大刺儿菜和小刺儿菜的植物化学分类学研究

大刺儿菜和小刺儿菜是形态相似的两个近缘类群,其分类学地位一直存在争论,的有学者把它们归并为一个种。本文通过对其叶的黄酮类化合物层析谱进行比较研究,结果表明两个类群都显示出各自的特征斑点;结合其形态学特征,支持将它们作为两个独立的种。     

蓟属二种植物过氧化物同工酶的酶谱式样及其分类学意义

采用聚丙烯酰胺凝胶电泳的方法对蓟属的两个近缘种：大刺儿菜和小刺儿菜的过氧化物酶同工酶分别在不同的发育阶段和不同的生长下进行了比较研究。结果表明,二者的酶谱存在 明显的差异,从而支持将它们作为两个的种对待。此外,本文还对ＰＯＸ酶谱的分类学意义进行了探讨。     

蓟属两种植物的染色体研究

本文对蓟属（Ｃｉｒｓｉｕｍ）的两个形态相似的近缘种大刺儿菜和小刺儿菜进行了染色体研究,其中后者为首次报道。观察结果表明：两个种的染色体数目均为２ｎ＝２ｘ＝３４：它们的核型是：大刺儿菜．２ｎ＝２ｘ＝３４＝２０ｍ＋１２ｓｍ＋２ｓｔ：小刺儿菜．２ｎ＝２ｘ＝３４＝２２ｍ＋１０ｋｍ（２ＳＡＴ）＋２ｓｔ。通过核型比较,认为它们是两个独立的种．而且后者比前者进化。     

黄土高原苹果园植物多样性及其对昆虫群落的影响

对陕西黄土高原洛川县和黄陵县优质苹果产区不同类型的苹果园植物多样性及其昆虫群落多样性进行调查,确定不同苹果园内果树林下的植物优势种,并利用昆虫多样性指数和均匀度指数分析不同植物优势种群对果园昆虫多样性的影响,以探讨植物群落多样性与其昆虫群落的关系.结果显示:(1)果园野生植物种类丰富,共有24科53属62种,其中17科41属51种存在于果园树下,11种存在于果园内的生境岛屿,且菊科植物种类最多,达14种;(2)抱茎苦荬菜、狗尾草、丝毛飞廉、灰绿藜、刺儿菜、田旋花为该地区果园植物优势种,其重要值依次为0.36、0.22、0.22、0.18、0.17、0.14;(3)反枝苋为优势种的果园昆虫种类、数量最多;(4)刺儿菜和田旋花为优势种的果园益虫和害虫的多样性指数分别为1.073 5、0.755 0和0.879 9、0.360 2.研究表明,在果园保留刺儿菜和田旋花有助于提高果园天敌昆虫群落的多样性,有益于果园害虫的生态控制.     

子午岭地区草本药用植物种间联结性研究

该研究以子午岭地区桥山林区最常见的几种药用植物为研究对象,通过种间联结系数(AC)、Ochai指数(OI)、Jaccard指数(JI),结合Pearson系数和以及χ2统计量对研究区内的药用草本植物两两之间及药用草本植物与本区常见优势木本植物间的种间联结性进行分析,以了解子午岭地区野生药用植物资源的分布。结果显示:(1)药用草本物种间白头翁与苦参、黄精与沙参显示出极显著的正联结关系,而穿龙薯蓣与刺儿菜、翻白草、祁州漏芦、茵陈蒿、远志,刺儿菜与玉竹,翻白草与黄精,黄精与茵陈蒿则表现出极显著的负联结关系。(2)木本植物与药用草本植物的关系因物种不同而异,其中刺槐与刺儿菜、辽东栎与穿龙薯蓣、辽东栎与玉竹、辽东栎与黄精、白桦与穿龙薯蓣均具有极显著的正联结关系;而刺槐与穿龙薯蓣、玉竹,辽东栎与刺儿菜、翻白草、茵陈蒿、苦参,槲栎与龙牙草、茵陈蒿,白桦与天南星、茵陈蒿,油松与益母草,野胡桃与黄精均具有极显著的负联结关系。(3)基于物种关联性的不同,将药用草本植物划分为3个生态种组。研究认为,种间联结性的研究结果可以反映物种的生理生态特性,对该区药用经济植物的资源开发与利用具有一定参考价值。     

