中国柳叶藓科植物的研究－分类、区系和生态

柳叶藓科（Amblystegiaceae）是侧蒴藓类中一个较大的科，世界报导有 39 属，约 300 余种。由于其配子体特征受环境影响较大，其属种的分类位置历来存有争论。中国记载有柳叶藓科 115 个分类单位，己知 23 属，67 种，12 变种，3 变型（Redfearn, et al. 1996），其记录和标本鉴定比较混乱。因此，对中国柳叶藓科全面系统的分类、区系和生态研究，对深入了解中国苔藓植物多样性及特点有重要的科学意义。作者在大量文献查阅和考证后，对国外 9 个主要苔藓植物标本馆的有关中国柳叶藓科 47 份模式标本和标本 300 余份，国内 6 个主要标本馆的 3，000余份标本进行了全面系统的形态解剖学和分类学研究，对孢子和蒴齿的形态特征进行了扫描电镜观察。并采用等级聚类分析方法，对其属种间的系统关系、地理分布特点和区系成分定量研究。同时，在国内首次开展了藓类专科的生态学研究，在吉林长白山、黑龙江五营、辽宁白石砬子和医巫闾山保护区进行样方调查，对样方以及柳叶藓科植物与环境因子的关系进行了典范对应分析。研究的主要结果有：1. 对中国柳叶藓科进行系统分类的结果是共记录 19 属 46 种 5 变种。对每一分类单位给予形态特征描述和绘图，并利用 Arcview 软件绘制其中国分布图。发现中国新分布记录植物 3 种，1 变种：圆叶湿原藓 Calliergon megalophyllum Mikut, 毛叶镰刀藓 Drepanocladus trichophyllus (Warnst.) Podp, 细肋镰刀藓 Drepanoclaldus tenuinervis Kop. 和牛角藓宽肋变种 Cratoneuron filicinum var. atrovirens (Brid.) Ochyra。归并 Campylium amblystegioides Broth. (=Isopterygium minutirameum), Leptodictyum serrulatum Broth. (=Eurhychium pulchellum), Drepanophyllaria cuspidarioides C. Muell. ( = Hygroamblystegium tenax), Amblystegiella yuennanensis Broth. (= Platydictya jungermannioides) 和 Amblystegium schesianum C. Muell., Hygroamblystegium ramulosum Dixon, Cratoneuron longicosatatum Bai X.-L. (Cratoneuron filicinum) 7 个新同物异名，并纠正 9 个前人错误记录。2. 电镜扫描观察结果孢子大都近球形，通常无萌发孔，具近极薄壁区。纹饰皆由周壁形成，一般呈规则或不规则颗粒状、疣状或瘤状，区别在于孢子大小，颗粒或瘤或疣的大小、高度以及密集程度等。孢蒴多为长柱形，弯曲，只有三洋藓的孢蒴形态变化较大。藓齿两层为灰藓型蒴齿。齿毛数量和发育程度各异。总的来说，柳叶藓科植物的孢子体特征在属间或种间差别不大。3. 系统关系的等级聚类分析结果支持了近年来对柳叶藓科植物修订的某些属的概念。如传统上定义很广的细湿藓属（包括狭义的细湿藓属、嗜湿藓属和偏叶藓属）和水灰藓属在聚类树状图中常不聚合在一起。说明了广义细湿藓属的水灰藓属不是一个很自然的分类类群，而应该分为更细的属。柳叶藓属、湿柳藓属和薄网藓属的种类明显常聚在一起，位置较近，且比较稳定，可以同归于柳叶藓属。毛叶镰刀藓与范氏藓和大范氏藓的关系较近，说明适合将毛叶镰刀藓归并入范氏藓属中，范氏藓属和湿原藓属的较近。4. 对中国柳叶藓科的地理分布和区系成分的聚类分析表明，该科为典型的泛北极分布类型，大多分布于北半球的温带和寒带，59％为欧亚美共有种，14％为东亚特有成分，其中 8％ 为中国特有成分。属种的分布特点主要是，牛角藓属、柳叶藓属、细湿藓属、嗜湿藓属、三洋藓属和水灰藓属的中国分布比较广泛，大湿原藓属和偏叶藓属主要分布在东北地区和西南高山地区，而湿原藓属、范氏藓属和镰刀藓属则主要分布在东北地区。总的来说，气候较为寒冷的东北地区是中国柳叶藓科植物的主要分布区。西南地区的种类也较为丰富，是柳叶藓科植物的中国特有属种的分化中心。其他地区的柳叶藓样植物大多是分布在高山地区，表现出地区商的不平衡性。5. 对东北地区柳叶藓科植物的生态调查和典范对应分析研究进一步说明，柳叶藓科多分布于阴湿或水生生境，喜中性的酸碱条件。湿原藓属、范氏藓属、和镰也藓属植物常分布于沼泽，其中范氏藓属和镰藓属的一些种类常沉水或半沉水生长，而其他种类能分布于相对较干燥或季节性积水的地方。牛角藓属和水灰藓属植物常分布于溪流中，牛角藓属常分布于泉水或溪流的源头，而水灰藓属则喜流动的溪流。细湿藓属，柳叶藓属和嗜湿藓属植物的生境较为干燥，既能在林下土生、石生或树干生，也能分布于较为潮湿的生境。三洋藓常见于森林林下，在有些开阔地带也能生长分布，其生境范围明显较柳叶藓科其他各类为广，是唯一能适应陆生环境的柳叶藓科植物。对柳叶藓科植物与其环境因子的进行的典范对应分析结果表明，所研究的 26 种柳叶藓科植物大部分分布于水生环境，因其在排序图中与基质含水量接近。与基质含沙量、草本层郁蔽的相关也较大。其中水生环境下的 19 种柳叶藓科植物与水流速度和水体 pH 值关系较密切。

土壤微生物和酶对大气CO2浓度与温度升高的响应

土壤微生物(Soil microbes)是生态系统的重要组成部分，它参与土壤中复杂有机物质的分解和再合成，也参与C、N、S、P等的循环。土壤酶(Soil enzyme)是土壤中具有生物活性的蛋白质，它与微生物一起推动着土壤的生物化学过程，并在树木营养物质的转化中起着重要的作用。鉴于土壤微生物和土壤酶对环境变化的敏感性，它们在CO2浓度和温度升高时的反应将在很大程度上影响森林生态系统的结构和功能。因此，要全面评价大气CO2浓度和温度升高对整个生态系统的影响，有必要对CO2浓度和温度升高条件下的土壤微生物的反应进行深入的研究与探讨。本文应用自控、封闭、独立的生长室系统，研究了川西亚高山岷江冷杉（Abies faxoniana）根际、非根际土壤微生物数量，红桦（Betula albosinensis）根际微生物数量以及根际、非根际土壤酶活性对大气CO2浓度(环境CO2浓度+350±25μmol·mol-1，EC)和温度(环境温度+2.0±0.5℃，ET)升高及两者同时升高(ECT)的响应。结果表明： 1) EC和ET显著增加岷江冷杉根际微生物数量，但不同微生物种类对EC和ET的反应有所差异。6、8和10月，岷江冷杉根际微生物数量与对照(CK)相比，EC处理的根际细菌数量分别增加了35%、164%和312%，ET处理增加了30%、115%和209%；EC和ET处理对根际放线菌和根际真菌数量影响不显著。ECT处理的根际放线菌数量分别增加了49%、50%和96%，根际真菌数量增加了151%、57%和48%；而ECT对根际细菌数量影响不显著。EC、ET和ECT处理对岷江冷杉土壤微生物总数的根际效应明显，其R/S值分别为1.93、1.37和1.46(CK的R/S值为0.81)。 2) 红桦根际微生物数量对EC、ET和ECT的响应不同。生长季节(5~10月)，高密度的红桦根际细菌数量与CK 相比，EC的根际细菌数量分别增加28%、33%、423%、65%、43%和79%，而低密度的红桦根际细菌数量增加不显著。