青杨(Populus cathayana Rehd.)对逆境胁迫的反应及lea基因的表达分析

杨树具有分布广、适应性强，在生态环境治理和解决木材短缺方面均占有重要位置。青杨(Populus cathayana Rehd.)是青杨派树种的重要成员之一，也是我国的特有种。本研究通过对不同水分梯度的干旱胁迫下青杨形态和生理生化的反应，不同pH值盐碱胁迫下不同海拔和不同气候地区的四个青杨种群在生理生态上的反应差异，以及在干旱和低温胁迫下青杨lea2, lea3组基因表达差异的研究，从形态、生理、生化和分子生物学水平系统地研究了青杨在不同逆境胁迫下的反应和青杨不同种群在盐碱胁迫下的反应差异。主要研究结果如下： 1. 青杨在干旱胁迫下的反应机制：中度和重度干旱胁迫下植株的生长受到明显抑制。表现在光合系统上青杨的净光合同化速率(A)下降，主要原因是气孔导度(gs)，胞间二氧化碳浓度(Ci)下降。另外最大量子产量(Fv/Fm)、光化学猝灭效率(qP)降低反应了干旱胁迫下光合系统II(PSII)受到严重损伤, 而且非光化学猝灭效率(qN)上升，导致可利用化学能产量下降，叶绿体产生淀粉的量减少。qP降低qN上升导致产生的过量电子对光合系统的伤害造成活性氧以及丙二醛(MDA)的含量增加。超微解剖结构显示，干旱胁迫增强时，叶绿体内淀粉粒的数目减少，而且叶绿体、线粒体等细胞器中嗜锇颗粒的数目增加。为清除细胞内的活性氧，植物一般的反应是抗氧化系统酶活性增加，对青杨来讲超氧化物歧化酶(SOD), 抗坏血酸过氧化物酶(APx)活性的增加远大于过氧化物酶(POD)，这显示了在青杨中SOD、APx酶在清除活性氧的作用上大于POD。另外同工酶研究结果显示这些酶活性的升高主要是由于各条同工酶带表达量的增加，而不是诱导新酶带的产生。另外，75% FC水分处理下有些指标非但没有下降，像A和有效光量子产量(Y)的值都略有增加，而且gs同时增加。另外，100% FC比75% FC细胞内淀粉粒的数目少一些，但有少量的嗜锇颗粒。这证明100% FC土壤水分也许并非最适合青杨生长。 2. 盐碱胁迫对不同海拔地区青杨种群的反应差异：青杨高海拔和低海拔种群的各种生理特性随着pH值上升都受到了很大的影响。两种群叶和根中Na+、K+ 含量, Na+/K+比率随着pH值的上升影响显著。在pH值高于10.4时高海拔种群叶和根中Na+/K+比率急剧下降但是低海拔种群中却一直维持在较高水平。两种群中MDA、脯氨酸(Proline)的含量，抗氧化系统酶的活性都受到了严重的影响，证明两个种群都属于盐碱胁迫敏感类型但是高海拔的种群对盐碱胁迫的耐性要高于低海拔。这主要是由于高海拔种群一般具有耐干旱、低温胁迫的能力，而植物的抗逆机制一般都有共通之处。 3. 盐碱胁迫对不同气候地区青杨种群的反应差异：盐碱胁迫下两种群的光合作用受到明显的抑制，具体表现在叶绿素的含量和A 显著下降。净光合速率的下降主要是由于叶片gs，Ci 值降低引起的。与湿润地区的种群相比盐碱胁迫增强时，干旱地区的种群叶绿素含量和光合能力的升高与K+离子含量增加有关。植物维持细胞质高K+/Na+值对植物的抗盐性有很重要的作用。为清除盐碱胁迫产生的活性氧，抗氧化系统酶活性增加。盐碱胁迫下干旱地区的种群在SOD、CAT 和谷胱甘肽还原酶(GR)等酶的活性均显著上升，而湿润地区种群只有谷胱甘肽氧化酶(GST)的活性明显增加，说明干旱种群的抗氧化酶系统在较高盐碱胁迫下的保护作用要强于湿润种群。这主要是由于植物抗盐碱胁迫与抗干旱胁迫在一些方面的机制是一致的，抗旱种群一般也能抵抗一定程度的盐碱胁迫。 4. 青杨lea2、lea3 基因在干旱和低温胁迫下的表达差异：通过荧光定量PCR 分析，lea2、lea3 组基因在干旱和低温胁迫下在mRNA 水平的瞬时表达量明显升高，说明了两基因在青杨耐干旱和低温胁迫上都起显著的作用。而且两基因在干旱胁迫下，表达量的升高和降低的时间近乎同步，表明两基因在干旱胁迫下对植物应急保护机制的启动都发挥着重要的作用。低温胁迫下lea3 基因在mRNA 水平上表达量显著上升的时间要早于lea2，而且lea3 基因的持续作用时间明显长于lea2 组基因，说明了低温胁迫开始时lea3基因在植物应对逆境的作用上要大于lea2 基因。 Poplars play an important role in lumber supply, and are important components of ecosystems due to their wide distribution and well adaptation. Populus cathayana Rehd., which belongs to Populus Sect. Tacamahaca Spach, is one of the most important resources of poplars and is specialist to china. In this study, different altitudes and climates populations of P. cathayana were used as experiment materials to investigate the adaptability to drought and salt-alkali stresses. And the cultures of P. cathayana were used to analyze the lea2 and 3 group genes expression when exposed to drought and low temperature stresses. The results are as follows: 1. A large set of parallel responses to drought stress: Drought stress caused pronounced growth inhibition. A decreased significantly and was mainly the result of gs and Ci down. Besides, Fv/Fm, qP decreased and that reflected the harmful effects to PSII of drought stress. In accordance with qN increasing, decreased useful energy production caused the starch numbers reduction in chloroplast. The qP up and qN down