荒漠刺叶墙藓DNA的提取及PCR扩增反应条件

采用改进CTAB法、NaOH法和直接PCR法(direct PCR amplification)提取藓类生物结皮中刺叶墙藓(Tortula desertorumBroth.)基因组DNA,比较其分离效果以及ISSR扩增效果。结果表明:改进CTAB法提取的基因组DNA质量好、纯度高,ISSR扩增反应效果好。直接PCR法一旦体系建立,则是最简易快速、经济高效的模板制备方法,适于植株矮小、生物量很小的荒漠藓类植物个体模板DNA的制备。利用改进CTAB法获得的基因组DNA作为模板,对ISSR反应组分浓度及反应程序中的一些重要参数进行摸索和优化实验,建立了刺叶墙藓最优ISSR反应体系。反应总体积为20μL,各反应组分终浓度为:2μL10×Buffer,2 mM Mg2 ,0.1 mM dNTPs,0.2μM引物,10~40 ng模板DNA,1U Taq酶。扩增程序为:94℃4 min,1个循环;94℃45 s,退火温度(Tm)45 s,72℃1 min,35个循环;72℃7 min,1个循环;4℃保存。刺叶墙藓是组成古尔班通古特沙漠藓类生物结皮的优势种,研究结果为进一步开展刺叶墙藓遗传多样性的研究奠定了基础。     

十种藓类植物茎的比较解剖学观察

利用石蜡切片的方法 ,对十种藓类植物 ,钝叶蓑藓 (Macromitriumjaponicum Doz.et.Molk .)、疏齿墙藓〔 Tortulanorvegica(Web .)Wahl.exLindb .〕、岸生连轴藓〔 Schistidiumrivularis(Brid .)Podp .〕、树形疣灯藓〔Trachycystisussuriensis(MaacketRegel )T .Kop .〕、齿边缩叶藓〔 Ptychomitriumdentatum(Mitt.)Jaeg .〕、山羽藓〔 Abietinellaabietina(Hedw .)Fleisch〕、东亚万年藓 ( Climaciumjaponicum Lindb .)鼠尾藓〔 Myurocladamaximowiczii(Borszcz)SteeretSchof.〕、卷叶凤尾藓 (FissidensdubiusP .Beauv .)及二形凤尾藓 (FissidensgeminiflorusDoz .etMolk .)的茎横切面的解剖观察结果表明 :茎的形状、中轴细胞的有无、形状及所占的比例、外皮部厚壁细胞的层数等特征因种类不同而有明显差异 ,可以作为分类依据之一。外皮部厚壁细胞的层数可能与藓类植物的生境有关。     

新疆天山高寒地区10种青藓科植物叶的微结构观察

本文采用光镜与扫描电镜,对新疆天山高寒地区10种青藓科植物叶的微结构进行了研究,观察得出10种青藓科植物叶尖渐尖或为长毛尖,叶尖顶端细胞透明,短或狭长;叶片细胞壁加厚;导水细胞较大。植株的叶片干燥时,细胞壁的凹凸程度不同,表面具不同形状的纹饰及附属物,大多数种类的表面有小窝点分布,但这些微结构在青藓属(Brachythecium B.S.G.)、毛尖藓属(Cirriphyllum Grout.)、长喙藓属(Rhynchostegium B.S.G.)植物叶中均有明显差异。同属、不同属之间,由于生长环境不同,植物体叶也会呈现出不同的形态特征。这表明10种植物的微结构特征是与环境密切相关。     

不同沙埋深度对刺叶墙藓植株碎片生长的影响

采用撒茎法对构成古尔班通古特沙漠苔藓结皮的优势种刺叶墙藓(Tortula desertorum Broth.)进行室内沙培实验,探讨不同沙埋深度对刺叶墙藓无性繁殖的影响.结果表明:(1) 在不添加任何营养元素或激素的原沙基质培养条件下,刺叶墙藓的植株碎片仍然能够生长并发育成完整的植物体.(2)在所设置的不同沙埋厚度条件下,刺叶墙藓的植株碎片在2 mm沙埋厚度时生长较好,生长趋势表现为:前12 d内生长较快,之后生长缓慢.第22 d以后,未见新生植株,苔藓植株数趋于稳定.大于2 mm的沙埋厚度则抑制其生长.同时指出,沙埋也是影响古尔班通古特沙漠苔藓植物生长和分布的因素之一.     

