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1.
蔷薇亚科4属4种植物幼苗形态结构及其系统演化分析   总被引:2,自引:0,他引:2  
郭洁  汪矛  王丽  梁彦  周树敏 《西北植物学报》2006,26(8):1562-1568
通过对蔷薇亚科蛇莓属的蛇莓[Duchesnea indica(Andrews)Focke]、委陵菜属的翻白草(Potentilla dis-colorBunge)、水杨梅属的水杨梅(Geum aleppicumJacq.)和地榆属的地榆(Sanguisorba officinalisL.)4种植物幼苗形态特征以及初生维管系统的结构研究表明:蛇莓、翻白草子叶脉序中主脉与两侧二级脉呈原始的二叉分支状,蛇莓脉序中无二级间脉,翻白草中为简单型的二级间脉;水杨梅、地榆的主脉与两侧二级脉呈进化的对生分支状,二者的二级间脉为复合型.蛇莓属幼苗子叶节区下部的中柱为原始的中始式二原型圆形单中柱,委陵菜属为较进化的外始式二原型圆形单中柱,水杨梅属为外始式二原型双钩型的单中柱,而地榆属的外始式二原型双扇型的单中柱则最为进化,并且地榆的后生木质部发达,也是进化的表现.综合叶脉数量和级数以及子叶节区下部的中柱类型分析,认为4属的演化趋势为:蛇莓属最原始,其次为委陵菜属和水杨梅属,地榆属最为进化.  相似文献   

2.
莎草科4种植物种子休眠与萌发特性的研究   总被引:2,自引:0,他引:2  
以嵩草、黑穗苔草、藨草和苔草4种莎草科植物种子为材料,研究了硫酸、植物生长调节剂及低温层积处理对其休眠与萌发特性的影响,以揭示其休眠机制及其破除方法,为指导生产提供理论依据。结果表明:(1)4种参试植物种子均存在不同程度的生理休眠,其中嵩草为浅度生理休眠,黑穗苔草为中度生理休眠,藨草和苔草为深度生理休眠。(2)浓硫酸浸种可显著提高嵩草、黑穗苔草种子的萌发,随浸种时间增加,种子萌发率先增加后降低,最大值分别达86%、77%,但浓硫酸处理对藨草和苔草的种子萌发无显著促进作用。(3)赤霉素(GA3)、氟啶酮(FL,脱落酸抑制剂)和KNO3单独处理可显著提高嵩草种子萌发,但对其他3种植物种子无显著作用;而硫酸处理后再用赤霉素或氟啶酮处理,则显著促进黑穗苔草种子的萌发率。(4)低温层积对种子萌发的影响因种与层积时间而异,层积2个月可显著提高嵩草种子萌发,层积4个月可显著提高嵩草和藨草种子萌发;层积6个月可显著提高嵩草、黑穗苔草、藨草和苔草4种植物种子萌发,其最终萌发率分别为90%、73%、17%、7%。  相似文献   

3.
4种野生牡丹种子休眠和萌发特性及与其致濒的关系(英文)   总被引:1,自引:0,他引:1  
与栽培牡丹相比,野生矮牡丹、四川牡丹和紫斑牡丹的种子一般较小,但野生黄牡丹种子则明显大于栽培牡丹。这4 种濒危的野生牡丹种子的休眠与萌发特性与栽培牡丹的有明显差异:萌发生根期需半年以上,但通过胚培养可使之减至2 周;萌发温度以10~15℃为宜, 超过20℃则明显不利于生根及上胚轴生长; 打破上胚轴休眠需要严格的低温;野生牡丹种子的萌发率及打破上胚轴休眠后的出苗率也大大低于栽培牡丹,而且在不同分布地之间存在较大差异。实验证明:在自然状态下野生牡丹缺乏充分的传粉,特别是居群间的传粉不足,导致其种子质量低下;而野生牡丹种子特殊的萌发特性,特别是严格的上胚轴休眠,则是导致其出苗率极低及自然状态下幼苗和种群稀少的重要内因。生化测定结果表明:在低温打破牡丹种子上胚轴休眠过程中,子叶中的萌发促进剂GA3 含量明显升高,抑制剂ABA 含量显著下降;而胚乳中的各种激素含量则变化不大,胚轴中的激素变化无明显规律,因此认为子叶是控制牡丹种子上胚轴休眠的关键部位。  相似文献   