improved the levels of ROS and MDA. Starch numbers in chloroplast reduced and plastoglobuli numbers increased when soil water content decreased. To reduce ROS, the activities of SOD, APX, CAT and PPO were activated. The isozymes results show that the rising activities of the antioxidant enzymes resulted from certain isoform content increased, and not from the new band produced. Interestingly, morphological results show 100%FC maybe wasn’t the favorite water content for P. cathayana growth. 2. Effect of salt-alkali stress on morphological and physiological changes in two different altitudes populations of P. cathayana: We compared the physiological responses of two populations of Populus cathayana Rehder, originating from altitudes 2,840 m and 1,450 m. Our results demonstated that Na+ and K+ contents, and Na+/K+ ratios in leaves and roots are greatly affected by pH values. At pH 10.4, the Na+/K+ ratios in both leaves and roots sharply dropped in the higher altitude population but were always maintained at higher levels in the lower altitude population. The pH values causing maximum malondialdehyde (MDA) level, free proline content and antioxidant enzyme activities were significantly different in two populations. These results indicated that the higher altitude population exhibits greater tolerance to alkalinity stress than does the lower altitude population. 3. Morphological and physiological changes in two different climates populations of P. cathayana when exposed to salt-alkali stress. Salt-alkali stress caused pronounced inhibition of the growth and especially in photosystem. Pigments content and A decreased significantly and at the same time gs and Ci decreased too. Compared with wet climate population, the Chlorophyll content and A increased in drought climate population as pH value rising was related to the K+ content increasing. It is important to resist salt-alkali stress that the K+/Na+ ratio matained at high level in cytoplasm. To reduce ROS content, the SOD, CAT and GR activities rised significantly in drought population but only GST increased in wet population. The drought population showed higher salt-alkali tolerance than the wet population mainly resulted from the fact that drought tolerance was in accordance with salt-alkali tolerance to some extent. 4. The different expressional model of lea2 and lea3 gene when P. cathayana was exposed to drought and cold stress. RT-PCR results show both lea2 and lea3 suddenly expressed significantly in mRNA level under drought and cold stress. The expression level of two genes reached optimal level at the same time. But under cold stress, the earlier significantly rising expressional time and the longer maintained higher level time in lea3 than lea2 elucidated that lea3 may be more important than lea2 in resisting cold stress in short time in P. cathayana.