ET能显著增加根际细菌数量(7~10月)，其中高密度的根际细菌数量分别增加了377%、107%、35%、22%，而低密度的根际细菌数量分别增加了27%、27%、64%、48%；ECT对两个密度水平下根际细菌数量均未产生有显著的影响。高、低密度的红桦根际放线菌和根际真菌数量与 CK 相比，EC显著增加了低密度的红桦根际放线菌数量，而对高密度的根际放线菌数量无显著影响；ET和ECT对高低密度的红桦根际放线菌数量均未产生显著影响。EC和ET对高低密度的根际真菌数量也无显著影响，而ECT却显著增加了高低密度的根际真菌数量。 3) EC、ET和ECT处理的低密度红桦根际微生物(细菌、放线菌和真菌)数量没有显著高于或低于高密度根际微生物数量，表明短期内密度对红桦根际微生物数量不产生影响。 4) 不同种类的氧化还原酶对EC、ET和ECT的响应不同。5~10月，EC的红桦根际过氧化氢酶活性是CK 的1.44、1.06、1.11、1.10、1.12和1.24倍，差异显著(6月除外)；ET和ECT处理根际过氧化氢酶活性无显著增加。EC的红桦根际多酚氧化酶活性比CK显著增加；ET的根际多酚氧化酶活性显著高于CK(8月除外)。ECT的根际多酚氧化酶活性高于CK，差异不显著。EC的根际脱氢酶活性分别增加了46%、40%、133%、48%、17%和26%，差异显著。5~7月，ET和ECT的根际脱氢酶活性高于CK的脱氢酶活性，而8~9月则相反，差异性均不显著。 5) EC、ET和ECT对不同种类的水解酶的影响不同。EC能显著增加红桦根际脲酶活性，5~10月分别增加了29%、42%，、70%、67%、59%和57%。ET和ECT 对根际脲酶活性未产生显著影响。EC显著提高根际转化酶活性，5、6和9月EC的根际转化酶活性分别比CK高51%、42%和40%。5和10月，ET的根际转化酶活性低于CK，而其余月份却高于CK，但均具有显著性差异。ECT的根际转化酶活性与CK的根际转化酶活性有显著性差异(9月除外)，5、6和7月的根际转化酶活性分别提高了94%、198%和67%。 6) 与CK相比，EC、ET和ECT的非根际土壤微生物数量以及非根际土壤酶活性均无显著提高。EC、ET和ECT的过氧化氢酶、脲酶的根际效应明显，而多酚氧化酶和脱氢酶根际效应不明显。EC和ECT的转化酶根际效应明显，而ET的转化酶根际效应不明显。 It is well known that atmospheric CO2 concentration and temperature are increasing as a consequence of human activities. In past decades, considerable efforts had been put into investigating the effects of climate change on processes of forest ecological system. In general, studies had been mainly focused on the effects of elevated atmospheric CO2 on plant physiology and development, litter quality, and soil microorganisms. Studies showed that there was variation in the responses of root development and below-ground processes to climate between different plant communities. Since the concentration of CO2 in soil was much higher (10~50 times) than in the atmosphere, increasing levels of atmospheric CO2 may not directly in fluence below ground processes. Betula albosinensis and Abies faxoniana, as the dominated tree species of subalpine dark coniferous forest in the western Sichuan province, which play an important role in the structure and function of this kind of forest ecosystem. In our study, effects of elevated atmospheric CO2 concentration (350±25μmol·mol-1), increased temperature (2.0±0.5℃) and both of the two on the number of rhizospheric microbe and rhizospheric enzyme activity were studied by the independent and enclosed-top chamber’ system under high-frigid conditions. Responses of rhizospheric bacteria, actinomycetes and fungi number of Betula albosinensis and Abies faxoniana under different densities(high density with 84 stems·m-2, low density with 28 stems·m-2 ), and rhizospheric enzyme activity of Betula albo-sinensis to elevated CO2 concentration and increased temperature were analyzed and discussed. The results are as the following, 1) In comparion with the control, the numbers of rhizospheric bacteria of Abies faxoniana were increased by 35%, 164% and 312% significantly in June, August and October respectively of EC, and were increased by 30%, 115% and 209% respectively of ET.However the effect of EC and ET on rhizospheric actinomycetes and fungi was not significant. The number of rhizospheric actinomycetes of ECT were increased significantly by 49%, 50% and 96% respectively, and the increment of rhizospheric fungi were 151%, 57% and 48% respectively .The effect of ECT on rhizospheric bacteria was not significant. Rhizospheric effect of soil microbe for all treatments was significant, with the R/S of 1.93, 1.27 and 1.46 for EC, ET and ECT, respectively. 