南方红豆杉(Taxus Chinensis Var.Mairei)叶片膜保护系统与温度的关系

以缙云山麓的南方红豆杉为材料 ,研究了其叶片低温半致死温度及膜保护系统随气温下降的变化 .结果表明 ,低温半致死温度降低的同时 ,SOD、POX活性增强 ,VC 含量增加 ,使膜保护系统清除活性氧的能力加强 ,O2· - 水平降低 ,MDA含量下降 。

Effects of Piriformospora indica on the Respiration of Taxus chinensis var.mairei under Water Stress

Seedlings of Taxus chinensis var.mairei were used as experimental materials to study the adaptation of Piriformospora indica to this plant under water stress.The materials were divided into two groups,namely,with or without inoculation with P.indica.Each group was subjected to four different levels of water stress.Vitality and physiological and biochemical indexes of the roots of T.chinensis var.mairei were regularly measured.Under water stress,T.chinensis var.mairei had significantly decreased root vitality;root vitality was higher in inoculated roots than in uninoculated roots.Under intense water stress,the inoculated roots had a higher soluble sugar content than the uninoculated roots.Under water stress,T.chinensis var.mairei experienced decreased activity of aerobic respiratory metabolic enzymes.The activity of anaerobic respiratory metabolic enzymes and alcohol dehydrogenase initially increased and then decreased,whereas that of lactate dehydrogenase increased.The inoculated roots had a higher activity of respiratory metabolic enzymes than the uninoculated roots.As water stress was further intensified,the roots had significantly decreased activity of aerobic respiratory metabolic enzymes and significantly increased activity of anaerobic respiratory metabolic enzymes.The activity of respiratory metabolic enzymes decreased faster in the uninoculated roots than in the inoculated roots.This study demonstrated that Piriformospora indica plays a positive role in enhancing the antihypoxic ability of T.chinensis var.mairei,thereby alleviating plant damage due to water stress.

Improved Production of Paclitaxel from Suspension Culture of Taxus chinensis var. mairei by in situ Extraction with Organic Solvents

The production of paclitaxel from suspension culture of Taxus chinensis var,mairei was improved by in situ extraction with organic solvents to avoid feedback repression and product degradation.Oleic acid and dibutyl phthalate were proved to be suitable solvents .The optimal volumetric percentage of organic solvents in the culture medium was found to be around 8%,and the favorable time for their introduction was at the exponential phase of cell growth,Paclitaxel production with the in situ extraction was ca 3-fold of that without extraction.

Dynamic Effects of Cerium on Syntheses of Soluble Protein and Taxol in Suspension Culture of Taxus Chinensis Var. Mairei Cells

The dynamic effects of Ce4+ on the syntheses of soluble protein and taxol in suspension cultures of Taxus chinensis var. mairei cells were studied. The phenomena of 'partition' and 'bifurcation' were observed in studying the dynamic effect of Ce4+ on soluble protein synthesis and cell activity. That is, Ce4+ of low concentration improves the soluble protein synthetic strength and cell activity, while Ce4+ of high concentration is harmful to protein synthesis and cell activity. In addition, Ce4+ of appropriate concentration enhances taxol synthesis.

Comparison of Morphological and Anatomical Characteristics of Taxus chinensis var.mairei Seedlings Root under Waterlogging Stress in Different Substrates

Four different ratios of river sand,ceramic pellets,vermiculite and perlite(1:1),and field soil were selected as the substrates in this experiment,and four gradient levels of root waterlogging,half waterlogging,full waterlogging and normal were set to investigate the effects of different gradients of waterlogging stress on the root morphology of Taxus chinensis var.mairei seedlings under different substrates.In this study,the root anatomical structure of Taxus chinensis var.mairei under different waterlogging stress was observed by the paraffin section method.The roots of T.chinensis var.mairei were diarch,with no pith and resin canals.There was a large number of tannins in the pericycle of the aerial adventitious roots of seedlings adapted to waterlogging.Also,the endodermis has obvious casparian strip thickening,and there were 4-5 layers of large parenchymatous cells in the close to the inner side of the pericycle in the vascular cylinder,which could increase the storage capacity,and transport capacity of the root.Under the treatment of root waterlogging stress,the development of plant roots in the mixed substrate of vermiculite and,perlite was the earliest.Under half waterlogging stress,T.chinensis var.mairei seedlings treated with various substrates all could better adapt to the environment of waterlogging stress.Under the stress of fully waterlogging,the roots of seedlings planted in river sand substrate developed secondary growth.