a dependable, scalable maintenance scheme for stateful license in drm

Natl Tech Univ Ukraine, Huazhong Univ Sci & Technol, Huazhong Normal Univ, Wuhan Univ, Ternopil Natl Econ Univ, IEEE Ukraine Sect, I&M CI Joint Chapter

the study of trustworthy software process improvement model

Huazhong Univ Sci & Technol, Natl Tech Univ Ukraine, Huazhong Normal Univ, Harbin Inst Technol, IEEE Ukraine Sect, I& M/CI Joint Chapter

a state-adaptive access control model for web-based idrs system

Huazhong Univ Sci & Technol, Natl Tech Univ Ukraine, Huazhong Normal Univ, Harbin Inst Technol, IEEE Ukraine Sect, I& M/CI Joint Chapter

remote attestation for custom-built software

Huazhong Univ Sci & Technol, Natl Tech Univ Ukraine, Huazhong Normal Univ, Harbin Inst Technol, IEEE Ukraine Sect, I& M/CI Joint Chapter

虎耳草属山羊臭组的界定和系统发育：核糖体DNA ITS序列证据

虎耳草属Saxifraga山羊臭组sect.Ciliatae是该属中最大的一个组，共有175种，主要分布在喜马拉雅地区，我国分布有166种，占总种数的95%；其中，112种为中国特有。约80%的种类分布在我国青藏高原和西南地区，是中国喜马拉雅植物成分的代表类群。山羊臭组内物种分化十分显著，分类处理也很困难，该组是否为单系类群，组下的系统发育关系也不清楚，均需进一步验证。本文测定了虎耳草属山羊臭组及其他组33种植物样品的核糖体DNA内转录间隔区ITS序列，并从GenBank调取虎耳草组sect.Saxifraga等组和近缘属唢呐草属Mitella共22种植物的该序列。ITS分析结果表明：（1）所研究的山羊臭组类群聚为单独一支，而且与垫状组sect.Porphyrion、虎耳草组、球茎组sect.Mesogyne和仅在欧洲分布的sect.Cymbalaria和sect.Cotylea等8个组聚成的另一分支构成姊妹群；（2）根据形态特征建立的山羊臭组的3个亚组即唐古拉亚组subsect.Hirculoideae、莲座状亚组subsect.Rosulares和具芽亚组subsect.Gemmiparae各自聚为一支，但是莲座状亚组这一支的支持率较低。同时，山羊臭组的鞭匐枝亚组subsect.Flagellares和subsect.Hemisphaericae的代表类群单独聚为一支，位于具芽亚组类群分支内部而不能成立；（3）唐古拉亚组和莲座状亚组又聚为一亚分支与具芽亚组构成姊妹群，而且具芽亚组最早从山羊臭组这一支中分化出来。我们的研究还发现山羊臭组内种间形态分化较大，而ITS碱基变异较小，这可能是山羊臭组类群在青藏高原及毗邻地区的高山环境下物种快速分化的结果。

国产赖草属的叶表皮特征与组群划分

对国产赖草属15个种的叶片表皮进行了光镜观察,发现下表皮呈现的微形态差异可以把国产类群划分为3个群体,并参照各群体所具的外部形态特征,3个群体应分别属于前人组群划分中的3个组,即多穗组(sect.Leymus)、少穗组(sect.Aphanoneuron(Nevski)Tzvelev)和单穗组(sect.Anisopyrum(Griseb.)Tzvelev).同时,根据叶表皮性状的递变趋势,分析了3个国产组的亲缘关系.结果表明:多穗组最原始,单穗组最高级,少穗组演化居中;单穗组与少穗组亲缘关系直接,与多穗组关系间接.

