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 31 毫秒
1.
Remarkable similarities have been found in the pheromonal communication of Phyllotreta vittula Redtenbacher and of Ph. cruciferae Goeze (European population) (Coleoptera, Chrysomelidae). In previously published European field tests with Ph. cruciferae, only the major male‐produced sesquiterpene identified from North American Ph. cruciferae [compound A , (6R,7S)‐2,2,6,10‐tetramethylbicyclo[5.4.0]undeca‐1(11),9‐diene] was behaviourally active; unexpectedly, the European species Ph. vittula also responded in these tests and in the same way. In the present study, both the European population of Ph. cruciferae and Ph. vittula were shown to produce the same blend of compounds found in North American Ph. cruciferae and in similar proportions. Compound A is concluded to be a pheromone component for Ph. vittula as well as for Ph. cruciferae. In previously published tests with host compounds, Ph. vittula preferred 3‐butenyl isothiocyanate to allyl isothiocyante whereas the reverse was true for Ph. cruciferae. It was also learned earlier that compound A enhanced the response of both species toward allyl isothiocyanate. The present study further explored interactions between compound A and the two isothiocyanates. Thus, the highest catches of Ph. vittula were recorded in traps with the combination of racemic compound A with 3‐butenyl isothiocyanate, while highest Ph. cruciferae catches (and of Ph. nigripes Fabr.) were observed in traps with the combination of compound A with allyl isothiocyanate. Therefore, with the optimal combination of pheromonal and host‐derived stimuli, more specific communication channels may exist for the different Phyllotreta spp. Both Ph. cruciferae and Ph. vittula rank among the most important pest flea beetles in Europe.  相似文献   

2.
The parasitoid complexes of 22 species of the genus Phyllonorycter reared from 20 host plants were studied in the Middle Volga Basin. From a total of 124 host-parasitoid associations analyzed, 88 had been previously unknown. Minotetrastichus frontalis, Sympiesis sericeicornis, Pnigalio soemius, Closterocerus formosus, and S. gordius were the most frequent species. The highest percentage of parasitoids reared was observed in Ph. ulmifoliella (58.6%) and Ph. sylvella (54%), and the lowest one, in Ph. salictella (15%). Ph. corylifoliella (95.7%), Ph. populifoiella (95.5%) and Ph. insignitella (95.5%) had the highest mortality due to parasitoids. The number of endoparasitoid species prevailed over that of ectoparasitoids in the parasitoid complexes of the genus Phyllonorycter, but the number of individuals reared was 4 times greater for ectoparasitoids. The parasitoid complexes were the most similar in Ph. harrisella and Ph. quercifoliella on Quercus robur. The gregarious ectoparasitoid M. frontalis predominated over parasitoids of Phyllonorycter.  相似文献   

3.
Phoberomys is a giant caviomorph rodent included in the extinct Neoepiblemidae. It is recorded in the late Miocene-Pliocene of South America (Argentina, Venezuela, Brazil and Peru), and is one of the largest rodents that have ever lived. In this contribution we study specimens of Phoberomys from the ‘Mesopotamiense’, late Miocene of Entre Ríos Province (Argentina), including several unpublished specimens and the holotypes of the five nominal species (Ph. burmeisteri, Ph. praecursor, Ph. insolita, Ph. lozanoi and Ph. minima) previously recognised for this unit. Our study indicates that all Mesopotamian specimens belong to Phoberomys burmeisteri, and that the differences among them reveal individual and ontogenetic variation. Our phylogenetic analysis indicates that Neoepiblemidae is monophyletic and includes Phoberomys, Neoepiblema, and Perimys. Phoberomys species are recovered as a clade, which is more closely related to Neoepiblema than to the Patagonian Perimys. In addition, our study shows that Eusigmomys is not a Neoepiblemidae, but a Dinomyidae.  相似文献   