新疆薄罗藓科(Leskeaceae)植物分类的初步研究

通过对产自新疆的薄罗藓科5属8种的分类学研究,包括多毛藓属Lescuraea Bruch & Schimp. in B.S.G. 的弯叶多毛藓L. incurvata (Hedw.) Lawton,密根多毛藓 L. radicosa (Mitt.) Moeck.,石生多毛藓L. saxicola (Schimp. in B.S.G.) Mol. in Lor.;薄罗藓属Leskea Hedw. 的薄罗藓L. polycarpa Hedw. ;细罗藓属Leskeella (Brid.) Loeske 的细罗藓L. nervosa (Brid.)Loeske ;细枝藓属Lindbergia (C. Müll) Broth. 的中华细枝藓L. sinensis (C. Müll) Broth. ,以及假细罗藓属 Pseudoleskeella Kindb. 的假细罗藓P. catenulata (Brid. ex Schrad.) Kindb.和瓦叶假细罗藓P. tectorum (Brid. )Kindb.。其中,薄罗藓属Leskea Hedw.为新疆新记录属;薄罗藓Leskea polycarpa Hedw. 和密根多毛藓Lescuraea radicosa (Mitt.) Moeck. 是新疆新记录种。根据标本形态特征,编制了新疆薄罗藓科植物分属、分种检索表,简要讨论了其生境和地理分布特点。     

河北省薄罗藓科植物分类的初步研究

报道了河北省薄罗藓科植物6属共12种（含1变种），其中中国新记录种1种：北方假细罗藓Pseudoleskeella papillosa(Lindb.)Kindb.；河北省新记录属2属：薄罗藓属Leskea Hedw.和褶藓属Okamuraea Broth.；河北新记录种7种：薄罗藓Leskea polycarpi Hedw.，细枝藓Lindbergia brachyptera(Mitt.)Kindb.，细枝藓疣齿变种L. brachyptera var.austinii (Sull.)Grout.,阔叶细枝藓L. brevifolia(Gao)Gao，瓦叶假细罗藓Pseudoleskeella tectorum(Brid.)Kindb.,褶藓O.hakoniensis(Mitt.)Broth.和短枝褶藓O.brachydictyon(Card.）Nog..本文根据标本编制了河北省薄罗藓科植物分属、种检索表，简要讨论了其生境行理分布特点。旨在为河北省乃至中国苔藓植物的系统研究及苔藓植物资源的开发利用提供可借鉴的资料。研究标本保存在河北师范大学植物标本室（HBNU)。     

乌鲁木齐河源区10种真藓属植物茎的解剖学分析

利用石蜡切片和电镜扫描技术,对乌鲁木齐河源区10种真藓属植物茎的结构做比较解剖学研究。结果表明:该属植物茎分为表皮、皮部、中轴3部分,表皮细胞小,细胞壁强烈加厚;皮部细胞壁由外向内逐渐变薄,细胞整齐或镶嵌排列;中轴所占面积较小,细胞壁角隅加厚。茎细胞壁上分布有不规则的小孔,相邻细胞的细胞壁厚,表面角质层纹饰多为鳞片状或颗粒状,这些可能是植物在长期恶劣环境下的生存策略,揭示了真藓属植物茎具有较强耐寒、耐旱结构的典型特征,虽然它们在外形和亲缘关系上均很接近,但每个种又各具不同的形态特征,为该属植物鉴定提供了分类学依据。     

新疆天山高寒地区10种青藓科植物叶的微结构观察北大核心CSCD

本文采用光镜与扫描电镜,对新疆天山高寒地区10种青藓科植物叶的微结构进行了研究,观察得出10种青藓科植物叶尖渐尖或为长毛尖,叶尖顶端细胞透明,短或狭长;叶片细胞壁加厚;导水细胞较大。植株的叶片干燥时,细胞壁的凹凸程度不同,表面具不同形状的纹饰及附属物,大多数种类的表面有小窝点分布,但这些微结构在青藓属（Brachythecium B.S.G.）、毛尖藓属（Cirriphyllum Grout.）、长喙藓属（Rhynchostegium B.S.G.）植物叶中均有明显差异。同属、不同属之间,由于生长环境不同,植物体叶也会呈现出不同的形态特征。这表明10种植物的微结构特征是与环境密切相关。     