2) Treatment EC improved the number of rhizospheric bacteria of Betula albosinensis under high density significantly in comparison with the control, over the growing season, the greatest increment of rhizospheric bacteria was from July. However, EC had no effect on the number of rhizospheric bacteria under low density. Except May and June, treatment ET improved the number of rhizospheric signifcantly. The effect of treatment ECT on the number of rhizospheric bacteria under different densities was not significant. Of treatment EC, the number of rhizospheric actinomycetes of Betula albosinensis under low density were increased significantly, however, treatment EC did not stimulate the number of rhizospheric actinomycetes under high density. Simultaneously, treatment ET and ECT did not stimulate the number of rhizospheric actinomycetes. Finally, in treatment ECT, the number of rhizospheric fungi under high density were increased significantly, however treatment EC and ET did not stimulate the number of rhizospheric fungi under different densities. 3) Of treatment EC, ET and ECT, the number of rhizospheric microbe of Betula albosinensis under low density were not more or fewer than that of microbe under hign density along the growing season, which showed that plant density had no effect on the nmber of microbe. 4) From May to October, 2004，rhizospheric catalase activity of Betula albosinensis of treatment EC was 1.44, 1.06, 1.11, 1.10, 1.12 and 1.24 times as treatment CK respectively, and the difference was statistically significant(except June). Treatment ET and ECT did not increase rhizospheric catalase activity significantly. In treatment EC, the rhizospheric pohyphenol oxidase activity was higher than treatment CK significantly. The rhizospheric pohyphenol oxidase activity of treatment ET was higher than CK significantly (except August). The rhizospheric pohyphenol oxidase activity of treatment ECT was higher than CK, but the difference was not statistically significant. Over the growing period, the rhizospheric dehydrogenase activity were increased 46%, 40%, 133%, 48%, 17% and 26% respectively by treatment EC, and the difference was statistically significant. From May to July, the rhizospheric dehydrogenase activity in treatment ET and ECT was higher than CK, but from August to October, the rhizospheric dehydrogenase activity was lower than CK, the difference was not significant. 5) Treatment EC increased rhizospheric urease activity significantly, from May to October, rhizospheric urease activity were increased 29%, 42%, 70%, 67%, 59% and 57% respectively by EC. Treatment ET and ECT had no effect on rhizospheric urease activity. Treatment EC improved rhizospheric invertase activity significantly, in May, June and September, the rhizospheric invertase activity of treatment EC were increased 51%, 42% and 40% in comparison with the control. Except May and October, the rhizospheric invertase activity of treatment ET was markly higher than CK. The rhizospheric invertase activity of treatment ECT was significantly different from CK (except September), in May, June and July treatment ECT increased rhizospheric invertase activity by 94%, 198% and 67% respectively. 