4.
The lipid fraction of seeds from different pine species and populations was studied regarding total lipid content, fatty acid profile and vitamin E composition. The investigated seeds contained a high percentage of lipid (13.6 to 31.5 %). Lipid fractions were found to be rich in vitamin E, which varied significantly among species and populations. P. halepensis (Ph−Hn) showed the highest content of vitamin E (256.3 mg/kg of seeds) and the uppermost content of α-tocopherol (44 mg/kg). However, P. halepensis (Ph−Kas) was the richest in γ-tocopherol (204.9 mg/kg). Lipid fractions had a low content of δ-tocopherol (1.2 to 3.6 mg/kg. The highest content of γ-tocotrienol (∼18 %) was determined for P. halepensis (Ph−Dc and Ph−Hn). Thirteen fatty acids were identified by GC-FID with significant variation between the investigated species. The linoleic acid was the major fatty acid followed by oleic acid and palmitic acid. The chemical differentiation among species for the composition of fatty acids and vitamin E was confirmed by PCA. Significant correlations were observed between the content of vitamin E and fatty acids and ecological parameters of P. halepensis populations.  相似文献   

5.
Parasitoid complexes of two species of the genus Phyllonorycter (Ph. apparella and Ph. populifoliella) reared from 2 plants (Populus tremula and P. nigra) were studied in Ul’yanovsk Province, Russia. Twenty species of parasitoids are new for Ph. apparella and 12 are new for Ph. populifoliella. Minotetrastichus frontalis and Pnigalio agraules are the dominant species for both parasitoid complexes. The highest relative abundance was observed for Ph. apparella on Populus tremula (75%) and for Ph. populifoliella on P. nigra (61%). The parasitoid complexes of Ph. apparella and Ph. populifoliella show high similarity (the Jaccard coefficient is 0.65).  相似文献   

6.
The haploid chromosome number of the South American butterfly Philaethria dido varies from 12 to 88. Eight different numbers have been found in this species complex. The related Ph. pygmalion and Ph. wernickei usually show only n=29, a very frequent number in the Lepidoptera; numbers of n=15 and n=21 for these species need confirmation. The most common chromosome number for Ph. dido is also the highest, n=88, and is found in many parts of northern and central Brazil on the Amazon river and its tributaries, as well as adjacent parts of other countries. The other numbers were observed mainly in northern South America and along the east coast. Two very different numbers were found together in four localities. We did not find specimens with meiotic features suggesting hybridization between individuals with different chromosome numbers. The diverse numbers in Ph. dido may belong to good sibling species, distinguishable externally by very minor characters. Since Ph. dido is a very primitive species in the tribe Heliconiini, dating probably from the early Tertiary, it probably has had many opportunities to undergo divergent chromosome evolution in isolation. Its strong, high flight and broad ecological valence would then permit rapid spreading out and coexistence of different chromosome forms, which in some cases have been noted to show diverse behaviour in the field.Dedicated to Professor Hans Bauer on the occasion of his eightieth birthday  相似文献   

7.
In the past decade, leishmaniasis seems to be re-emerging in Balkan countries. There are serious implications that Kosovo is a visceral leishmaniasis endemic region with autochthonous transmission; nevertheless, surveillance of vectors, reservoirs or the disease is not yet established. Gaining knowledge about sandfly vector species is a prerequisite for the development of a monitoring and control plan in the future. After a long gap in research of over 70 years, sandfly studies in Kosovo were resumed in 2014. During this presence/absence study, nine sandfly species were detected: Phlebotomus papatasi, Ph. perfiliewi, Ph. tobbi, Ph. neglectus, Ph. simici, Ph. balcanicus, Ph. alexandri, Ph. mascittii and Sergentomyia minuta. Three species are new with regard to the fauna of Kosovo – Ph. alexandri, Ph. balcanicus and Ph. mascittii. Besides increased diversity, changes in the number of collected specimens and distribution range of species were recorded, with Ph. neglectus being the most dominant species with the widest distribution. Testing of randomly chosen females for Leishmania spp. DNA resulted the in detection of L. tropica in a specimen of Ph. neglectus. The presence of numerous vector species in the sandfly fauna of Kosovo pose a threat for the re-emergence of vector-borne diseases. Therefore, continuous surveillance is recommended with regular updates on vector distribution and abundance.  相似文献   

