珍稀水生植物——宽叶泽苔草的核型研究

宽叶泽苔草（Caldesia granis Samuel）。是一种珍稀濒危水生植物。它曾经一度被认为已经从中国大陆灭绝,但最近又在湖南省的一个高山沼泽中被发现。本文首次报道了依据上述新发现地点的宽叶泽苔草材料进行的细胞学研究结果。核型分析结果表明：本种染色体数目为22,其染色体组型高度不对称。结合前人对宽叶泽苔草一些近缘种的细胞学及古生物学研究结果,作者认为泽苔草属植物很可能是泽泻科中最进化的一个属。     

宽叶泽苔草的花器官发生

通过扫描电镜观察了宽叶泽苔草Caldesia grandisSamuel.的花器官发生。宽叶泽苔草 的萼片3枚,逆时针螺旋向心发生 ;花瓣3枚,呈一轮近同时发生,未观察到花瓣_雄蕊复合原基;雄蕊、心皮原基皆轮状向心 发生,最先近同时发生的6枚原基全部发育成雄蕊,随后发生的6枚原基早期并无差别,在发 育过程中逐渐出现形态差异,直至其中1－4枚发育成心皮,其余的发育成雄蕊;而后的几轮 心皮原基,6枚一轮,陆续向心相间发生。本文揭示了3枚萼片螺旋状的发生方式,并推测这种螺旋方式是泽泻科植物进化过程中保留下来     

苔草属果实表皮的超微结构及其在分类学上的意义

报道了国产苔草属,两亚属,７组中的１６种植物在电子显微镜下果实表皮的特征和研究结果。根据种内个体间、组内种间以及亚属间的比较,作者认为在苔草属中,果实表皮显微特征在种内个体间比较稳定,变异很上;同组内种间表现出的较大相似性和不同组间存在的一定差异性。说明在组和组下等级的分类学处理以及在系统位置和亲缘关系的探讨上,果实显微特征具有重要的分类学价值。同时由于是微特征在各间甚至属间相互交叉和渗透,在划分     

木兰属萜类生源途径及其分类学意义

选取木兰科木兰属15种植物的108种萜类化合物成分作为研究资料,根据各种萜类化合物成分的结构类型从中找出34条可能的生源合成途径,并将各种生源途径作为数量性状,用聚类分析的方法得到木兰属各分类群之间的相关系数、作出树形分支图,根据所含萜类比较复杂成分的比例对该属的演化关系作出推论,结果表明木兰亚属与玉兰亚属是属于平行演化的两支。     

八角属萜类成分及其化学分类意义

以八角属植物中所含的萜类成分为基础,把各种萜类成分按照其所属的基本骨架类型进行整理,将各种骨架类型萜类的总含量作为数量性状,采用SPSS系统进行聚类分析研究,作出八角属的树形分支图。结合八角属的形态特征和地理分布探讨八角属的化学分类意义。     

中国蒺藜植物黄酮类化学成分分析及其化学分类学意义

采用薄层层析和高效毛细管电泳（ＨＰＣＥ）等方法,对中国蒺藜科５属的代表性植物中的黄酮类成分进行了分析研究,并结合其它分类学性状进行了初步讨论,我们同意：（１）支持Ｅｎｇｌｅｒ（１９３１）骆驼蓬亚科（Ｐｅｇａｎｏｉｄｅａｅ）地位;（２）支持Ｔａｋｈｔａｊａｎ（１９８７）白刺科（Ｎｉｔｒａｒｉａｃｅａｅ）的恢复;（３）支持ＥＩ－Ｈａｄｉｄｉｄ（１９９７）刺蔟藜科（Ｔｒｉｂｕｌａｃｅａｅ）的建立。     