黄土地与沙地生物结皮的发育特征及其生态功能异同

基于课题组已有研究成果,选取陕北水蚀风蚀交错区内气候条件相同但土壤质地迥异的试验区,探讨黄土地和沙地生物结皮发育特征及其生态效应的异同。结果表明:(1)苔藓结皮是2种土地生物结皮的重要类型,其中,黄土地的优势藓种为尖叶对齿藓[Didymodon constrictus(Mitt.)Saito.]、真藓(Bryum argenteum Hedw.)、狭网真藓(B.algovicum Sendt.);沙地的优势藓种为黄色真藓(B.pallescens Scheich.)、弯叶真藓(B.recurvulum Mitt.)、银叶真藓(B.argenteum Hedw.)。沙地乔灌植物下生物结皮盖度(77.5%)、厚度(11.8 mm)及容重(1.9 g·cm~(-3))均高于黄土地生物结皮,而黄土地多年生草本植物下生物结皮抗剪强度(26.5 k Pa)高于沙地生物结皮,总体上,沙地生物结皮发育的更好。(2)黄土地的入渗增幅和0~200 cm剖面的平均土壤含水率增幅均显著高于沙地(P0.05),且在旱季和雨季其0~200 cm剖面的平均土壤含水率增幅分别比沙地高1.4%和1.9%。(3)两地生物结皮均表现出了较好的减蚀作用,其减蚀效率分别为81.0%和90.6%。     

新疆三种旱生藓类植物的比较解剖学观察

本文应用石蜡切片法及扫描电镜相结合的方法对旱生藓类植物茎、叶内部及表面同时进行分析分析,观察到旱藓（Ｉｎｄｕｓｉｅｌｌａｔｈｉａｎｓｃｈａｎｉｃａ Ｂｒｏｔｈ ｅｔ Ｃ．Ｍｕｅｌｌ）茎的皮部细胞面民中冰细胞面积相差悬殊,叶背面细胞皱折相对平滑;山地紫萼藓（ＧｒｉｍｍｉａｍｏｎｔａｎａＢｒｕｃｈｅｔＳｃｈｉｍｐ）茎的内皮层与单子叶植的的内皮层相似,叶背面皮表皱折呈鳞片状;细叶筛齿藓（Ｓｃｈｉｓｔｉｄ     

Effects of biological soil crusts and drought on emergence and survival of a Patagonian perennial grass in the Monte of Argentina

Biological soil crusts are widely distributed in arid and semiarid regions. They have an important eco- logical role, especially by modifying physical and chemical properties of soils. Biological crusts may also modify seed germination and seedling establishment. The effects vary widely according to the type of crust and the vas- cular plant species. The objective of this study was to determine the effect of moss-dominated biological soil crusts on the emergence, biomass and survival of Poa ligularis Nees ex Steud. under different irrigation regimes. We col- lected seeds of P. ligularis and biological soil crusts composed of two species of mosses： Syntrichia princeps （De Not.） Mitt and Ceratodon purpureus （Hedw.） Brid. from an area in the Monte of Argentina. The result showed that seedling emergence of P. ligularis was higher in treatments with bare soil than in soil covered by crusts, and also in those with watering to field capacity. Mean emergence time was higher in treatments with bare soil and watering to field capacity. Seedling biomass also showed significant differences between treatments. These results suggest that biological soil crusts dominated by mosses do not promote P. ligularis emergence, although they would not affect its survival.     