8.
Abstract

«Phagnalon metlesicsii», a new species from Western Sicily, with a survey of the «Ph. rupestre» — group in the Mediterranean Region. — Phagnalon metlesicsii, a new species of the complex Ph. rupestre — Ph. graecum, is described. It is entirely glabrous and occurs in Western Sicily (M. Cofano) on vertical limestone rocks, nearly 200 mts. above the sea, in community with a flora particularly rich on endemics. The variability of the whole complex is discussed and some infraspecific taxa are proposed.  相似文献   

9.
Three new species of the genus Phytocoris, subgenus Soosocapsus, Phytocoris kalidii sp. n., Ph. reaumuriae sp. n., and Ph. kozlovi sp. n., are described from Mongolia. Two species, Phytocoris nitrariae Xu et Zheng, 1997 and Ph. jorgitooi Kerzhner et Schuh, 1995, are recorded from Mongolia for the first time.  相似文献   

10.
Among four species of Phytophthora tested, only Ph. capsici and Ph. tropicalis showed the same length for DNA sequence for both internal transcribed spacer (ITS)1 and ITS2 of ribosomal DNA. Phytophthora palmivora and P. nicotianae have lengths different from each other, and from the other two species. Although A1 and A2 types of Ph. capsici differ from each other by only one nucleotide, there are 10 different nucleotides between A1 and A2 types of Ph. tropicalis. Phylogenetic analysis of combined ITS sequences identified four clades each consisting A1 and A2 mating types of same species. The neighbor‐joining and maximum parsimony trees show that Ph. tropicalis (A2) is clustered with the clade of two isolates of Ph. capsici before joining the clade of A1 and two other isolates of Ph. tropicalis from GenBank. Our results support the separation of Ph. tropicalis and demonstrate the need to sequence more than a single isolate of a species in the study of molecular phylogeny of Phytophthora. The phylogenetic trees also suggest that Ph. tropicalis (A2) may represent a transitional isolate in the process of species evolution.  相似文献   

11.
Summary Fourteen of the 20 species recorded from Africa are resdescribed and illustrated. Of the remaining six species, four, namely, Cooperia borgesi, C. hippotragusi, C. minor and C. reduncai are considered species inquirendae and one, C. africana, is a possible synonym of C. punctata. The validity of C. oncophora and C. surnabada is discussed. A key to 16 species is given.Part of a thesis approved by the University of London for the award of a Ph.D. degree.Part of a thesis approved by the University of London for the award of a Ph.D. degree.  相似文献   

12.
Seasonal change of the base plasma level of testosterone and cortisol in males and progesterone, estradiol, and cortisol levels in females were analyzed in three Phodopus species: Ph. campbelli (Campbell’s hamster), Ph. sungorus (Djungarian hamster), and Ph. roborovskii (Roborovskii dwarf hamster). Our results showed a significant difference in the seasonal plasma level of testosterone and cortisol in males and cortisol in females of all Phodopus species, though the rhythms of breeding activity were similar. The results are discussed in the context of adaptive differences between hormonal patterns of more evolutionarily modern species (Campbell’s hamster and Djungarian hamster) and the more evolutionarily old Roborovskii dwarf hamster, the phylogenic position of which is currently under discussion.  相似文献   

13.
Summary Three human saliva genetic markers, namely, salivary peroxidase (SAPX), Pm, and Ph proteins, were investigated in the three major ethnic groups of Malaysia: Malays, Chinese, and Indians.For Pm, the allelic frequencies of Pm + for Malays, Chinese, and Indians are 0.385±0.030, 0.282±0.026, and 0.289±0.026 respectively. For Ph, the allelic frequencies of Ph + are 0.082±0.016 for Malays, 0.109±0.017 for Chinese, and 0.062±0.013 for Indians. For SAPX, the allelic frequencies of SAPX 1 in Malays, Chinese, and Indians are 0.762±0.027, 0.755±0.027, and 0.723±0.026 respectively.  相似文献   