中国蒺藜科植物黄酮类化学成分分析 及其化学分类学意义

采用薄层层析和高效毛细管电泳(HPCE)等方法,对中国蒺藜科5属的代表性植物中的黄酮类成分进行了分析研究,并结合其它分类学性状进行了初步讨论,我们同意(1)支持Engler(1931)骆驼蓬亚科(Peganoideae)地位;(2)支持Takhtajan(1987)白刺科(Nitrariaceae)的恢复;(3)支持EI-Hadidi(1977)刺蒺藜科(Tribulaceae)的建立。     

卫矛属刺果卫矛组的数量分类学分析

通过对1500余份标本的测量和统计,结合文献和野外考察,选取了30个形态学性状,对卫矛属（Euonymus）刺果卫矛组（sect. Echinococcus）13个种进行了数量分类学分析。聚类分析结果表明,美国卫矛（E.americanus）和陈谋卫矛（E.chenmoui）的亲缘关系最近,不支持Blakelock将本组划分为两个系的观点。本组中系统位置有争议的物种：厚叶卫矛（E.hemsleyanus）与紫刺卫矛（E.angustatus）、棘刺卫矛（E.echinatus）和无柄卫矛（E.subsessilis）、刺猬卫矛（E.hystrix）和蒙自卫矛（E.mengtseanus）、刺果卫矛（E.acanthocarpus）和腾冲卫矛（E.tengyuehensis）,在聚类图中显示出较远的亲缘关系,通过方差分析对这些物种间有较明显差异的性状进行进一步分析。结果表明,这些物种在叶尖角度、叶长、侧脉与主脉的夹角、花序梗长等性状上均具有显著差异。分析结果支持将蒙自卫矛与腾冲卫矛排除出刺果卫矛组,支持厚叶卫矛和紫刺卫矛作为独立的种,由于在交叉分布地域没有足够的研究资料,棘刺卫矛和无柄卫矛的系统位置有待进一步确认。因子分析结果表明,本实验所用性状间的独立性较强,叶长、侧脉与主脉的夹角、花序分支数、果实带刺的长度等18个性状在本组中具有重要的分类学意义。     

滇芎属与瘤果芹属果实表面微形态特征及其分类学意义

对中国伞形科滇芎属(Physosperm opsisW olff)和瘤果芹属(TrachydiumL ind l.)12个种的果实表面微形态特征进行了扫描电镜比较观察。根据果实棱槽、外果皮细胞轮廓和蜡条纹饰的特征,这2个属的果实表面微形态可划分为3种类型:1)棱槽平滑-外果皮细胞轮廓不可见-无或少蜡质纹饰型;2)棱槽具瘤-外果皮细胞轮廓不可见-蜡质纹饰近平直或线纹型;3)棱槽粗糙-外果皮细胞呈4~6边形-蜡质纹饰波纹或网纹型。在此基础上,结合形态学特征探讨了滇芎属与瘤果芹属之间的关系和属下种间关系。     

链格孢菌酯酶同工酶分析及其分类学意义

分析了20株链格孢菌的酯酶同工酶聚丙烯酰胺凝胶电泳图谱,并将酶谱进行聚类分析。结果发现:20株链格孢菌在37%的相似系数处明显分为大孢子组和小孢子组;大孢子组在52%的相似系数处分为6组,每组代表1个种,小孢子组在较高的相似性水平上分组与形态分组结果基本一致。本试验结果还表明:酯酶同工酶电泳方法简单易行,能准确反映种间的微小差异,适用于链格孢属真菌的种级分类,可作为传统形态学分类的一个重要辅助手段。     

Chemical analysis of diterpenoids in Caldesia grandis and its chemotaxonomic implication

Caldesia grandis is a rare and endangered aquatic plant of the Alismataceae family. This paper first reports 43 chemical components of C. grandis based on the gas chromatography-mass spectrometry and reviews research on the chemical compositions of some closely related genera such as Alisma, Sagittaria, and Echinodorus. Their common chemical components are diterpenoids. Kaurane diterpenoids are found in Caldesia, Alisma and Sagittaria; clerodane diterpenoids in Sagittaria and Echinodorus; and pimarene and abietene diterpenoids in Sagittaria. By the biogenesis of diterpenoids, kaurane and abietene diterpenoids represent evolutionarily derived compounds, clerodane diterpenoids are primordial, and pimarene diterpenoids are intermediate. The chemotaxonomy, karyotypical analysis and fossil records of those genera showed that Caldesia was evolutionarily closer to Alisma than to Sagittaria and Echinodorus. Possible evolution levels of Echinodorus, Sagittaria, Alisma, Caldesia in chronological order are derived.     