新疆木灵藓属Orthotrichum Hedw.植物的分类学研究

根据历年采自新疆各地区的350号木灵藓属Orthotrichum 植物标本,在查阅大量文献的基础上,通过经典分类学方法,对新疆木灵藓属植物进行了整理、鉴定和分类。结果表明：新疆有木灵藓属植物5亚属、17种,包括裸孔亚属subg. Gymnoporus (6种) 、直叶亚属subg. Orthophyllum (1种)、疣叶亚属subg. Pulchella (5种)、圆孔亚属subg. Phaneroporum (1种)、木灵藓亚属subg. Orthotrichum (4种),其中高山木灵藓Orthotrichum alpestre Hornsch. ex B.S.G为中国新记录种;中国木灵藓O. hookeri Wils. ex Mitt.、东亚木灵藓O. ibukiense Toy.、短丛木灵藓O. pumilum Sw. 和卷叶木灵藓O. revolutum C. Muell. 为新疆新记录种。通过对新疆新记录种的生境、识别特征、采集地点、地理分布、海拔等信息的整理分析,绘制了4个种的线条图,并编制了新疆木灵藓属植物的分亚属和分种检索表。     

土壤微生物在生物结皮形成中的作用及生态学意义

在荒漠地区的固定、半固定沙地和流动沙地上,微生物、藻类植物及地衣、苔藓植物能参与并形成生物结皮,其在干旱和半干旱荒漠地区具有重要生态意义。其中土壤微生物因其极强的适应性和生存能力,在生物结皮形成各阶段都起着积极的作用。土壤微生物的生长和活性与土壤酶活性的变化具有良好的相关性,它的组成、分布和数量因沙丘类型和沙土层深度的不同而有所变化,也受到季节和植被的影响。土壤微生物的生理代谢活动及数量变化可以改变沙土表面理化性质,在土壤结皮的形成、植物营养的转化过程中发挥积极作用,为植物生长创造了良好的条件。     

Carbon fixation and influencing factors of biological soil crusts in a revegetated area of the Tengger Desert,northern China

Biological soil crusts （BSCs） are an important type of land cover in arid desert landscapes and play an important role in the carbon source-sink exchange within a desert system. In this study, two typical BSCs, moss crusts and algae crusts, were selected from a revegetated sandy area of the Tengger Desert in northern China, and the experiment was carried out over a 3-year period from January 2010 to November 2012. We obtained the effec- tive active wetting time to maintain the physiological activity of BSCs basing on continuous field measurements and previous laboratory studies on BSCs photosynthesis and respiration rates. And then we developed a BSCs carbon fixation model that is driven by soil moisture. The results indicated that moss crusts and algae crusts had significant effects on soil moisture and temperature dynamics by decreasing rainfall infiltration. The mean carbon fixation rates of moss and algae crusts were 0.21 and 0.13 g C/（m2.d）, respectively. The annual carbon fixations of moss crusts and algae crusts were 64.9 and 38.6 g C/（m2.a）, respectively, and the carbon fixation of non-rainfall water reached 11.6 g C/（m2.a） （30.2% of the total） and 8.8 g C/（m2.a） （43.6% of the total）, respectively. Finally, the model was tested and verified with continuous field observations. The data of the modeled and measured CO2 fluxes matched notably well. In desert regions, the carbon fixation is higher with high-frequency rainfall even the total amount of seasonal rainfall was the same.     

Physiological responses of artificial moss biocrusts to dehydration-rehydration process and heat stress on the Loess Plateau,China