6) In comparison with the control, treatment EC, ET, and ECT had no effect on the number of non-rhizospheric microbe and non-rhizospheric enzyme activity. Rhizospheric effect of catalase and urease for all treatments was significant, but rhizospheric effect of pohyphenol oxidase and dehydrogenase was not significant. Rhizospheric effect of invertase of EC and ECT was significant, but rhizospheric effect of invertase of ET was not significant.

黄龙世界自然遗产地岷江冷杉原始林群落结构与植物多样性：生境差异性研究

黄龙世界自然遗产地岷江冷杉林(Abies faxoniana)生境类型多样，群落结构复杂，群落植物种类组成多样性丰富。揭示不同生境的生物多样性及其差异是认识生物多样性格局、形成及维持机制的前提和进行多样性保育的基础。本文采用样方法对黄龙钙化滩生境、阴坡非钙化生境及半阳坡非钙化生境的岷江冷杉原始林植物群落结构及植物多样性进行了研究。结果表明： 黄龙岷江冷杉林具有明显的复层异龄结构，垂直结构明显，乔木、灌木、草本、苔藓层次分明。共发现高等植物386 种，其中维管植物46 科103 属163 种，苔藓植38 科83 属物223 种。各层片结构及物种组成如下: (1)钙化滩生境、阴坡非钙化生境、半阳坡非钙化生境分别发现乔木18 种、13种、8 种。乔木层均可分为两个亚层，第一亚层优势种均为岷江冷杉，第二亚层主要为岷江冷杉异龄树或其它大高位芽物种。钙化滩生境第一亚层除优势种岷江冷杉外混生有巴山冷杉(Abies fargesii)、粗枝云杉(Picea asperata)以及阔叶树种白桦(Betula platyphylla)等，第二亚层主要为岷江冷杉异龄树；阴坡非钙化生境第一亚层除优势种岷江冷杉外间有巴山冷杉和白桦，第二亚层物种主要为川滇长尾槭(Acer caudatum var. prattii)；半阳坡非钙化生境第一亚层除优势种岷江冷杉外混生有巴山冷杉，第二亚层主要为岷江冷杉异龄树。依乔木层优势种的差异，钙化滩生境及半阳坡非钙化生境为岷江冷杉纯林，阴坡非钙化生境为岷江冷杉－川滇长尾槭混交林。不同生境乔木层郁闭度、乔木密度、树高结构、直径结构均存在差异。 (2)钙化滩生境发现灌木41 种，平均盖度为18.49±1.72(％)，平均高度为52.12±4.45(cm)，优势种为直穗小檗(Berberis dasystachya)；阴坡非钙化生境发现灌木30 种，平均盖度为29.33±2.56 (％)，平均高度为119.55±8.01 (cm)，优势种为箭竹 (Fargesia spathacea) 、唐古特忍冬(Lonicera tangutica) 和袋花忍冬(Lonicera saccata)；半阳坡非钙化生境发现灌木29 种，平均盖度为31.35±1.93 (％)，平均高度为107.55±4.24 (cm)，优势种为箭竹(Fargesia spathacea)。不同生境灌木层结构和物种组成多样性差异显著，钙化滩生境的灌木盖度、高度总体上较非钙化的坡地生境低, 钙化滩生境灌木以小型叶的落叶灌木为主，沟两侧非钙化的坡地生境上则发育了丰富箭竹。 (3)钙化滩生境发现草本46 种，平均盖度为7.18±0.79 (％)，平均高度为5.04±0.26(cm)，以山酢浆草(Oxalis griffithii)为优势种；阴坡非钙化生境发现草本物种71 种，平均盖度达29.04±2.31(％)，平均高度为9.08±0.52(cm)，以钝叶楼梯草(Elatostema obtusum)、山酢浆草为优势种；半阳坡非钙化生境草本物种50 种，平均盖度为以8.79±0.82(％)，平均高度为7.67±0.43 (cm)，以扇叶铁线蕨(Adiantum flabellulatum)、双花堇菜(Viola biflora)、华中蛾眉蕨(Lunathyrium shennongense)、山酢浆草为优势种。阴坡非钙化生境草本层片发育良好，多样性最为丰富，盖度和物种丰富度均显著高于钙化滩生境和半阳坡非钙化生境。 (4)钙化滩生境发现苔藓物种140 种，平均盖度达84.25±1.30 (％)，以仰叶星塔藓(Hylocomiastrum umbratum) 等大型藓类为优势种；阴坡非钙化生境发现苔藓物种115 种，平均盖度为79.29±1.64 (％)，以刺叶提灯藓(Mnium spinosum)、大羽藓(Thuidium cymbifolium)、毛尖燕尾藓(Bryhnia trichomitra)等个体较小的物种为优势种；半阳坡非钙化生境发现苔藓物种91 种，平均盖度为60.64±1.93 (％)，也以刺叶提灯藓为优势种。 (5)钙化滩生境、阴坡非钙化生境、半阳坡非钙化生境的物种数分别为234 种、221 种、175 种。乔木层的Shannon-Wiener 指数分别为0.75 ±0.12、1.87±0.12、1.78±0.07（灌木层，0.44±0.08、1.71± 0.15、2.49±0.06；草本层，0.33±0.13、1.31±0.15 、2.15±0.08； 苔藓层1.30±0.11、2.08±0.04、1.73±0.11，）；Pielou 均匀度指数分别为0.45±0.05、0.29±0.06、0.28±0.08（灌木层，0.75±0.03、0.68±0.05、0.52±0.06；草本层，0.68±0.02、0.77±0.02、0.74±0.02；苔藓层，0.40±0.03、0.63±0.02、0.52±0.03）；Simpson's 优势度指数分别为0.63±0.06、0.78±0.04、0.83±0.07（灌木层，0.21±0.03、0.28±0.05、0.45±0.06；草本层，0.25±0.02、0.12±0.01、0.17±0.01；苔藓层，0.45±0.04、0.18±0.01、0.31±0.04）。三种生境间乔木层、草本层的Sorenson 群落相似性系数较低, 灌木层、苔藓层的的Sorenson 群落相似性系数较高。 综上所述，黄龙岷江冷杉林的群落结构、植物多样性在三种生境间存在差异性，这将意味着我们在进行黄龙世界自然遗产地的森林经营管理时要较多地关注岷江冷山林群落在不同生境中的差异性。 