4.
四种湿地植物在人工湿地的生长特性研究   总被引:1,自引:0,他引:1  
研究了表面流人工湿地中香根草(Vetiveria zizanioides)、风车草(Cyperus flabelliformis)、芦苇(Phrogmites australis)和水鬼蕉(Hymenocallis littoralis)4种植物的根生物量和生长量、根系分布、地上部分的生长情况.风车草、香根草和水鬼蕉根系及地上部分的生长节律相似,9月或10月前生长较快,以后生长减慢甚至停止;芦苇则不同,7月以前生长缓慢,以后生长加速,冬季也保持较快的生长.全年根生长量和根生物量以水鬼蕉最大,显著高于其它植物(P<0.01),香根草最小,显著低于其它3种植物(P<0.01).香根草的根系垂直向下生长,分布较深,而其它3种植物的根系主要分布在浅层土壤中.风车草分株最多,叶面积指数最大.香根草叶面积指数最小.结果表明,在构建多种植物人工湿地群落时,可以考虑将芦苇与大多数湿地植物搭配以保证湿地全年保持较好的净化效果;水鬼蕉可以作为底层植物,和风车草等生长早、植株较高的植物构建多种湿地群落.  相似文献   

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在雀形目鸟类系统分类和进化研究中,鸣声有重要作用。褐鹛属(Fulvetta)是近年从雀鹛类(Alcippe)独立的属,其鸣声特征及种间差异尚缺乏定量研究。我们于2016至2022年在野外录制了该属7种463只个体的鸣声,包括棕头雀鹛(F. ruficapilla,n=64)、褐头雀鹛(F. manipurensis,n=71)、白眉雀鹛(F. vinipectus,n=124)、中华雀鹛(F. striaticollis,n=64)、路氏雀鹛(F. ludlowi,n=33)、灰头雀鹛(F. cinereiceps,n=84)和玉山雀鹛(F. formosana,n=23)。基于野外行为观察,将鸣声区分为鸣叫和鸣唱,并将鸣叫分为联络鸣叫、呼唤鸣叫、报警鸣叫及觅食鸣叫4种类型。对鸣唱的声谱图进行人工检视,划分为1~8种鸣唱型。采用多变量方差分析(MANOVA)比较鸣声参数种间差异,显示最高频率、最低频率、峰频率、句子持续时间、频率宽度、平均熵6个参数在该属7种间均有显著性差异。将7种褐鹛鸣声特征的马氏距离与种间遗传距离进行Mantel检验,表明鸣唱特征与种间遗传距离呈正相关(r=0.51...  相似文献   

7.
四种重楼属植物光合作用特征   总被引:1,自引:0,他引:1  
Species of Paris (Trilliaceae) have often been used as medicinal plants. Because of excessive exploitation,in this regard the wild resource of Paris is almost exhausted. Some species of Paris were transplanted for use in photosynthesis research and for conservation purposes. In the present study, light and CO2 photosynthetic response curves were investigated in four Paris taxa: P.polyphylla var. yunnanensis and var. alba, P.mairei, and P.marmorata. Our results showed that P.marmorata had the highest maximum photosynthetic rate (Pmax; 8.6μmol·m-2·s-1), light saturation point (LSP; 827μmol·m-2·s-1), maximum electron transport rate (Jmax; 39.9mol·m-2·s-1), a relatively high maximum carboxylation rate (Vcmax; 28.9μmol·m-2·s-1) and carbon dioxide saturation point (Cisat; 726μmol·mol-1), but a lower light compensation point (LCP; 6.23μmol·m-2·s-1) and the lowest carbon dioxide compensation point (Г*; 20.7μmol·mol-1). This suggests that P.marmorata is well adapted to light and CO2; however it has a low ability to acclimate to environmental stress as indicated by low water use efficiency (WUE) in high light conditions. P.polyphylla var. yunnanensis had the highest light compensation point (LCP; 10.1μmol·m-2·s-1), carbon dioxide compensation point (Г*; 35.3μmol·mol-1), carbon dioxide saturation point (Cisat; 727μmol·mol-1), relatively high maximum photosynthetic rate (Pmax; 7.5μmol·m-2·s-1) and light saturation point (LSP; 728μmol·m-2·s-1), maximum light saturated electron transfer rate (Jmax; 37.7μmol·m-2·s-1), suggesting that it is suitable for conditions of higher light and CO2 concentration. This taxon can adapt to adverse conditions, as suggested by high WUE under increased CO2 concentration. In contrast, P.polyphylla var. alba exhibited a relatively lower apparent quantum yield (AQY; 0.037μmol·mol-1) and poorer growth performance than the other taxa. We suggest from our results that different light and water conditions are suitable for the growth of the different taxa. Photosynthesis assimilation efficiency and production can be increased by raising humidity for P.polyphylla var. yunnanensis and P.marmorata. To protect plants of P.polyphylla var. alba from strong sunshine, they should be shaded from March to mid June.  相似文献   