14.
A universal set of equations for determining chlorophyll (Chl) a, accessory Chl b, c, and d, and total Chl have been developed for 90 % acetone, 100 % methanol, and ethanol solvents suitable for estimating Chl in extracts from natural assemblages of algae. The presence of phaeophytin (Ph) a not only interferes with estimates of Chl a but also with Chl b and c determinations. The universal algorithms can hence be misleading if used on natural collections containing large amounts of Ph. The methanol algorithms are severely affected by the presence of Ph and so are not recommended. The algorithms were tested on representative mixtures of Chls prepared from extracts of algae with known Chl composition. The limits of detection (and inherent error, ±95 % confidence limit) for all the Chl equations were less than 0.03 g m−3. The algorithms are both accurate and precise for Chl a and d but less accurate for Chl b and c. With caution the algorithms can be used to calculate a Chl profile of natural assemblages of algae. The relative error of measurements of Chls increases hyperbolically in diluted extracts. For safety reasons, efficient extraction of Chls and the convenience of being able to use polystyrene cuvettes, the algorithms for ethanol are recommended for routine assays of Chls in natural assemblages of aquatic plants.  相似文献   

15.
A study was made of the refolding of bacterial luciferases of Vibrio fischeri, V. harveyi, Photobacterium phosphoreum, and Photorhabdus luminescens. By reaction rate, luciferases were divided into two groups. The reaction rate constants of fast luciferases of V. fischeri and Ph. phosphoreum were about tenfold higher than those of slow luciferases of Ph. luminescens and V. harveyi. The order of increasing luciferase thermostability was Ph. phosphoreum, V. fischeri, V. harveyi, and Ph. luminescens. The refolding of thermoinactivated luciferases completely depended on the active DnaK–DnaJ–GrpE chaperone system. Thermolabile fast luciferases of V. fischeri and Ph. phosphoreum showed highly efficient rapid refolding. Slower and less efficient refolding was characteristic of thermostable slow luciferases of V. harveyi and Ph. luminescens. Chaperones of the Clp family were tested for effect on the efficiency of DnaK-dependent refolding of bacterial luciferases in Escherichia coli cells. The rate and extent of refolding were considerably lower in the clpB mutant than in wild-type cells. In E. coli cells with mutant clpA, clpP, of clpX showed a substantially lower luciferase refolding after heat shock.  相似文献   

16.
Summary Only Stephanopharynx compactus Fischoeder, 1901 is considered valid under the genus Stephanopharynx Fischoeder, 1901 and S. secundus Stunkard, 1929 and S. coilos Dollfus, 1963 are regarded as its synonyms. The species is redescribed and illustrated based on new material and scanning electron photomicrographs of its tegumental surfaces and the internal surface of its pharyngeal pouch are provided. Balanorchis anastrophus Fischoeder, 1901, the one and only species of the genus Balanorchis Fischoeder, 1901 is redescribed and illustrated. Photomicrographs of its tegumental surfaces as revealed by scanning electron microscopy are given. Additional information on Bilatorchis papillogenitalis Eduardo, 1980 is included. Part of a thesis approved by the University of London for the award of the Ph.D. degree. Part of a thesis approved by the University of London for the award of the Ph.D. degree.  相似文献   

17.
Allopolyploid wheat (Triticum aestivum L.) carries three pairs of homoeologous genomes but its meiotic pairing is diploid-like. This is the effect of the Ph (pairing homoeologous) system which restricts chromosome pairing to strictly homologous. Ph1 is the locus with the strongest effect. Disabling Ph1 permits pairing between homoeologues and is routinely used in chromosome engineering to introgress alien variation into breeding stocks. Whereas the efficiency of Ph1 and the general pattern of homoeologous crossovers in its absence are quite well known from numerous studies, other characteristics of such crossovers remain unknown. This study analyzed the crossover points in four sets of the ph1b-induced recombinants between wheat homologues as well as between three wheat and rye (Secale cereale) homoeologous chromosome arms, and compared them to crossovers between homologues in a reference wheat population. The results show the Ph1 locus also controls crossing over of homologues, and the general patterns of homologous (with Ph1) and homoeologous (with ph1b) crossing over are the same. In all intervals analyzed, homoeologous crossovers fell within the range of frequency distribution of homologous crossovers among individual families of the reference population. No specific DNA sequence characteristics were identified that could be recognized by the Ph1 locus; the only difference between homologous and homoeologous crossing over appears to be in frequency. It is concluded that the Ph1 locus likely recognizes DNA sequence similarity; crossing over is permitted between very similar sequences. In the absence of Ph1 dissimilarities are ignored, in proportion to the level of the sequence divergence.  相似文献   