宽叶泽苔草居群内遗传多样性研究

(武汉大学生命科学学院植物系统学与进化生物学研究室,武汉430072)摘要:采用RAPD分子标记对宽叶泽苔草(Caldesiagrandis)湖南浪畔湖居群30个家系共180个子代样品进行了居群内家系间以及家系内的遗传多样性分析。从100个随机引物中筛选出12个有效引物,共产生112条带,其中79条表现出多态性,占总条带数的70.5%。宽叶泽苔草各个家系多态位点百分率(PPB)在7.1%–40.2%之间。各个家系基因多样性范围在0.02–0.14之间(家系水平的基因多样性为0.10),Shannon指数的范围在0.04–0.21之间(家系水平的Shannon指数为0.18)。对宽叶泽苔草30个家系的AMOVA分析结果显示,家系间的基因分化系数Gst=0.231,即总的变异中有23.1%的变异存在于家系间,家系内的遗传变异占总遗传变异的76.9%,家系间和家系内变异均极显著(P<0.001)。采用UPGMA法对宽叶泽苔草30个家系180个子代进行聚类的结果表明:同一家系的子代个体并不能完全聚在一起。基于家系间的遗传分化系数Gst对宽叶泽苔草30个家系间的基因流进行估测,结果显示:Nm=0.83,表明宽叶泽苔草各个家系之间有较高的基因流。     

琯溪蜜柚和度尾蜜柚自交和互交胚珠发育状况的比较

用石蜡切片技术对溪蜜柚 (Citrus grandis cv.Guanxim iyou)和度尾蜜柚 (C.grandis cv.Duweimiyou)自交和互交胚珠发育进行了比较观察。溪蜜柚的自交授粉后胚珠发育有 2种不同情形 (I型和 II型 ) , 型在授粉后5 d的珠心组织细胞有变形现象 ,接着胚囊萎缩 ,但外珠被能生长发育到 5 0 d左右 ; 型受精后胚乳发育异常 ,种子不能发育。度尾蜜柚自交胚囊中胚乳没有出现 ,在授粉后 35 d左右珠心组织和囊腔同时萎缩。互交胚珠发育正常 ,成熟果实有籽。表明两品种是自交不亲和的 ,导致了果实无籽。但两者的识别反应和阻抑部位不同 ,溪蜜柚 I型可能出现在受精前 , 型出现在受精后 ,而度尾蜜柚自交花粉管可能没有进入胚囊 ,是一种受精前的障碍。瘪籽的大小与不亲和障碍发生的时期有关。实验为进一步研究两品种的自交不亲和性遗传机理提供了实验证据 ,将有助于解决由于果实无籽导致的汁胞粒化、裂果、裂瓣等品质问题。     

RAPD diversity of Stipa grandis populations and its relationship with some ecological factors

