首页 | 本学科首页   官方微博 | 高级检索  
相似文献
 共查询到20条相似文献,搜索用时 15 毫秒
1.
Summary. Transferrin variants were examined in population samples of fish, locally known as jaraquis, Semaprochilodus taeniurus and 5. insignis. Both species were sampled on two occasions from two geographical areas in the Amazon region. The two species showed no common transferrin type. The 122 specimens of S. taeniurus showed three genotypes encoded by two codominant alleles at the transferrin gene locus ( Tf ). The 69 specimens of S. insignis showed another two transferrin alleles. Hence the different Tf genotypes support their taxonomic differences, and are predictably capable of identifying any suspected hybrid species. No hybrid was found.  相似文献   

2.
喀斯特峰丛洼地不同退耕还林还草模式的土壤微生物特性   总被引:11,自引:0,他引:11  
以坡耕地为对照,研究了喀斯特峰丛洼地任豆、香椿、板栗、柑橘、任豆+桂牧1号、桂牧1号和撂荒7种常见退耕还林还草模式下土壤微生物种群数量、微生物量碳氮磷及其分形特征和主要土壤酶活性特征。结果表明,不同退耕还林还草模式土壤微生物种群数量组成不同,除任豆模式外其他退耕还林还草模式均能提高土壤微生物总数量;不同退耕还林还草模式(除任豆模式外)土壤微生物量碳(MBC)含量极显著增加,撂荒地最高,土壤微生物量氮(MBN)含量变化范围不大,呈下降趋势,土壤微生物量磷(MBP)含量的变异很大,香椿、板栗、撂荒和桂牧1号模式显著或极显著高于坡耕地;土壤MBC与细菌数量的关系最相关(D=-4.07,R=0.81,P<0.01),其次为MBC与放线菌数量(D=3.82,R=0.44,P<0.05),再次为MBN与真菌数量(D=0.58,R=0.61,P<0.01),MBC与真菌数量、MBN与细菌、放线菌数量以及MBP与细菌、真菌、放线菌数量之间不存在分形关系;不同退耕还林还草模式(除桂牧1号模式外)均显著或极显著增加了土壤蔗糖酶、脲酶和磷酸酶活性。总之,不同退耕还林还草模式均改善了土壤微生物特性,为喀斯特峰丛洼地脆弱生态系统恢复与重建提供了重要依据。  相似文献   

3.
详细研究了冯澄如创作的一幅彩色植物绘画。结果表明其中的植物是豆科植物任公豆(即任豆)Zenia insignis Chun。1946年陈焕镛为纪念著名学者任鸿隽而以其名字命名建立了任公豆(即任豆)属,并由冯澄如进行彩色绘画,胡先骕为赞颂此事在画中赋诗《任公豆歌》。介绍了与此画相关的我国近代植物分类学的奠基人胡先骕、陈焕镛,我国近代植物科学绘画的奠基人冯澄如,以及我国近代科学的奠基人之一任鸿隽四人在植物科学发展工作中的履历。这幅《任公豆图》生动地表现出了四位科学工作者的友好情谊和杰出贡献。  相似文献   

4.
为了研究标志链带藻(Desmodesmus insignis strain JNU24)在不同Na NO3浓度和不同废水浓度培养下的生长与代谢产物积累状况,评估标志链带藻对废水的处理能力,本研究利用柱状光反应器对标志链带藻进行培养,分别对4种Na NO3浓度的BG-11培养基和4种废水浓度培养下藻细胞的生物量、蛋白质含量、碳水化合物含量和淀粉含量进行了测定。结果显示,在BG-11培养基中,氮浓度为9.0 mmol/L时,藻细胞生物质浓度最高,达6.23 g/L;在废水培养下,未稀释的原废水实验组,其藻细胞生物质浓度最高,达10.31 g/L;75%废水培养下,藻细胞的淀粉含量最高(达50.9%),单位体积藻细胞淀粉含量和产率分别为4.86 g/L和405 mg·L~(-1)·d~(-1),且显著高于不同浓度Na NO3的BG-11培养基组。本研究还测定了标志链带藻对废水中氮、磷的去除效率,结果显示不同浓度废水培养下,氮、磷的去除效率最高可达90.8%和98.7%。基于柱状反应器中的最佳培养效果,以9.0 mmol/L Na NO3的BG-11培养基和75%废水于3.0 cm光径平板光生物反应器中进行室内扩大培养,结果显示在75%废水培养下,藻细胞生物质浓度达9.75 g/L,淀粉单位体积含量和产率分别达到4.75 g/L和230 mg·L~(-1)·d~(-1),且为9.0 mmol/L Na NO3的BG-11培养基培养的3倍。通过沉降特性分析发现,藻细胞收获90 min后均完全沉降,具有较强的沉降性能。本研究标志链带藻能够耐受废水中较高的氮、磷浓度,且对废水中氮、磷有显著的去除作用;该藻能利用废水中的营养成分积累较高的生物量和淀粉含量并且藻细胞能快速沉降,具有极高的经济价值和应用价值,是一株淀粉生产能力较高和废水处理能力较强的极具开发潜力的藻株。  相似文献   