18.
Cultivated wheat Triticum turgidum is an allotetraploid (AABB) with diploid-like behaviour at metaphase I. This behaviour is mainly influenced by the action of the Ph1 locus. To study the effect of Ph1 on chromosome pairing in T. turgidum we have analysed the synaptic pattern in fully traced spread nuclei at mid- and late-zygotene and at pachytene of three different genotypes: a standard line, ph1c mutant and a duplication mutant, with zero, two and four doses of Ph1, respectively. The number of synaptonemal complex (SC) bivalents and of the different SC multivalent associations were determined in each nucleus. The mean number of lateral elements involved in SC multivalent associations (LEm) at mid-zygotene was relatively high in all lines and was similar in two and zero doses of Ph1. These means changed little with the progression of zygotene but decreased at pachytene because of the transformation of multivalents into bivalents. Multivalent correction was more efficient in the presence than in the absence of Ph1. The four doses of Ph1 genotype showed a higher number of SC bivalents at mid-zygotene, and the frequency of multivalents decreased progressively throughout zygotene and pachytene. The results suggest that the main action of the Ph1 locus on the diploidisation mechanism would be related to a process of checking for homology operating during prophase I. Received: 27 February 2000 / Accepted: 12 July 2000  相似文献   

19.

The Gracillariidae fauna of Siberia, the region that occupies almost half of the territory of the Russian Federation, remains poorly studied. During a DNA barcoding study of Gracillariidae in Siberia, based on analysis of larvae and pupae collected from their leaf mines on woody plants, we identified 41 species. Three gracillariids were identified only to genus: Caloptilia sp. (host plant Prunus padus), Parornix sp. (Malus sp.), and Phyllonorycter sp. (Crataegus sp.), representing poorly studied or undescribed species. Six species are reported here for the first time for Siberia: Callisto insperatella (from Novosibirsk and Tomsk provinces), Caloptilia alnivorella (Buryatia), Phyllonorycter ermani (Irkutsk Province), Ph. lantanella (Novosibirsk Province), Ph. pumilae (Omsk and Irkutsk provinces), and Ph. viciae (Krasnoyarsk Territory). Parornix pfaffenzelleri, found in Khakassia, is reported as a species new to Russia. Other 15 gracillariid species previously known from Siberia were recorded in new administrative regions. The invasive lime leafminer Phyllonorycter issikii was first documented in Tomsk Province and Krasnoyarsk Territory in 2017 and 2018, respectively. Seven new gracillariid-host plant associations were found: Parectopa ononidis on Lupinaster pentaphyllus, Sauterina hofmanniella on Lathyrus gmelinii, Caloptilia stigmatella on Salix kochiana, Callisto insperatella on Prunus virginiana, Parornix scoticella on Amelanchier sp., Phyllonorycter ermani on Alnus alnobetula subsp. fruticosa, and Phyllonorycter viciae on Vicia unijuga. The Gracillariidae fauna of Siberia has 51% similarity with that of European Russia and only 38% similarity with that of the Russian Far East.

  相似文献   

20.
赖广辉 《广西植物》2018,38(9):1215-1220
该文根据采自华东地区的一些刚竹属植物居群中的可靠花枝标本,结合现场调查和形态解剖观察,描述和增补了白哺鸡竹、瓜水竹、谷雨竹、云和哺鸡竹的花序、假小穗和花部形态特征,并提供了显示花枝外貌和花器官主要特征的照片。瓜水竹的花序呈头序,小花较短,应属于水竹组;而其余3种的花序呈穗状,小花较长,应归隶刚竹组。所有的凭证标本均保存于安徽省广德县林业科学研究所竹类标本室中。  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