Microsatellite loci from Taxus chinensis var. mairei (Taxaceae), an endangered and economically important tree species in China

Taxus chinensis var.mairei is an endangered and economically important tree species in China.Four polymorphic microsatellite markers were developed and characterized using the fast isolation by amplified fragment length polymorphism(AFLP)of sequences containing repeats(FIASCO)protocol.Polymorphism of each locus was quantified for five natural populations from Hubei Province,China.The number of alleles per locus varied from 6 to 24.The ranges of observed and expected heterozygosity were 0.493–1.000 and 0.440–0.845,respectively.These are the first microsatellites reported for the family of Taxaceae and will be helpful for the ongoing population and conservation genetics research of Taxus chinensis var.mairei.

濒危植物南方红豆杉种群生命表及谱分析

Based on the investigation in Longxi Mountain National Nature Reserve and the theory of survival analysis,a static life table of Taxus chinensis var. mairei population was worked out,the curves of its survival rate,mortality rate and killing power were drawn,and the population dynamics was analyzed by spectral analysis.The results showed that the survival curve of the population appeared to be a type of Deevey Ⅲ,and the high mortality of seeding was one of the important reasons which caused Taxus chinensis var. mairei to be endangered.The spectral analysis of the population showed that there was a marked periodic regularity in the process of natural regeneration of Taxus chinensis var. mairei .

红豆杉愈伤组织培养中褐变现象的初探

多酚氧化酶 (PPO)和过氧化物酶 (PO)的活性高低与红豆杉愈伤组织的褐变程度有着密切关系 ,即酶活性高 ,愈伤组织褐变严重 .通过在培养基中添加适量的Vc、活性炭、CA、GA3 和ABA等物质 ,能抑制酶的活性 ,减轻褐变程度 。

光胁迫对南方红豆杉叶片中叶绿体色素和紫杉醇含量的影响

研究了在光胁迫下南方红豆杉叶片中叶绿体色素含量和紫杉醇含量的动态变化。结果表明,与对照相比,叶绿素a、叶绿素b和总叶绿素的含量以及叶绿素a/叶绿素b比值在光胁迫下均减少,随胁迫时间的延长,叶绿素a、叶绿素b和总叶绿素的含量逐渐上升,叶绿素a与叶绿素b的比值先上升后下降;类胡萝卜素含量在前两周与对照相比降低,2周后高于对照;类胡萝卜素与叶绿素的比值高于对照,随胁迫时间的延长,其趋势先降低后上升。光胁迫处理后,南方红豆杉叶片中紫杉醇含量与对照相比,在第1周时略有下降,而后随胁迫时间的延长,紫杉醇含量在第2周开始迅速大量积累,而在处理3周时达到较高值,已增加到1.5倍,这对提高人工种植的南方红豆杉中紫杉醇含量具有非常重要的意义。

濒危植物南方红豆杉遗传多样性的RAPD分析

采用RAPD技术检测了山西南部南方红豆杉8个种群的遗传多样性。利用21个10聚寡核苷酸引物共检测出134个位点,其中多态性位点123个,占91.79%,8个种群的遗传多态位点百分率分别为67.16%(红豆峡)、67.91%(凤凰谷)、66.42%(小梯河)、66.42%(蟒河)、50.75%(历山西峡)、43.28%(云蒙山)、78.36%(长治宾馆)、50.75%(磨河)。南方红豆杉的遗传多样性分析结果显示:Shannon指数为2.180,其中31.7%的遗传多样性来自种群间,68.3%来自种群内;Nei指数为0.571,种群间的遗传分化系数(Gst)为0.181。8个种群间的遗传相似性分析结果显示:壶关红豆峡和陵川凤凰谷种群间的遗传距离最小(0.1092),壶关红豆峡和陵川蟒河种群间遗传距离最大(0.55)。本研究结果揭示,南方红豆杉自然种群具有较高的遗传多样性,其遗传多样性不是导致该种群濒危的主要原因,导致南方红豆杉种群濒危的原因可能与南方红豆杉自然种群及群落所在生境的直接破坏及其本身生物学和生态学特性所导致的自然更新不良有着密切的联系。