5.
The nature of female-limited mimicry in the myrmecomorphic plant bug Coquillettia insignis Uhler is described, including aspects of its relation to possible ant models and to co-occurring visual arthropod predators. Twelve species of ants were collected with C. insignis on its host plant Lupinus caudatus Kell., of which six species were common: third instar to adult female mimics closely resemble four of these six species, in both morphology and behaviour. The mimetic significance of these close correspondences is indicated by the results of over 500 feeding trials, using the three most common species of co-occurring visual arthropod predators as operators. Two of these three species (Sussacus papenhoei Gertsch: Salticidae; and Sinea diadema (Fabricius): Reduviidae), classified C. insignis with corresponding models and not with closely related, non-mimetic plant bugs. Furthermore, after having had a single 'unpleasant' experience with the ant Formica fusca assassin bugs that had previously accepted C. insignis as prey rejected them in 19 out of 23 trials. These findings indicate that C. insignis is a Batesian mimic, with visual arthropod predators functioning as one class of potential operator. Implications for future research on perception and learning in arthropod predators is briefly discussed.  相似文献   

6.
The trophic relationships of 13 intertidal fish species collected in northern Chile (20 degrees 18' S and 20 degrees 54' S) from July 1997 to July 1998, the stomach content analysis of 820 specimens, were investigated. The importance of the prey items was assessed by means of gravimetric and frequency of ocurrence methods, together with the Shannon-Wiener (trophic diversity) and Pianka (trophic overlap) indexes. The results allowed to recognize a fish assemblage composed of: 46% of carnivorous species, preying mainly on porcelain crabs. polichaetes and minor crustaceans: 23% of herviborous species, preying mainly on chlorophitic algae: 31% of omnivorous species. preying mainly on chlorophitic algae. Copepoda and Gastropoda. The carnivorous fishes Cheilodactylus variegatus. Helcogrammoides chilensis. Labrisomus philippii and the omnivorous Oplegnatus insignis showed euriphagic tendencies (>2.0 bits), however, the major trophic overlap (>0.90) was observed among herbivorous and omnivorous fishes. Finally, the increase of fish species towards lower latitudes and the increase of herbivory and omnivory levels in the rocky intertidal shore were analyzed.  相似文献   

7.
Specimens of peripatopsid Onychophora from New Zealand (the viviparous Peripatoid.es novaezealandiae and P. suteri and the oviparous Ooperipatellus insignis) have been analysed by allozyme electrophoresis and compared with three species of viviparous peripatus and 0. insignis from Australia. The data indicate that at least two species of Peripatoides are present, in addition to those described. Populations collected from Dunedin, in the South Island, are not referable on morphological grounds to any described genus. Furthermore, specimens exhibit such a high level of genetic distinctiveness that we speculate they have diverged from the Peripatoides and Euperipatoides lineages prior to the separation of Australia and New Zealand some 95 Myr ago. Specimens referable to 0. insignis from New Zealand are genetically quite distinct from 0. insignis at its type locality in Australia and must be considered endemic.  相似文献   