There were multiplex habitat types, complicated community structure and abundant species composition in the Huanglong World Natural Heritage Site. Uncovering the differences of biodiversity among different habitats was a precondition to understand the distribution, formation and sustaining mechanism of the biodiversity, and the foundation of biodiversity conservation. In the present study, using plenty of quadrants, we investigated the community structure and the biodiversity of the primitive Abies faxoniana forest in different habitats (travertine bottomland, semi-sunny-slope non-calcified habitat and shady-slope non-calcified habitat) in the Huanglong World Natural Heritage Site. The main results are as follows: All the primitive Abies faxoniana forests in the three habitats were uneven-aged with obvious vertical structure including tree layer, shrub layer, herb layer and bryophyte layer. A total of 386 higher plants including 163 vascular plant species (103 generic, 46 families) and 223 bryophyte species (83 generic, 38 families) were investigated. The structure and species composition of each layer are as follows: (1) There were 18, 13 and 8 tree species in travertine bottomland, shady-slope non-calcified habitat and semi-sunny-slope non-calcified habitat, respectively. The tree layers in all habitats can be divided into two clear sub-layers. The upper tree layers were dominated by Abies faxoniana, and the lower tree layers were dominated by uneven-aged Abies faxoniana or other phanerophytes species. There were Abies fargesii , Picea asperata and Betula platyphylla besides the dominated species (Abies faxoniana) in the upper tree layer in travertine bottomland, and the lower tree layers were dominated by uneven-aged Abies faxoniana; There were Abies fargesii and Betula platyphylla besides the dominated species (Abies faxoniana) in the upper tree layer in shady-slope non-calcified habitat, and the lower tree layers were dominated by Acer caudatum var. prattii; There was Abies fargesii besides the dominated species (Abies faxoniana) in the upper tree layer semi-sunny-slope non-calcified habitat, and the lower tree layers were dominated by uneven-aged Abies faxoniana. According to composition percentage of dominate species in tree layer, both the forest in travertine bottomland and in semi-sunny-slope non-calcified habitat could be ranked as pure forest, and the forest in shady-slope non-calcified habitat could be ranked as mingled forest. There were significant differences in crown density, plant density, height structure and diameter structure among the three habitats. (2) A total of 41 shrub species (average coverage 18.49±1.72％; average height 52.12±4.45 ㎝)were found in travertine bottomland, and the dominate species was Berberis dasystachya; A total of 30 shrub species (average coverage 29.33±2.56 ％;average height 119.55±8.01 ㎝)were found in shady-slope non-calcified habitat, and the dominate species was Fargesia spathacea, Lonicera tangutica and Lonicera saccata. A total of 29 shrub species (average coverage 31.35±1.93％; average height 107.55±4.24 ㎝) were found in semi-sunny-slope non-calcified habitat, and the dominate species was Fargesia spathacea. There were significant differences in structure and species diversity of the shrub layers among the