Ex-situ cultivation of biological soil crusts(biocrusts) is a promising technology to produce materials that can induce the recovery of biocrusts in the field for the purposes of preventing soil erosion and improving hydrological function in degraded ecosystems. However, the ability of artificially cultivated biocrusts to survive under adverse field conditions, including drought and heat stresses, is still relatively unknown. Mosses can bolster biocrust resistance to the stresses(e.g., drought and heat) and the resistance may be introduced prior to field cultivation. In this study, we subjected the well-developed artificial moss biocrusts(dominant species of Didymodon vinealis(Brid.) Zand.) that we cultivated in the phytotron to a dehydration-rehydration experiment and also a heat stress experiment and measured the activities of protective enzymes(including peroxidase(POD), superoxide dismutase(SOD), and catalase(CAT)) and the contents of osmoregulatory substances(including soluble proteins and soluble sugars) and malondialdehyde(MDA, an indicator of oxidative stress) in the stem and leaf fragments of mosses. The results showed that, during the dehydration process, the activities of protective enzymes and the contents of osmoregulatory substances and MDA gradually increased with increasing duration of drought stress(over 13 days). During the rehydration process, values of these parameters decreased rapidly after 1 d of rehydration. The values then showed a gradual decrease for 5 days, approaching to the control levels. Under heat stress(45°C), the activities of protective enzymes and the content of soluble proteins increased rapidly within 2 h of heat exposure and then decreased gradually with increasing duration of heat exposure. In contrast, the contents of soluble sugars and MDA always increased gradually with increasing duration of heat exposure. This study indicates that artificial moss biocrusts possess a strong drought resistance and this resistance can be enhanced after a gradual dehydration treatment. This study also indicates that artificial moss biocrusts can only resist short-term heat stress(not long-term heat stress). These findings suggest that short-term heat stress or prolonged drought stress could be used to elevate the resistance of artificial moss biocrusts to adverse conditions prior to field reintroduction.     

中国西北干旱荒漠区盐生植物资源与开发利用

盐生植物是指在3.3bar渗透压盐水的生境中生长并完成其生活史的植物，在我国西北干旱荒漠区中有12％的植物为盐生植物，共有208种，分属于31科、90属，占我国盐生植物总数的49％，具有丰富的盐生植物多样性。这些盐生植物不仅为农业生产提供了丰富的抗盐种质资源，为培育抗盐、耐盐的转基因作物品种提供基因库，而且在这些盐生植物中含有丰富的药用、食用、工艺以及绿化和固沙植物资源。在不能耕种的盐渍土上直接引种具有经济价值的盐生植物，可获得经济效益，以充分地利用西北干旱荒漠区大面积的土地资源，因此开发和利用盐生植物资源具有重要意义。     

塔克拉玛干沙漠南缘绿洲外围的天然植被

塔克拉玛干沙漠南缘是一片极端士昌的荒漠，生态环境严酷，脆弱；植物区系组成贫乏。根据植被生存所需要的水分来源，本文将绿洲外围的天然植被粗略地划分为雨育植物群落，毛管水植物群落，以及主要靠大气降水，地表散流渗透和土壤包气带中的水汽维持生存的兼性植物群落，主要靠大气降水从沙层中吸收凝结水维持生命活动的兼性植物群落；上述各类天然植物群落是保护绿洲支持系统的有机组成，使绿洲免于减轻风沙流入侵。     

不同沙丘部位和不同结皮类型对土壤种子库的影响

采用萌发法对古尔班通古特沙漠沙垄不同部位生物结皮类型的种子库进行研究,发现不同沙丘部位和结皮类型种子分布特征有一定的规律性:藻类结皮的种子数量、丰富度和多样性均显著高于地衣和苔藓结皮。生物结皮从藻类到地衣和苔藓的演替,有降低种子数量和种子多样性的现象。在不同沙丘部位,沙丘顶部流沙的种子数量和多样性较低,与丘顶流沙相比沙丘底部的藻类结皮显示出较高的丰富度和多样性,但沙丘底部的地衣和苔藓结皮与丘顶流沙相比未表现出明显的差异。背风坡中部的藻类结皮种子多样性较高,显著高于迎风坡中部的藻类结皮。     

新疆丝瓜藓属(Pohlia Hedw.)的分类学修订

基于标本和文献,对新疆丝瓜藓属（Pohlia Hedw.）进行全面修订,更正了此前部分标本的错误鉴定,将卵蒴丝瓜藓(Pohlia proligera)和糙枝丝瓜藓(P.camptotrachela)从本区名录中移除,将多态丝瓜藓(P.minor)归并为丝瓜藓多态变种(P.elongata var.greenii)的异名,新增新疆丝瓜藓属新纪录2种：拟长蒴丝瓜藓(P.longicollis)和小丝瓜藓狭叶变种(P.crudoides var.revolvens)。[WTBZ]现已知新疆丝瓜藓属有8种,2变种,种数约占全国的1/3。通过分析各个种的识别特征、与相近种的区别和生境,编制了新疆丝瓜藓属分种检索表。