观察不同植物耐涝性的一种实验方法

植物在生命过程中离不开水分,但在水分过多或淹水条件下,会对植物产生伤害,不同植物抗涝性不同：通常在讲授涝害时,学生只是从理论上了解．没有感性认识：为使学生能直接观察到植物在淹水条件下的受害特征,增强对理论知识的理解,我们引导学生通过实验观察不同植物的耐涝性,培养学生主动学习的情趣,取得较好的实验效果。     

利用称重法测定植物群落蒸散

用改进的离体连续快速称重法对刺儿菜(Cirsiumsegetum)、苦苣(Sonchusoleraceus)、猪毛蒿(Artemisiascoparia)、长芒草(Stipabungeana)和二裂委陵菜(Potentillabifurca)的蒸腾速率进行了测定,表明二裂委陵菜的蒸腾速率最高、刺儿菜最低,其它处于中间水平。3年退耕地的日蒸腾量远小于裸地的土面蒸发量,群落蒸散量达到0.13～0.64cm·m-2·d-1。     

几种民间止血草药

我国北方先民在耕种劳作中,长期无数次遇到创伤流血的事,总结出多种应急、实效和简便易行的用草药止血救治方法,疗效显著,至今民间仍在应用。现从中筛选几种作一介绍:一、小蓟(Cephalanoplos segetum),别名刺儿菜、刺菜、野红花等。为菊科刺儿菜属多年生草本。混同杂草分布于全国各地,多生长在宅周、路旁、地头或荒地田野中。农田除草,产掉又长,生命力强。地上茎直立,叶长7—10厘米,宽1.5—2.5厘米,椭圆形或椭圆状披针形,互生,边缘有金黄色小刺。头状花序顶生、直立,夏秋季盛开紫红色美丽花朵。瘦果带毛,成熟后自然落地。当小蓟生长季节人…     

黄河三角洲盐碱土壤中AM真菌的初步调查

2000年3月－2001年2月对黄河三角洲盐碱土壤中5种优势植物柽柳（Tamarix chinensis),芦苇（Phragmites communis),碱蓬（Suaeda glauca),獐毛（Aeluropus littralis var.sinensis) 和刺儿菜（Cirsium setosum)根围内丛枝菌根（arbuscular mycorrhiza,AM)真菌进行了长期定点调查,结果表明,AM真菌在这5种植物根围土壤内都有分布,但多样性较低,尤其在冬季,AM真菌种的丰度和孢子密度分别在夏季降低了18．0％和61．6％,不同深度土层中AM真菌的分布存在诸多差异。     

10种菊科植物水提液对小麦幼苗生长的影响

用小白酒草、黄鼠草、刺儿菜、一年蓬、苍耳、苦苣菜、旋覆花、紫菀、黄花蒿、野塘蒿等10种菊科植物的水提液,对小麦进行不同浓度的皿内沙培实验,分别对小麦的根长、苗高及鲜重等三项指标进行测定的统计结果表明：10种菊科植物水提液对小麦幼苗生长的影响依种类有差异,其中旋覆花、黄花蒿、野塘蒿、紫菀对小麦表现出明显克生作用,而小白酒草、黄鼠草则表现出一定的促生作用;刺耳菜、一年蓬、苍耳对小麦幼苗生长的影响不明显。     

四种野菜硝酸盐,亚硝酸盐及维生素C的含量

四种野菜硝酸盐、亚硝酸盐及维生素Ｃ的含量邱贺媛（唐山师范专科学校化学系,唐山０６３０００）Ｔｈｅｃｏｎｔｅｎｔｓｏｆｎｉｔｒａｔｅ,ｎｉｔｒｉｔｅａｎｄｖｉｔａｍｉｎＣｏｆｆｏｕｒｅｄｉｂｌｅｗｉｌｄｖｅｇｅｔａｂｌｅｓＱｉｕＨｅ－Ｙｕａｎ（Ｃｈｅｍ...     