南方红豆杉内生菌及紫杉烷类产物的初步鉴定

从南方红豆杉（Ｔａｘｕｓｃｈｉｎｅｎｓｉｓｖａｒｍａｉｒｅｉ）的主干和侧枝树皮及皮下部分，分离、筛选得到９１个纯化的微生物菌株．经过摇瓶培养和静止培养，再用二氯甲烷萃取抽提，抽提产物经以ｔａｘｏｌ、ｂａｃｃａｔｉｎⅢ和ｃｅｐｈａｌｏｍａｎｎｉｎｅ为标准对照的薄层层析分析，表明其中６个菌株能分泌紫杉烷类的化合物．分类鉴定的初步结果为头孢霉属。

遮荫对南方红豆杉光合特性及生活史型影响

对浙江省富阳市种植的5年生南方红豆杉,89%遮荫的条件下生长的南方红豆杉与46.4%遮荫及自然光条件诱导50天的南方红豆杉的光合特性、光合色素及其生活史型的研究。结果表明:89%遮荫、46.4%遮荫和自然光的光补偿点分别为18.88,30.52和65.34μmolm-2·s-1,光饱和点分别为287.01,258.25和358.92μmol·m-2·s-1,遮荫可以降低南方红豆杉的光补偿点和光饱和点,从而能够更好地利用弱光,同时提高光合速率,增强了南方红豆杉的光合能力,其中以89%遮荫的变化最明显。随着遮荫程度的增大,南方红豆杉叶片的叶绿素a、叶绿素b及类胡萝卜素等光合色素的含量均增大,叶绿素a与叶绿素b含量的比值减小,说明遮荫可以增加植物对光能的利用,尤其是增加了对蓝紫光的利用,提高了光合效能。研究还发现遮荫对南方红豆杉的生活史型有一定的影响,89%遮荫、46.4%和自然光的生活史型分别为V0.836C0.164,V0.625C0.375和V0.772C0.228,以89%遮荫的营养生长最为旺盛。因此,89%遮荫是这三种光照条件中南方红豆杉营养生长的最适条件。

南方红豆杉产紫杉醇内生真菌的分离鉴定

从南方红豆杉(Taxus chinensisvar.mairei)植株分离到内生真菌63株,其中24株经鉴定分属于19个种(属).真子囊菌纲的2个属2株,半知菌纲的14个属22株.真子囊菌纲的无毛毛壳属(Achaetomiumsp.)的1株为新发现种.半知菌纲的葡萄孢属(Botrytissp.)1株和无孢菌群(Mycelia sterlia)2株的培养液,经浓缩萃取,薄层层析检测,Rf值分别为0.404、0.404、0.401,与紫杉醇对照品Rf值一致,为南方红豆杉产紫杉醇内生真菌.

不同激素处理对南方红豆杉扦插苗的影响

以清水处理为对照,使用不同激素(ABT1号生根粉、NAA、IBA)处理南方红豆杉插穗,从而研究不同激素处理对南方红豆杉扦插苗生根率、生物量及紫杉醇含量的影响。结果表明:ABT处理下,南方红豆杉扦插苗的生根率、生根数、新生枝叶数以及紫杉醇的含量均为最高。因此,用ABT处理南方红豆杉插穗优于其他激素处理。

元宝山南方红豆杉种群分布格局及动态

采用相邻格子样方法取样数据 ,应用方差 /均值比的t检验法、负二项参数、格林指数、Cassie指标、扩散型指数、丛生指标、平均拥挤度和聚块性指数等方法及分布模型 ,研究了南方红豆杉种群的空间分布格局及其动态 .结果表明 ,南方红豆杉种群空间格局为集群分布 ,从幼苗到大树 ,其集群程度减小 。

胸径、构件和季节对南方红豆杉中紫杉醇和10-DAB含量的影响

系统采集了12个不同胸径的南方红豆杉当年生针叶和树皮样品,用超高效液相色谱(UPLC)测定其紫杉醇(taxol)和10-去乙酰基巴卡亭Ⅲ(10-deacetylbaccatin Ⅲ,10-DAB)含量,结果显示针叶的两种被测试物质含量的平均值分别为0.0127mg·g-1和0.0805mg·g-1,树皮的这两种物质含量平均值分别为0.1164mg·g-1和0.4842mg·g-1。当年生针叶、树皮中紫杉醇含量与胸径相关性不显著。对植株不同构件(枝条、针叶、树皮和根)中紫杉醇和10-DAB含量的测定表明,根中紫杉醇和10-DAB含量最高,当年生针叶紫杉醇含量最低。天然和人工栽培南方红豆杉当年生针叶中紫杉醇和10-DAB含量呈明显的季节变化,各月份间含量差异显著,人工栽培和天然植株针叶在生长速度明显减缓的10月份,紫杉醇和10-DAB含量均出现一个明显的峰值。