three habitats. The coverage and height of shrub had lower value in travertine bottomland than in two non-calcified habitats. Moreover, travertine bottomland was dominated by deciduous shrub species with microphyll and non-calcified habitats developed abundant Fargesia spathacea species. (3) A total of 46 herb species (average coverage 7.18±0.79％;average height 5.04±0.26 ㎝)were found in travertine bottomland, and the dominate species was Oxalis griffithii; A total of 71 herb species (average coverage 29.04±2.31％;average height 9.08±0.52 ㎝)were found in shady-slope non-calcified habitat, and the dominate species was Elatostema obtusum and Oxalis griffithii. A total of 50 herb species (average coverage 8.79±0.82％;average height 7.67±0.43 ㎝) were found in semi-sunny-slope non-calcified habitat, and the dominate species was Adiantum flabellulatum, Viola biflora, Lunathyrium shennongense and Oxalis griffithii. Herb layers developed well in shady-slope non-calcified habitat and had the higher species richness and coverage than travertine bottomland and semi-sunny-slope non-calcified habitat. (4) A total of 140 bryophyte species (average coverage 84.25±1.30％)were found in travertine bottomland, and the dominate species was big bryophyte species such as Hylocomiastrum umbratum and so on; A total of 115 bryophyte species (average coverage 79.29±1.64％)were found in shady-slope non-calcified habitat, and the dominate species was small bryophyte species such as Mnium spinosum, Thuidium cymbifolium, Bryhnia trichomitra and so on. A total of 91 bryophyte species (average coverage 60.64±1.93％) were found in semi-sunny-slope non-calcified habitat, and the dominate species was Mnium spinosum. (5) There were 234, 221 and 175 plant species in travertine bottomland, shady-slope non-calcified habitat and semi-sunny-slope non-calcified habitat, respectively. Shannon-Wiener index of the tree layer was 0.75 ±0.12, 1.87±0.12 and 1.78±0.07 (the shrub layer, 0.44±0.08, 1.71± 0.15 and 2.49±0.06; the herb layer, 0.33±0.13, 1.31±0.15 and 2.15±0.08; the bryophyte layer, 1.30±0.11, 2.08±0.04 and 1.73±0.11.) for the three habitats, respectively; Pielou index of the tree layer was 0.45±0.05, 0.29±0.06 and 0.28±0.08 (the shrub layer, 0.75±0.03, 0.68±0.05 and 0.52±0.06; the herb layer, 0.68±0.02, 0.77±0.02 and 0.74±0.02; the bryophyte layer, 0.40±0.03, 0.63±0.02 and 0.52±0.03.) for the three habitats, respectively. Simpson's index of the tree layer was 0.63±0.06, 0.78±0.04 and 0.83±0.07 (the shrub layer, 0.21±0.03、0.28±0.05、0.45±0.06; the herb layer, 0.25±0.02, 0.12±0.01 and 0.17±0.01; the bryophyte layer, 0.45±0.04, 0.18±0.01 and 0.31±0.04.) for the three habitats, respectively. There were low Sorenson index both in the tree layer and in the herb layer among the three habitats, whereas, high Sorenson index occurred both in the shrub layer and in the bryophyte layer. To sum up, there were differences both in community structure and plant diversity among the three different habitats, which means that we should pay more attention to habitats heterogeneities of the primitive Abies faxoniana forest when we take action to manage the forest in the Huanglong World Natural Heritage Site.