点地梅属的分子系统学、生物地理学和垫状形态的趋同进化

报道了青藏高原地区的点地梅属Androsace L.及羽叶点地梅属Pomatosace Maxim.共14种29个居群的ITS与trnL-F DNA序列各27与25条;并结合已报道相关种类的有关序列,构建了"点地梅群"的分子系统发育树.研究发现"点地梅群"的4个属为一单系类群,含有两个稳定的分支:一支全部由点地梅属的种类组成,另一支分别由羽叶点地梅属、Douglasia Lindley、Vitaliana Sesler和9种点地梅属植物组成;点地梅属裂叶组sect. Samuelia Schlechtd.的3个种与点地梅组sect. Androsace的2个种在3套序列分析中位于不同的系统位置.各分支基部的种都分布在中国东南部及青藏高原东部,分子地理标记的结果支持形态学提出该地区为"点地梅群"植物起源地的假设.从青藏高原东部地区向欧洲及其他北半球地区存在不同时期内多个进化支的多次扩散.粗略的时间估算表明该群植物可能是在第三纪的中新世以来才开始发生的.垫状种类分别在青藏高原和欧洲独立起源,而在青藏高原地区的分化要早于在欧洲的分化,在前一地区可能与青藏高原自中新世开始发生的造山运动、形成高海拔的山地有关,而在后一地区则是与第三纪末至第四纪的冰期气候反复波动有关.垫状植物在青藏高原上的大规模分布则可能较晚,与冰期结束后全新世晚期气候再次变冷有关.一些物种种

利用叶绿体DNA trn L-F序列初步探讨菊科风毛菊属的系统发育

风毛菊属Saussurea DC．是菊科物种分化十分剧烈和分类处理十分困难的一个属。该属的单系起源性质、属下分类系统以及一些独特形态物种的系统位置尚不清楚，有待进一步验证。本文测定了代表该属5个亚属37种植物43个样品和川木香属Dolomiaea DC．的1种样品的叶绿体DNA trnL-F序列，并调取菜蓟族Cardueae Cass．与风毛菊属具有一定亲缘关系的13属的该序列，一起进行了分支分析，重点验证该属的属下形态分类系统以及形态特殊、青藏高原地区特有的雪兔子亚属subgen．Eriocoryne中假雪兔子组sect．Pseudoeriocoryne的单系性质。研究结果表明：(1)尽管风毛菊属5个亚属形态变异极大，但种间的trnL-F碱基变异却非常小；(2)根据形态学划分的5个亚属在分支图上没有得到分辨；(3)根据无明显茎、叶呈莲座状包被头状花序等特征建立的假雪兔子组是一多系群，与其他雪兔子亚属的种类也没有密切的亲缘关系，其共同拥有的形态学特征分别起源了4次；(4)雪莲亚属假雪莲组subgen．Amphi- laena sect．Pseudoamphilaena中的多鞘雪莲s．polycolea变种尖苞雪莲S．polycolea var．acuisauama与风毛菊亚属subgen．Saussurea的长毛风毛菊S．hieraciodies、美丽风毛菊s．superba、打箭风毛菊s．tatsienensis和重齿风毛菊s．katochaete具有一段长18个碱基的插入，但多鞘雪莲原变种和重齿风毛菊另一居群无此插入；这一插入在整个菜蓟族和风毛菊属中都十分特殊，是一次进化事件的结果，这一复合体的形态分化应该是在这一进化事件发生之后进行的；而尖苞雪莲和重齿风毛菊拥有这一特殊序列可能是由于杂交而导致种内存在不同的单倍性。研究结果证实青藏高原极端环境下即使在较低的分类等级——属内、种问的形态特征也存在相同选择压力下的生态趋同进化。这一点在利用形态特征研究该地区物种的亲缘关系和命名自然分类等级时应予以特别重视。风毛菊属提供了研究极端环境下物种快速分化、网状进化和趋同进化的典型范例。

条纹龙胆的胚胎学研究(英文)