8.
A new myxosporean species is described from the fish Semaprochilodus insignis captured from the Amazon River, near Manaus. Myxobolus insignis sp. n. was located in the gills of the host forming plasmodia inside the secondary gill lamellae. The spores had a thick wall (1.5-2 microm) all around their body, and the valves were symmetrical and smooth. The spores were a little longer than wide, with rounded extremities, in frontal view, and oval in lateral view. They were 14.5 (14-15) microm long by 11.3 (11-12) microm wide and 7.8 (7-8) microm thick. Some spores showed the presence of a triangular thickening of the internal face of the wall near the posterior end of the polar capsules. This thickening could occur in one of the sides of the spore or in both sides. The polar capsules were large and equal in size surpassing the midlength of the spore. They were oval with the posterior extremity rounded, and converging anteriorly with tapered ends. They were 7.6 (7-8) microm long by 4.2 (3-5) microm wide, and the polar filament formed 6 coils slightly obliquely to the axis of the polar capsule. An intercapsular appendix was present. There was no mucous envelope or distinct iodinophilous vacuole.  相似文献   

9.
三种木莲属(木兰科)植物的核型研究   总被引:5,自引:0,他引:5  
为探讨巴东木莲 (Manglietiapatungensis)的分类学地位 ,对巴东木莲以及它的近缘种红花木莲 (M insignis)和乳源木莲 (M yuyuanensis)进行了核型研究。乳源木莲和巴东木莲的核型公式为 2n =34m (2sat) 4sm ,红花木莲的为 2n =32m 6sm (2sat)。结合前人的研究说明木莲属的核型比较稳定 ,核型不对称性均为较对称的 2B型 ,只是在核型不对称系数、染色体相对长度、最长染色体与最短染色体比值等方面有细微差异。红花木莲和巴东木莲的核型为首次报道。核型分析结果不支持将巴东木莲归并到红花木莲中的分类学处理  相似文献   

10.
Dracunculus insignis is a nematode parasite that infects the subcutaneous tissues of mammals such as raccoon (Procyon lotor), mink (Neovison vison) and fisher (Martes pennanti). D. lutrae, a morphologically similar species, has only been recovered from the otter (Lontra canadensis). Species identification of these two North American guinea worms has only been achieved by morphology of males and host identity. As a result, where only female specimens are present, accurate identifications are not possible. To date, specimens recovered from otter have been assumed to be D. lutrae, while those from all other hosts are assumed to be D. insignis. This study uses DNA barcoding to differentiate between these two North American dracunculoids. Our results show that D. insignis is a 'true' generalist, showing little sequence divergence regardless of host association, although our studies did validate its occurrence in a new host - the otter. Interestingly, specimens of the host specialist, D. lutrae, showed some sequence divergence, although it was low. The finding of D. insignis in otter substantiates the need to supplement morphology-based methods in providing species identifications for certain dracunculoids.  相似文献   

11.
任豆林的生物量和光能利用率   总被引:11,自引:0,他引:11       下载免费PDF全文
 本文研究了粤北石灰岩地区以任豆(Zenia insignis)为主的自然林(萌生34年)的生产能力,并与任豆人工林(6年生)作对照。结果表明,在1992年7月调查时,自然林和人工林的现存生物量分别是125.38和10.34t·hm-2;平均增长量为3.69和1.72t·hm-2·a-1;木材蓄积量为86.35和9.93m3·hm-2;其乔木层总生产力为84284和21510kJ·m-2·a-1;对光合有效辐射能的利用效率为5.43%和1.39%。反映了任豆自然林现存生物量和生产力比鼎湖山南亚热带常绿阔叶林(同龄萌生林,在1991年11月调查)现存生物量196t·hm-2低,而比热带和亚热带半干早区森林植物量分别107和98.7t·hm-2高。任豆人工林因盖度和叶面积指数比自然林低,故总生产力和光能利用率也比较低,说明任豆人工林尚有较高的生产潜力。  相似文献   

12.
The population size of SRB and TOB was enumerated at bimonthly intervals from water and sediment samples of six fish ponds (polyculture, monoculture and traditional systems) over a period of two and a half years. Density of SRB and TOB was maximal in polyculture and minimal in traditional systems of fish farming. Using sine and cosine waves of periodic functions or polynomial equations of high order, seasonal changes in the numbers of SRB and TOB were represented; the former occurred in largest numbers in summer while the latter in winter. Step wise multiple regression analysis revealed that organic carbon, organic matter, phosphate and different forms of N were important attributes to the seasonal changes of SRB and TOB in these fish ponds.  相似文献   