基于ITS 序列和matK 基因序列的中国药用石斛及其混伪品的分子鉴定

为了从分子水平对中国药用石斛及其混伪品进行鉴定，本文选取了核rDNA ITS 序列和叶绿体DNA 的matK 基因序列进行研究。采用改良的CTAB 法提取石斛的基因组DNA，PCR 产物直接测序法对17 种（共32 份）药用石斛的核糖体内转录间隔区ITS 全序列进行测定，克隆测序法对12 种（共22 份）药用石斛的叶绿体的matK 基因序列进行测定，运用BioEd it，MEGA4.0 等生物软件分析了石斛属植物的rDNA ITS 序列及叶绿体的matK 基因序列的特征，比较了石斛属间、种间、种内不同居群（品种）间的序列碱基差异及遗传距离，应用邻接法构建分子系统树。主要研究结果如下： （1）建立了17 种（共32 份）药用石斛rDNA ITS 区碱基全序列数据库，其中，ITS1 的长度为228~234 bp，GC 含量为45.7%~53.0%，变异位点167 个，占总位点67.34%，信息位点106 个，占总位点42.74%，ITS2 长度为241~247 bp，GC含量为44.8%~55.7%，变异位点165 个，占总位点66.27%，信息位点115 个，占总位点46.18%。 （2）建立了12 种（共22 份）药用石斛的叶绿体matK 基因全序列数据库，叶绿体matK 基因长1410 bp，变异位点51 个，信息位点11 个。除了存在碱基替换的遗传变异外，还存在碱基的插入和缺失。 （3）通过ITS 序列比较分析了各材料间的遗传距离和碱基差异，属间的遗传距离为0.295，石斛种间的平均遗传距离为0.142，碱基相差2~156 个，种内各居群间的平均遗传距离为0.002，碱基相差1~2 个。属间的遗传距离大于种间的遗传距离，种间的遗传距离大于种内不同居群（品种）间的遗传距离。 （4）根据分析石斛叶绿体的matK 基因序列得到，外类群（密花石豆兰）与石斛属间最小遗传距离为0.027，石斛种间的平均遗传距离为0.008，种间最大的遗传距离0.014， 最小的遗传距离为0.003，碱基相差8~20 个。种内不同居群（品种）遗传距离为0.001，相差1~5 个碱基。 （5）利用17 种石斛的全序列数据库及遗传分析软件，通过对待检种rDNA I TS区进行序列测定，成功地对10 个待检种进行了鉴定，并且在原植物开花后得到了验证。 （6）运用12 种石斛的matK 基因全序列数据库及遗传分析软件，成功地对4个待检种进行了鉴定，同样在原植物开花后得到了验证。 （7）本文利用石斛的核糖体内转录间隔区ITS 序列和叶绿体的matK 基因序列数据库分别构建了NJ 树，外类群与石斛属间石斛种间以及种内不同居群（品种）间均能在NJ 树中明显分化开来，二者构建的分子系统树一致，为石斛的分子鉴定提供了依据。 In order to identify Chinese Herba Dendrobii and its adulterant species on molecular level, we studied the sequences of rDNA ITS and chloroplast matK gene. Genomic DNA of Dendrobium was extracted using the modified cetyltrimethyl ammonium bromide (CTAB) method. The PCR products of the rDNA ITS sequences of Dendrobium (32 materia ls) were purified and then sequenced. The PCR products of chloroplast matK gene of Dendrobium (22 materia ls) were purified, cloned and then sequenced. The characteristic of the sequences and the genetic dista nce were compared between Bulbophyllum odoratissimum and Dendrobium, Dendrobium interspecies, and different populations. Phylogenetic trees were constructed using the NJ method by the biology softwares including BioEd it, MEGA4.0 etc. The ma in results as follows: (1) It was built up that the database of rDNA ITS sequences of 17 species of Herba Dendrobii (32 materia ls). The ITS1 was 228~234 bp, the GC content accounting for 45.7%~53.0%. Its variable sites were 167, accounting for 67.34%. The Parsim-Informative positions were 106, accounting for 42.74%. The ITS2 was 241~247 bp, the GC accounting for 44.8%~55.7%. The variable sites were 165, accounting for 66.27%. The Parsim-Informative positions were 115, accounting for 46.18%. (2) The database of the chloroplast matK gene sequences was built up, which contained 12 species of Herba Dendrobii (22 materia ls). The matK gene sequences were about 1410bp in length. There