidizing and H₂-oxidizing enzymes turned out to be identical. The cell sonicates were shown to catalyze the oxidation of both CO and H₂ with methylene blue, thionine, phenazine methosulfate, toluylene blue, dichlorophenolindophenol, cytochrome c or ferricyanide as electron acceptors. Methyl viologen, benzyl viologen, FAD⁺, FMN⁺, and NAD(P)⁺ were not reduced. The spectrum of electron acceptors was identical for all strains tested. Neither free formate, hydrogen nor oxygen gas were involved in the CO-oxidation reaction. Methylene blue was reduced by CO at a 1:1 molar ratio. The results indicate that CO-oxidation by carboxydobacteria is catalyzed by identical or similar enzymes and that the reaction obeys the equation CO+H₂OCO₂+2H⁺+2e^- as previously shown for Pseudomonas carboxydovorans.Dedicated to Otto Kandler remembering almost three decades of enjoyable cooperation     

Modulation of allostery of pyruvate kinase by shifting of an ensemble of microstates

Since the introduction of the concepts of allostery about four decades ago, much advancement has been made in elucidating the structure-function correlation in allostery. However, there are still a number of issues that remain unresolved. In this review we used mammalian pyruvate kinase (PK) as a model system to understand the role of protein dynamics in modulating cooperativity. PK has a triosephosphate isomerase (TIM)(α/β)₈ barrel structural motif. PK is an ideal system to address basic questions regarding regulatory mechanisms about this common (α/β)₈ structural motif. The simplest model accounting for all of the solution thermodynamic and kinetic data on ligand-enzyme interactions involves two conformational states, inactive E^T and active E^R. These conformational states are represented by domain movements. Further studies provide the first evidence for a differential effect of ligand binding on the dynamics of the structural elements, not major secondary structural changes. These data are consistent with our model that allosteric regulation of PK is the consequence of perturbation of the distribution of an ensemble of states in which the inactive E^T and active E^R represent the two extreme end states. Sequence differences and ligands can modulate the distribution of states leading to alterations of functions. The future work includes: defining the network of functionally connected residues; elucidating the chemical principles governing the sequence differences which affect functions; and probing the nature of mutations on the stability of the secondary structural elements, which in turn modulate allostery.