13.
濒危植物红花木莲大孢子发生和雌配子体发育的研究   总被引:7,自引:0,他引:7  
潘跃芝  龚洵 《西北植物学报》2002,22(5):T001-T003
研究了濒危植物红花木莲(Manglietia insignisBl)的大孢子发生和雌配子体的发育,红花木莲每朵花心皮数为48-73枚,每心皮内胚珠数4-8颗不等,多数是6颗或8颗,胚朱倒生,双珠被,厚珠心,大孢子四分体线形排列,功能大孢子位于合点端,胚囊发育为蓼型。胚珠具珠孔塞,成熟胚囊的卵细胞败育率高达79.1%。这是造成栽培红花木莲结籽率低的主要原因,较低的结籽率影响了红花木莲迁地保护的有效性。  相似文献   

14.
岩溶石漠化地区几种生态恢复植物的生理生态学特征   总被引:10,自引:0,他引:10  
何成新  黄玉清  李先琨  王晓英  汪青   《广西植物》2007,27(1):53-61,126
选择石漠化地区树种任豆树、金银花和苦丁茶的植株为对象,测定其光响应曲线和光合、蒸腾、气孔导度的日变化,研究其光合、蒸腾、气孔导度与环境因子间的关系。在岩石裸露率高、地表水缺乏、白天温度极高的石漠化地区,对任豆和苦丁茶进行光响应模拟表明,两者的最大净光合速率分别为15.88μmol.m-2.s-1、4.58μmol.m-2.s-1。从气体交换特征日变化看出,这三种植物均有光合午休现象,任豆午休程度最弱而苦丁茶最强,光合与气孔导度均呈显著的正相关关系;通过对胞间CO2浓度Ci与气孔限制Ls关系分析,任豆和金银花的光合作用上午以气孔限制为主,下午有非气孔因素影响,而苦丁茶则以非气孔限制为主。任豆树具有较高的水分利用效率,金银花次之,而苦丁茶最小。通过综合分析,认为地表缺水并不是石漠化地区简单唯一的限制因子,高温胁迫也造成该区植物同化CO2减少的原因。根系的下扎能力也应是石漠化地区植物长期存活的关键。因此通过人工诱导构建石漠化地区植物群落时一定要考虑植物本身的根系遗传性状。  相似文献   

15.
Although the karyotypes of twelve species of Dieuches Dohrn, 1860 belonging to Rhyparochrominae have been described so far, there is no information about heterochromatin and its characterization in terms of base composition for any of the species. In the present paper, C-banding and fluorescent banding have been applied for the first time to three species of Dieuches : D. uniguttatus, D. insignis (2n = 12 = 8A + 2m + XY) and D. coloratus (2n = 14 = 10A + 2m + XY). Dieuches uniguttatus and D. insignis show distinct terminal C-bands along with a few interstitial bands in all the autosomal bivalents, whereas in D. coloratus , one autosomal pair is almost completely heterochromatic, three show C-positive bands while one is totally euchromatic. The sex chromosomes too show heterogeneity in distribution of C-heterochromatin among three Dieuches species. Characterization of heterochromatin in D. uniguttatus and D. insignis using DAPI/CMA3 staining reveals that in D. uniguttatus , C- heterochromatin blocks of all the autosomal bivalents, which are predominantly A–T rich, whereas in D. insignis , these are rich both in A–T and G–C. In D. uniguttatus, sex chromosomes X and Y have localized G–C rich regions whereas in D. insignis , these are scattered in X and absent in Y. As variations in the heterochromatin represent the main source of karyological differentiation among and within species, it seems that there occurred extensive redistribution of heterochromatin within the complement as the three species evolved. There is need for cytological details of more species to understand evolutionary aspects in the genus Dieuches .  相似文献   