8.
四种红曲菌各自固有的分子生物学和生物化学特性   总被引:1,自引:0,他引:1  
对白色红曲菌、火红色红曲菌、烟灰色红曲菌和橙色红曲菌各自固有的核糖体内转录间隔区(ITS)rDNA序列和生物化学特性进行了研究。rDNA ITS测序结果显示,橙色红曲菌与火红色红曲菌相同,而白色红曲菌与灰色红曲菌相同,这两组经序列比对仅有2个碱基不同。从生物化学特性来看,作为分类指标,似乎有物种属(genus)的共性也有个体(株)质的差异或量的差异。  相似文献   

9.
四种植物内生真菌的分离及其抗肿瘤活性的筛选   总被引:2,自引:0,他引:2  
从银杏、合欢、臭椿和苦楝的树皮中分离到61株内生真菌。MTT法检测显示在45.9%的菌株发酵液粗提物在200 μg/mL时对人食道癌细胞EC109的生长抑制率大于50%。其中6株内生真菌(YX5, YX17, YX36, KL1, CC1, CC5)在50 μg/mL时仍具有较高的细胞毒活性, 且活性成分主要分布在菌株的发酵液中。合欢内生真菌中的活性菌株比例最小, 在50 μg/mL时均未显示任何对EC109细胞的抑制作用。银杏中的高活性菌株比例最大, 占银杏内生真菌的15.8%。银杏分离菌株YX5的活性最为突出, 其发酵液粗提物对3种肿瘤细胞EC109, HONE1和HeLa的抑制率IC50分别是18.3 μg/mL、3.6 μg/mL和6.5 μg/mL。研究结果表明, 作为抗肿瘤药物的潜在来源银杏内生真菌值得关注。  相似文献   

10.
Antigenic analyses of Lactobacillus bulgaricus, Lactobacillus lactis, Lactobacillus brevis and Lactobacillus buchneri were carried out by double immunodiffusion in agar. Antigens were extracted from whole cells and cell wall preparations with cold trichloroacetic acid. Most strains of the four species possessed antigen 9 in their cell walls. Another antigen, antigen 10, was found in the cell walls of all the strains of L. brevis and L. buchneri, and in some strains of L. lactis, but not in L. bulgaricus. Fractionation of the antigens was attempted using the cell wall extracts of L. lactis L-10 with only antigen 9 and of L. brevis X-1 with both antigens 9 and 10. The partially purified fractions of antigen 9 and of the complex of antigens 9 and 10 were obtained by zone electrophoresis. However, antigen 10 from the complex could not be separated by the same method or gel filtration on Sephadex G-100 since the two antigens 9 and 10 of the complex always behaved together. The fraction of antigen 9 consisted almost entirely of glycerol and glucose as sugar components, the molar ratio being 2: 1. The complex of antigens 9 and 10 also consisted of the same sugars, and the molar ratio of glycerol: glucose was 4: 1. Inhibition tests indicated that the immunodominant component of antigen 9 was a-methylglucoside (glucose), and most probably the determinant is a glycosylated glycerol teichoic acid. It was considered that the determinant of antigen 10 is a glycerol teichoic acid although glucosamine and galactosamine inhibited effectively the reaction between antigen 10 and its antibody.  相似文献   

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Lactose-Hydrolyzing Enzymes of Lactobacillus Species   总被引:9,自引:5,他引:4       下载免费PDF全文
beta-Galactosidase (beta-gal, EC 3.2.1.23) and beta-D-phosphogalactoside galactohydrolase (beta-Pgal) activities were observed in all of 13 Lactobacillus species studied except L. casei and L. buchneri. Only the latter enzyme was detected in nine strains of L. casei. The beta-gal from L. thermophilus and the beta-Pgal from L. casei were purified and characterized. In comparison with beta-gal, the beta-Pal was slightly less active (V(max) values were 28.9 and 50.0 mumoles per mg per min, respectively), but the substrate affinitives were similar (K(m) values were 1.69 x 10(-3) M and 1.59 x 10(-3) M, respectively). Although the two enzymes had similar amino acid compositions, the molecular weight of beta-gal was 5.4 x 10(5) and that of beta-Pgal was 1.3 x 10(5). The beta-gal from L. thermophilus and the beta-Pgal from L. casei had optimal temperature and pH activity values of 55 C at pH 6.2 and 37 C at pH 5.0, respectively. The complete absence of beta-gal from a homofermentative Lactobacillus species of industrial importance is further evidence of the heterogeneity of this genus.  相似文献   