Chemical Composition and Recrystallization of Epicuticular Waxes: Coiled Rodlets and Tubules

Abstract: Coiled rodlets characterize several non-related taxa within the angiosperms. They often occur together with tubules but sometimes also with platelets or transitional forms between them. The ultrastructure chemistry, and recrystallization of epicuticular waxes of three species were investigated by high-resolution scanning electron microscopy, gas chromatography, and mass spectrometry. Whereas Buxus sempervirens (Buxaceae) and Chrysanthemum segetum (Asteraceae) show coiled rodlets in combination with tubules, Leymus arenarius (Poaceae) exhibits tubules but no coiled rodlets. Chemical analyses reveal that the predominating β-diketones of all species differ completely in their molecular structure. Those of the former two species are mainly substituted in carbon atom positions up to 12. In contrast, the wax of L. arenarius contains only hentriacontane-14,16-dione and 25-hydroxy-hentriacontane-14,16-dione. Standard solutions of the total waxes from B. sempervirens, C. segetum and L. arenarius, the purified β-diketone fraction from C. segetum and hentriacontane-14,16-dione from Secale cereale were taken for recrystallization experiments under different conditions in relation to solvent and crystallization velocity. It was demonstrated that coiled rodlets grew exclusively from total waxes of B. sempervirens and C. segetum, and its β-diketone fraction but never from L. arenarius wax or pure hentriacontane-14,16-dione. The recrystallization experiments pointed out that conditions, such as the chemical environment and physical factors, strongly influence the formation of coiled rodlets and tubules. It is concluded that coiled rodlets are formed by self-assembly in close dependence on the position of β-diketo substitution. The future role of β-diketones in the classification of coiled rodlets within wax crystals is discussed.     

An NADPH and FAD dependent enzyme catalyzes hydroxylation of flavonoids in position 8

Yellow flavonols contribute to flower pigmentation in Asteraceae. In contrast to common flavonols, they show additional hydroxyl groups in position 6 and/or 8 of the aromatic A-ring in addition to the basic 5,7-hydroxylation pattern. An enzyme introducing a hydroxyl group in position 8 of flavonols and flavones was demonstrated for the first time with enzyme preparations from petals of Chrysanthemum segetum. Flavanones, dihydroflavonols and glucosylated flavonols and flavones were not accepted as substrates. The enzyme was localized in the microsomal fraction and uses NADPH and FAD as cofactors. Experiments with carbon monoxide/blue light and with antibodies specific for cytochrome P450 reductase did not indicate the involvement of a classical cytochrome P450 dependent monooxygenase in the reaction. Thus, the flavonoid 8-hydroxylase represents a novel type of hydroxylating enzyme in the flavonoid pathway. Apart from flavonoid 8-hydroxylase activity, the presence of all enzymes involved in the formation of flavonoid 7-O-glucosides in C. segetum was demonstrated. The pathway leading to 8-hydroxyflavonoids in C. segetum has been derived from enzyme activities and substrate specificities observed.     

A species-specific sperm-activating peptide from the egg jelly of the sea urchin Diadema setosum

1. A species-specific sperm-activating peptide was isolated from the egg jelly of the sea urchin Diadema setosum and the amino acid sequence was determined as follows: (formula; see text). 2. The peptide caused significant increases of respiration rates and cyclic nucleotide concentrations in D. setosum spermatozoa as low as 10(-9) M. 3. The addition of the peptide to D. setosum spermatozoa resulted in the appearance of a newly stained protein (mol. wt 128,000) on sodium dodecyl sulfate-polyacrylamide gels.     