首次报道了条纹龙胆(Gentiana striata Maxim.) 的胚胎学特征, 研究结果用以讨论龙胆属狭蕊组(Gentiana Sect.Stenogyne) 的系统演化关系。主要研究结果如下: 花药四室; 药壁发育为双子叶型; 绒毡层细胞仅来源于初生壁细胞, 故绒毡层起源属单型起源, 细胞具单核,原位退化, 属腺质型绒毡层, 药隔处的绒毡层细胞经多次平周分裂形成2 层至多层的绒毡层细胞, 其余部位的绒毡层细胞仍为1 层细胞; 中层细胞1 层；在花药成熟时, 花药的表皮细胞和药室内壁均部分纤维状加厚且柱状伸长。小孢子母细胞减数分裂为同时型, 四分体的排列主要为四面体形；成熟花粉为32细胞型。子房为2心皮, 1室, 侧膜胎座。胚珠4列。薄珠心,单珠被, 珠心基部产生珠被原基, 进而形成珠被, 条纹龙胆仅有1 层珠被。珠被沿珠心向上生长并将珠心包围, 于胚珠顶部形成珠孔。胚珠在发育过程中, 整个胚珠的本体倒转, 而且珠柄继续生长并弯曲, 使珠孔与合点端的连线与珠柄垂直, 形成Hypertropous 胚珠。大孢子母细胞减数分裂形成的4 个大孢子呈直列式排列, 合点端的大孢子具功能。胚囊发育为蓼型。极核在受精前融合为次生核, 反足细胞3 个、多宿存。雄蕊先熟。珠孔受精。胚乳发育为核型。胚胎发育为茄型酸浆Ⅱ变型。通过比较龙胆属狭蕊组与龙胆属其它组和双蝴蝶属的胚胎学特征表明, 龙胆属狭蕊组在一些重要的胚胎学特征上与双蝴蝶属较相似, 而与龙胆属其它组存在较大差异, 故建议应将龙胆属狭蕊组从龙胆属中移出。

青藏高原毛茛科3种特有植物核型和进化研究

对青藏高原高山冰缘地区毛茛科3 种特有植物的核型进行了分析。它们的核型公式(K)、染色体相对长度组成(C. R. L. ) 和核型不对称系数(A s. K% ) 分别为: 青藏金莲花 T rollius pumilus var. tangu ticus: K (2n) = 6m + 8sm (2SA T ) + 2st, C. R. L. = 4L + 4M 2+ 4M 1+ 4S,A s. K% = 63. 57, 核型属2B型; 甘青乌头A conitum tanguticum 为K (2n) = 6m + 10sm ,C. R. L. = 4L + 8M 1+ 4S,A s. K% = 62. 54, 2B 型; 单花翠雀花Delphinium candelabrum var.monanthum 为K (2n) = 6m + 8sm + 2st, C. R. L. = 4L + 4M 2+ 4M 1+ 6S,A s. K% = 64. 34, 属3B 型。经同相关近缘种核型资料比较, 青藏金莲花核型不对称性和进化程度比金莲花T.ch inensis 低; 甘青乌头的核型不对称性和进化程度在其近缘类群(乌头组Sect. Aconitum ) 已报道的种之内最低; 单花翠雀花核型不对称性和进化水平比翠雀组(Sect. Delphinastrum ) 已报道的展毛翠雀花D. kamaoense var. glabrescens、多枝翠雀花D. maxim owiczii 和蓝翠雀花D. caeruleum 都低。这与该3 种植物在王文采先生(1979) 中国毛茛分类系统中的位置是一致的。

鬼灯檠属的系统发育、分类和地理分布

本文对鬼灯檠属Rodgersia Gray的染色体数、花粉体积和纹饰、萼片数目、萼片脉序和脉型、萼片腹面毛被、花梗和花序轴毛被、叶的类型等关键性状进行了分析,确定了其进化顺序;依据性状的系统发生,绘制了鬼灯檠属的瓦格勒尔系统树;确认本属有5种和3变种,其中以R.podophylla为最原始, R.nepalensis为最进化,而R.aesculifolia,R.sambucifolia和R.pinnata则居于两者之间。本属分两组Sect.Rodgersia,仅含R.podophylla;Sect.Sambuclfolia J.T.Pan,含R.aesculifolia,R.sambucifolia,R.pinnata,R.nepalensis。依据种的主要分布区,划本属植物为4个分布类型,即:日本-朝鲜间断分布,秦岭-大巴山分布,横断山分布和东喜马拉雅分布。笔者认为, 本属的起源地在日本一朝鲜一带, 横断山地区是其现代分布中心和分化中心本属的散布路线是自日本一朝鲜, 经秦岭一大巴山, 通过横断山地区而进入东喜马拉雅本属的起源时间, 当在晚第三纪以前晚白要世至早第三纪。此外, 还报道了鬼灯集属植物的花粉形态。