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4种桫椤初生叶的形态发育及其系统学意义   总被引:2,自引:0,他引:2  
用腐叶土培养海南白桫椤(Sphaeropteris hainanensis)、阴生桫椤(Alsophila latebrosa)、刺桫椤(A.spinulosa)和滇南桫椤(A.austroyunnanensis)的孢子,获得有性生殖苗.观察并比较了幼孢子体最初4枚叶片形态发生的详细过程,据此讨论了其种属划分的合理性及相关的系统学意义.  相似文献   

15.
利用扫描电镜对现生非洲鸵鸟Struthio camelus、美洲鸵Rhea americana、鸸鹋Dromaius novaehollandiae和鹤鸵Casuarius casuarius蛋壳进行了对比.描述了4种蛋壳内外表面及径切面的形态特征和层次.结果 显示鸸鹋与鹤鸵蛋壳外表面粗糙,具有明显的网状层;而非洲鸵和美洲鸵蛋壳更加近似.因而推测它们分别在形态发生和进化上存在某些联系,这与现代分子进化的研究结果一致.  相似文献   

16.
Rod-shaped structures have been observed in cells of Pseudomonas, Photobacterium, Proteus, and Saprospira by use of the negative-contrast stain. These structures, referred to as rhapidosomes, appear to be normal components of these cells. Other bacteria including Escherichia, Salmonella, Shigella, Klebsiella, Micrococcus, Bacillus, Mycobacterium, Rhodospirillum, and Hydrogenomonas genera failed to reveal these structures. The rhapidosomes of Saprospira were found to consist of two rods, one encasing a narrower, longer structure. In contrast, the rhapidosomes of Pseudomonas, Proteus, and Photobacterium were without the rigid inner structure, but were occasionally seen filled with a homogeneous material as observed by the negative stain. Ultrathin sections of Pseudomonas cells indicate that these rhapidosomes are embedded within or are in close association with the nucleoplasm.  相似文献   

17.
郭浩  庄伟伟  李进 《西北植物学报》2019,39(12):2263-2270
为了深入了解古尔班通古特沙漠植物在极端环境下养分循环及限制状况,以琉苞菊(Hyalea pulchella)、假狼紫草(Nonea caspica)、尖喙牻牛儿苗(Erodium oxyrrhynchum)和飘带果(Lactuca undulata)为研究对象,分析了4种短命植物的生物量与化学计量特征变化以及二者之间的相关性。结果表明,(1)4种荒漠植物生物量分配在整个生长周期内呈一致增长规律,而根冠比(R/S)均呈下降趋势;生物量累计速率在各生长期不尽相同,但4种植物随生活史的完成最终分配比例趋同。(2)4种植物的C元素在整个生长周期内居高不下,N、P元素在植物体内总体呈下降趋势。对计量比分析发现,C∶N与C∶P间呈正相关关系,且二者都与N∶P呈负相关关系,但N∶P则相比旱生植物的平均值低。(3)生物量与化学计量比的综合排序显示:第1轴、第2轴的解释程度分别为58.89%和19.43%,可累计解释其总信息量的78.32%,表明可信度较高,但整体指标间的相关性较弱,说明4种荒漠短命植物生长过程中的化学计量比并未对生物量分配起决定作用,可能是由于干旱环境下植物的不同生存策略所引起的结果,或生物量分配的主要占比因素可能是植物自身遗传所决定的。  相似文献   

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In a previous experiment, rabbits and goats were immunized with boiled and ethanol precipitated (BE) bovine kidney antigen, and the specificity of the antibodies produced was compared (Andersen 1975). The caprine sera were species specific while the rabbit sera, however, cross-reacted with BE antigens from other ruminant species. Sera from 2 rabbit littermates differed somewhat in that 1 serum seemed to be mainly species specific giving only weak reactions against BE antigens from kidney and spleen from other ruminants, whilst the other serum was more organ specific and reacted equally with homologous and heterologous kidney antigens.  相似文献   

20.
我国共有5种水韭,全部被列为国家一级保护,均属极度濒危级(CR)野生植物。就营养器官而言,因水韭根、茎的简化,叶片特征成为最重要的分类学依据。本文针对形态特征相近的中华水韭、云贵水韭、台湾水韭和东方水韭,用显微镜观察了叶片发育的形态特征。结果表明:不同种水韭叶片在旋转角度、气孔分布等方面存在差异,而气孔器的种间一致性较高;同种水韭叶片在不同发育时期,其近远轴面的气孔指数、气孔分布及叶凸指数均有稳定的分类价值。本文检索讨论了我国4种水韭的分类学关系,并发现了叶表皮都存在异形条状细胞。  相似文献   

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