濒危植物南方红豆杉叶片形态结构及气孔参数

用光学显微镜观察了南方红豆杉叶片形态结构。结果表明：南方红豆杉叶片上、下表皮细胞近长方形或正方形，均覆盖一层角质层，角质化程度不同，角质层平均厚度分别约为14．78μm和12．53μm。在同一叶片的不同区域，叶表皮细胞形状及大小变化较大，叶中脉处的表皮细胞最大，为152．20μm×37．59μm，长／宽约为4．05；气孔区的表皮细胞形状不规则，细胞大小起伏较大，最大细胞为154．8μm×29．61μm，最小为43．1μm×47．1μm，平均大小为83．89μm×45．31μm，长／宽约为1．85；非气孔分布区的表皮细胞平均大小为99．13μm×40．17μm，长／宽约为2．47。气孔仅分布于下表皮中脉两侧，呈带状，每条气孔带含8—12列气孔，气孔密度为98—159个／mm^2。雌雄植株不同高度叶片的气孔密度均从基部到株顶呈逐渐增加的趋势，但雌雄植株同一高度叶片的气孔密度变化差异不大。在同一高度的叶片中，阳面叶片的气孔密度普遍高于阴面叶片；在同一叶片中气孔密度最高的区域在叶片的中部，向两端逐渐减少，与叶片着生植株的雌雄、方位和高度无关。

元宝山南方红豆杉的群落及种群结构特征

广西是红豆杉的分布区之一，融水县元宝山林区是广西红豆杉分布最集中的区域。元宝山的红豆杉分布在约１０６３ｈｍ２的范围内，资源蕴藏量１１００ｍ３，群落区系组成有４３科６４属 ８０种，种类组成虽不复杂，但几乎为少种属组成，乔木层优势区系成分相当稳定，表明该群落为一个顶极群落。红豆杉种群为稳定种群；种群空间格局为集群分布，从幼苗到大树，其集群程度减小，大树是随机分布。保护红豆杉资源，必须保护其所处的森林群落，且保护重点为红豆杉幼苗。

红豆杉及南方红豆杉体细胞胚胎发生的研究

利用江西的红豆杉（Ｔａｘｕｓｃｈｉｎｅｎｓｉｓ）、福建的南方红豆杉（Ｔａｘｕｓｃｈｉｎｅｎｓｉｓｖａｒ．ｍａｉｒｅｉ）以及四川的南方红豆杉（Ｔａｘｕｓｃｈｉｎｅｎｓｉｓｖａｒｍａｉｒｅｉ）的成熟胚为试验材料，成功地诱导出大量的愈伤组织。这３种材料愈伤组织的最高诱导频率分别为９５７％、９８４％、９１７％。细胞学和形态学的观察结果表明：在适当的条件下经过一段时间的培养，这些愈伤组织能够产生处在不同发育阶段的体细胞胚。上述３种植物材料每１００块愈伤组织平均最多分别可产生１２７、９１和３３个体细胞胚。

南方红豆杉种子中发芽抑制物的研究

对南方红豆杉(Taxus chinensis var.mairei(Lemee et I’ev1.)Cheng et L.K.Fu)种子各部分的甲醇浸提液进行了生物测定,并通过GC-MS联用仪鉴定,以探讨种子中萌发抑制物质与休眠的关系。结果表明:南方红豆杉种子中种皮、内种皮和胚乳的浸提液对白菜种子发芽率和幼苗的高生长、根生长均有抑制作用,且随浸提液浓度的增大,抑制作用逐渐增强。同时,从南方红豆杉种子的胚乳和中种皮、内种皮中鉴定出多种有机化合物,并确定了它们的种类和相对含量,其中包括已报道的正庚酸、壬酸、乙酸等发芽抑制物质。表明南方红豆杉种子的中种皮、内种皮和胚乳中均含有抑制种子萌发和幼苗生长的物质。