橐吾属的起源、演化与地理分布

橐吾属Ligularia Cass.是菊科千里光族款冬亚族的一个大属。在款冬亚族中本属与大吾风草属Farfugium Lindl.亲缘关系最近,但进化程度较高。本属包括6组、11系129种。所有种类均分布在亚洲,仅2种扩散至欧洲。在东亚地区有119种,占该属总种数的96％。高度集中在横断山区的有4组、6系67种,其中61种为特有种,占该属总组数的66％,总系数的54.5％,总种数的52％。这个事实表明了横断山区是该属的多度中心和多样化中心。通过性状分析,伞房组伞房系Sect.Corymbosae,Ser.Calthifoliae叶肾形,具掌状叶脉,头状花序大而少,排列呈伞房状,总苞半球形,被认为是该属的原始类群。原始种齿叶橐吾L.dentata和鹿蹄橐吾L.hodgsonii的分布区从我国四川东部经过湖北、湖南、安徽、福建等省至日本。这个分布格局与近缘属...

Two new species of Saxifraga (Saxifragaceae) from Southwestern China

Two new species, Saxifraga xiaozhongdianensis J. T. Pan and S. ludingensis J. T. Pan, from the Saxifragaceae in China are described and illustrated. Of these, S. xiaozhongdianensis is endemic to Zhongdian, Yunnan, and is related to S. brachyphylla Franchet. It differs from S. brachyphylla in the sepals adaxially dark brown glandular-villose and the petals basally subauriculate. Saxifraga ludingensis occurs in Luding, Sichuan, and is very similar to S. egregioides J. T. Pan and S. stellariifolia Franchet. It differs from S. egregioides in the stems brown glandular-villose, the cauline leaves adaxially brown glandular-villose, the sepals spreading in anthesis and abaxially brown glandular-villose, and the petals 5-veined. It differs from S. stellariifolia in the leaves cordate and abaxially glabrous, the sepals abaxially brown glandular-villose, and the petals 4-callose and 5-veined. Saxifraga xiaozhongdianensis and S. ludingeasis are apparently endemic to western China and belong to Saxifraga sect. Ciliatae Haworth, emend. J. T. Pan.

Origin of the Qinghai-Tibetan Plateau endemic Milula (Liliaceae): further insights from karyological comparisons with Allium

Milula, a monotypic genus endemic to the Qinghai-Tibetan Plateau, was found to be nested deeply within Allium by the molecular phylogeny despite the aberrant morphology. It remains unknown what had contributed to the rapid evolution of morphology and origin of this exceptional species. In contrast to a previous report of its karyotypes with 2n = 16 = 8M+8SM (2SAT), similar to most species of Allium, a rather different karyotype, 2n = 20 = 4M +10SM+6T (2SAT), was found in examined 31 individuals from 6 populations of M. spicata distributed in the central Tibet. Karyotypes of 7 Allium species occurring in the Qinghai-Tibetan Plateau were further reported. The basic number x = 8 was confirmed for all of them and their karyotypes consist mainly of metacentric and submetacentric chromosomes with rare subterminal and terminal chromosomes. The karyotype of M. spicata is distinctly different from that of most Allium species occurring in the plateau through a complete comparison of all available species in this region and adjacent areas. However, the same chromosome number and similar karyotypic structure were found in A. fasciculatum of Sect. Bromatorrhiza, indicating a possible close relationship between them. But this similarity is contradictory to the preliminary molecular phylogenetic analysis that Milula was closely related to A. cyathophorum of Sect. Bromatorrhiza with x=8, but the other species with x=10 and 11 in this section were clearly placed in the other clade. We therefore suggested that the paralleling evolution from x=8 to x=9, 10 and 11 with increasing asymmetry of karyotype possibly due to the chromosomal Robertsonian translocation might occur separately in the two recognized phylogenetic lineages of Allium. In addition to aneuploidy and following change of the chromosomal structures, the habitat isolation due to the recent uplift of the Qinghai-Tibetan Plateau and the Quaternary climatic oscillation, plays a greater role in origin of Milula and other endemic species (genera) with aberrant morphology from their progenitors.