16.
黄玉清  王晓英  陆树华  汪青  赵平   《广西植物》2006,26(2):171-177
针对西南岩溶石漠化地区干旱缺水的特点,采用Li-6400对其先锋树种任豆、金银花、狗骨木的光合、蒸腾及水分利用效率等特征进行分析,以揭示先锋树种利用水分生理生态学特征,从而提出植被恢复的对策。光响应模拟结果表明金银花和狗骨木符合Walker的非直线双曲线模型。蒸腾临界值狗骨木(幼树期)最小,金银花次之,任豆树较大,说明阳性树种任豆具有较大的蒸腾拉力,能够从土壤提取更多的水分,以减少岩溶石漠化地区强光引起的高温灼伤。任豆树、金银花、狗骨木具有同地带干性或沙漠优势植物的光合速率特征。任豆树有较耐受强光的能力,这与其在石漠化地区总是能够成为优势层片优势种的地位相符。三种植物光有效辐射与叶片蒸腾的呈极显著的线性关系;任豆树的蒸腾作用受气孔调节明显;狗骨木有较高的水分利用效率。上午9点左右和下午5∶00~6∶00是这些石漠化地区植物水分利用最高时间段。可以说这三种植物具有适应石漠化地区干旱和高温的生理生态学适应特征和避旱避高温策略,并保持旺盛的生物生产力。从植物固定碳水化合物效率并提高水分利用效率而言,三种植物套种,任豆树能够对藤灌植物适当遮荫,对加速狗骨木生长,提高金银花的产量将具有较好的效益。  相似文献   

17.
珍稀速生树种翅荚木的特性及开发利用(综述)   总被引:4,自引:0,他引:4  
介绍我国南方特有珍稀树种翅荚木(Zenia insignis)的自然分布、树种特性及育苗造林技术、综合利用等方面的研究概况,为今后开展相关研究提供参考。  相似文献   

18.
Population densities and generation time of heterotrophic bacteria were estimated in water and sediments of fish ponds used for polyculture, monoculture and traditional systems of fish farming over a period of two and a half years. Spatial differences in microbial densities in the ponds were related to the organic loadings of the farm site and farm management. A number of environmental factors such as nitrogen, dissolved organic carbon, bicarbonate and phosphate of water were found to be responsible for the seasonal changes of heterotrophic bacteria in these ponds.  相似文献   

19.
Lesions due to Dracunculus insignis in the legs of raccoons (Procyon lotor) in southern Ontario occur seasonally as most larvigerous females emerge in the spring and early summer (April-June). The pathology of dracunculiasis in the raccoon is described and the transmission of the parasite in the wild is discussed with respect to seasonality and local agricultural practices. Crayfish, fishes and frogs (including tadpoles) were given infective third-stage larvae of D. insignis to test their suitability as paratenic hosts. Most of the larvae fed to adult Rana pipiens and R. clamitans were recovered from the somatic musculature. Larvae had increased in size and were highly infective to raccoons.  相似文献   

20.
猫儿屎和三叶木通种子油中脂肪酸成分的GC-MS分析   总被引:3,自引:1,他引:2  
白成科 《西北植物学报》2007,27(5):1035-1038
采用索氏提取法提取木通科植物猫儿屎和三叶木通种子的脂溶性成分,甲酯化处理后用气相色谱-质谱联用技术(GC-MS)分离和鉴定其组成和含量。从猫儿屎种子油中鉴定出9种脂肪酸,占检出物总质量分数的94.67%(其中饱和脂肪酸占12.63%,不饱和脂肪酸占82.04%),主要成分为9-十六烯酸(47.22%)、9-油酸(27.13%)、棕榈酸(10.75%)、亚油酸(7.47%)和硬脂酸(1.61%)。从三叶木通种子油中鉴定出10种脂肪酸,占检出物总质量分数的99.75%(其中饱和脂肪酸占23.39%,不饱和脂肪酸占76.36%),主要成分为11-油酸(47.63%)、亚油酸(27.05%)、棕榈酸(20.14%)、16-甲基-十七烷酸(3.03%)和8-油酸(1.07%)。结果表明,猫儿屎和三叶木通种子油中脂肪酸含量丰富,在食用、医疗保健等方面具有较高的应用潜力和综合开发前景。  相似文献   

设为首页 | 免责声明 | 关于勤云 | 加入收藏

Copyright©北京勤云科技发展有限公司  京ICP备09084417号