The genetic diversity of Stipa grandis P.Smirn and its relationship with the climatic variables were studied using the RAPD technique for 90 genes from five natural populations sampled in the Xilingol steppe, China. Sixteen oligonucleotides screened from 100 random primers were used to amplify 310 trackable RAPD loci, which were all polymorphic. By analyzing the RAPD data using POPGENE software, different geographic S. grandis populations were studied, which indicated a high level of genetic diversity, and the maximum variation was observed within the populations with a 28% variation observed among the populations. Using Pearson correlation analysis, significant (P < 0.05) or highly significant (P < 0.01) relationships were found between gene diversity indexes and temperature factors (≥10C cumulative temperature in a year, annual mean temperature and mean temperature in January). Mantel's tests showed that there was no significant correlation between Nei's unbiased genetic distance and the geographic distance of S. grandis populations (r = 0.184, P = 0.261). However, there were significant or highly significant correlations between Nei's genetic distance and the several climatic divergences in pairwise S. grandis populations. All results indicated that natural selection resulting from variations in water and temperature was responsible for the adaptive eco-geographical differentiation indicated by the RAPD markers of different S. grandis populations, and that immigration and gene drift did not play an important role in affecting the differentiation of S. grandis populations.     

RAPD diversity of Stipa grandis populations and its relationship with some ecological factors

The genetic diversity of Stipa grandis P.Smirn and its relationship with the climatic variables were studied using the RAPD technique for 90 genes from five natural populations sampled in the Xilingol steppe, China. Sixteen oligonucleotides screened from 100 random primers were used to amplify 310 trackable RAPD loci, which were all polymorphic. By analyzing the RAPD data using POPGENE software, different geographic S. grandis populations were studied, which indicated a high level of genetic diversity, and the maximum variation was observed within the populations with a 28% variation observed among the populations. Using Pearson correlation analysis, significant (P < 0.05) or highly significant (P < 0.01) relationships were found between gene diversity indexes and temperature factors (≥10°C cumulative temperature in a year, annual mean temperature and mean temperature in January). Mantel's tests showed that there was no significant correlation between Nei's unbiased genetic distance and the geographic distance of S. grandis populations (r = 0.184, P = 0.261). However, there were significant or highly significant correlations between Nei's genetic distance and the several climatic divergences in pairwise S. grandis populations. All results indicated that natural selection resulting from variations in water and temperature was responsible for the adaptive eco-geographical differentiation indicated by the RAPD markers of different S. grandis populations, and that immigration and gene drift did not play an important role in affecting the differentiation of S. grandis populations.     

巨桉家系主要产量性状遗传相关分析

遗传相关分析表明,巨桉家系各性状间相关极显著,胸径与材积的遗传相关比树高与材积之间的遗传相关更密切。遗传相关系数大于表型相关系数,以遗传相关系数进行间接选择较科学。通径分析进一步揭示,胸径是构成巨桉单株材积的最主要因素。     

Chemical constituents from Psychotria yunnanensis and its chemotaxonomic study

Phytochemical investigation on the aerial parts of Psychotria yunnanensis led to the isolation of four norisoprenoids (1–4), one monoterpenoid (5), and eleven phenolic compounds (6–16). To our knowledge, all compounds were isolated from this plant for the first time. Compounds 2–16 were reported for the first time from the genus Psychotria. The chemotaxonomic significances of these compounds were summarized.     

巨桉人工林中小型土壤动物类群分布规律

研究了四川省洪雅县巨桉人工林中小型土壤动物类群及数量分布规律.结果表明,巨桉人工林四季共获中小型土壤动物13 550头,分属6门13纲26目,以蜱螨目、线虫纲、弹尾目为优势类群,以线蚓科为常见类群.各样地中小型土壤动物类群数、个体数均有明显季节变化,以秋季或冬季最高,春季最低,夏季次之.中小型土壤动物密度剖面分布表聚性明显,但在5～10 cm和10～15 cm土层间有时会出现逆向分布现象.中小型湿生土壤动物密度为3.333×10³～2.533×10⁵个·m^-2,中小型干生土壤动物密度为1.670×10²～2.393×10⁵个·m^-2,中小型湿生土壤动物密度自上而下减少的速率小于中小型干生土壤动物.巨桉人工林中小型土壤动物密度-类群(DG)指数以春季最低,秋季或夏季最高（可达6.637）.巨桉人工林与青冈次生林中小型土壤动物密度及DG指数均无显著差异.