黄地老虎幼虫取食诱导的棉花植株挥发物驱避雌蛾产卵

[目的]评价黄地老虎Agrotis segetum幼虫取食危害诱导棉花植株产生的虫害诱导植物挥发物(herbivore-induced plant volatiles,HIPVs)对雌蛾产卵选择的影响,并鉴定HIPVs的主要组分及其功能,以筛选对雌蛾产卵有吸引或驱避作用的活性成分.[方法]利用气相色谱-质谱联用仪(GC...     

Comparative study on the susceptibility of cutworms (Lepidoptera: Noctuidae) to Agrotis segetum nucleopolyhedrovirus and Agrotis ipsilon nucleopolyhedrovirus

The common cutworm (Agrotis segetum) and the black cutworm (Agrotis ipsilon) are serious soil pests of many vegetable and field crops all over the world. We have demonstrated the cross-infectivity of two baculoviruses, A. segetum nucleopolyhedrovirus (AgseNPV) and A. ipsilon nucleopolyhedrovirus (AgipNPV) for these two insect pests. The susceptibility of A. segetum to AgipNPV was confirmed by DNA restriction endonuclease analyses of DNA isolated from virus harvested from infected A. segetum larvae. For an initial comparison of both viruses, partial polyhedrin sequences were amplified by PCR, cloned, and sequenced. Both viruses shared a very similar polyhedrin gene sequence resulting in only three amino acid substitutions. Phylogenetic analyses clearly demonstrated that both viruses belong to NPV group II and are most closely related to a clade consisting of Spodoptera exigua NPV, Spodoptera frugiperda NPV, and Spodoptera littoralis NPV. Since AgipNPV shows high virulence for both cutworm species, it appears to be a suitable candidate as a single biological control agent of A. segetum and A. ipsilon.     

Differentiation of Cirsium japonicum and C. setosum by TLC and HPLC-MS

The Chinese Pharmacopoeia indicates the use of field thistle (Cirsium setosum) and Japanese field thistle (C. japonicum) in the treatment of bleeding and inflammation. In the absence of an analytical method for the differentiation and analysis of these two species, TLC and HPLC-MS methods have been developed for this purpose. Both species could be readily distinguished by their flavonoid pattern as revealed by TLC on silica gel layers eluted with ethyl acetate:formic acid:acetic acid:water. The quantitative determination of four flavonoids, namely hispidulin-7-neohesperidoside, linarin, pectolinarin and luteolin, was possible using HPLC. Their optimum separation was achieved on a C12 column eluted with water and 0.025% trifluoroacetic acid in acetonitrile. HPLC-MS experiments were performed to confirm peak identity. In samples of C. japonicum, pectolinarin was the major flavonoid (0.32-2.00%), followed by linarin, hispidulin-7-neohesperidoside and luteolin; the total flavonoid content varied from 0.81 to 3.67%. In C. setosum only one flavonoid (linarin; 1.36-2.83%) was assignable. The HPLC method was validated for linearity, limit of detection (< or = 1.7 ng on-column), peak purity, repeatability (< or = 2.3%) and accuracy (recovery rates of spiked samples were between 99.2 and 101.6%).     

The taxonomy and biology of Stenosiphonium Nees (Acanthaceae)

A taxonomic revision of Stenosiphonium Nees is provided. Morphological variation within the genus is documented, the relationship between Stenosiphonium and Strobilanthes Blume is discussed, and problems of species delimitation are resolved. Three species are recognized. Stenosiphonium cordifolium (Vahl) Alston is morphologically variable and is widespread throughout peninsular India and Sri Lanka. S. setosum T. Anderson and S. wightii Bremek. are restricted endemics from the southern Western Ghats, each known from very few herbarium collections. Both S. setosum and S.wightii are recognized as rare in accordance with IUCN criteria. There is evidence to suggest that all three species of Stenosiphonium are plietesial which may explain the paucity of herbarium collections of both S. setosum and S. wightii. The implications of a plietesial lie history strategy for the assessment of the conservation status of these species is considered.