were 51 variable sites and 11 Parsim-Informative sites. And there were nucleotides insertions and deletions in some species , in addition to the nucleotides substitutions. (3) The rDNA ITS sequences were compared and analyzed by the biology softwares. The genetic dista nce between Bulbophyllum odoratissimum and Dendrobium was 0.295. The avera ge genetic dista nce was 0.142 between Dendrobium species, and there were 2~156 variable nucleotides. The avera ge genetic dista nce between different populations was 0.002, and there were 2~156 variable nucleotides. The genetic dista nce between Bulbophyllum odoratissimum and Dendrobium was greater tha n that of Denrobium interspecies. Meanwhile, the genetic dista nce between Denrobium species was also greater tha n that of different populations (variaties). (4) The characteristics of the chloroplast matK gene sequences were obtained after analyzing by the biology softwares. The minima l genetic dista nce was 0.027 between Bulbophyllum odoratissimum and Dendrobium . The ma xima l genetic dista nce was 0.014 between Dendrobium species, and there were 20 variable nucleotides. The minima l genetic dista nce between populations was 0.003, and there were 8 variable nucleotides.The genetic dista nce between populations was 0.001, and there were 1~5 variable nucleotides. (5) The molecular Phylogeny tree was constructed on the database of rDNA ITS the sequences of 17 species of Herba Dendrobii using the biology softwares. Then we authenticated 10 materia ls on molecular level. What’s more, they had been proved when these pla nts flowered. (6) The molecular Phylogeny tree was built up on the database of chloroplast matK gene sequences of 12 species of Herba Dendrobii with the biology softwares.Then 4 materia ls were authenticated on molecular level. Moreover, they had also been proved when these pla nts were in flower. (7) The Phylogenetic trees were separately constructed on the sequences of rDNA ITS and chloroplast matK gene B. odoratissimum and Dendrobium all could be distinguished on the Phylogenetic trees. Meanwhile, the Phylogenetic trees based on two groups of sequences were coincident. rDNA ITS and matK gene sequence could be used as molecular markers for authentication of Herba Dendrobii.

低剂量~(12)C~(6+)离子束预辐照对小鼠肝脏细胞DNA损伤和周期进程的影响

研究低剂量重离子束预辐照对小鼠肝脏辐射损伤程度的影响。分别用低剂量12C6+离子束全身均匀预辐照处理小鼠,剂量分别为0、0.05、0.1、0.25、0.5Gy,剂量率为1Gy/min,4h后用4Gy的12C6+离子束全身均匀辐照,照射8h后用流式细胞仪检测辐照小鼠肝脏细胞在各细胞周期时相的百分率,并用单细胞电泳技术检测辐照损伤小鼠肝脏细胞的DNA损伤程度。结果显示,和对照组相比,低剂量预辐射处理可以减轻辐照损伤小鼠肝脏细胞G0/G1期和G2/M的阻滞,促进肝脏细胞在S期的积累。此外,辐照小鼠肝脏细胞的拖尾率及拖尾长度也显著减少,其中以0.1Gy处理组效果最为显著(P<0.01)。提示:低剂量重离子预辐照能使细胞产生适应性反应,有效减轻辐照小鼠肝脏细胞G0/G1期和G2/M的阻滞,并显著减轻肝脏细胞DNA的辐射损伤程度。