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1.
《Journal of Natural History》2012,46(6):1467-1476
Rhodanese (EC 2.8.1.1) is a sulphurtransferase which catalyses in vitro the formation of thiocyanate from cyanide and thiosulphate or some other sulphur donor. One proposed function of this multifunctional enzyme in vivo is detoxification of cyanide.

Lotus corniculatus s.l. is genetically polymorphic for cyanogenesis. Here we present the first investigation of such a polymorphic species group for its rhodanese content.

Enzymatic thiocyanate formation was easily detected in the leaves of Lotus alpinus and L. corniculatus from various natural habitats in Switzerland. All samples taken from these two species were found to contain a higher level of rhodanese activity than samples from the leaves of the six cultivated higher plants examined. Most interestingly, the differences observed within the Lotus species appear to be correlated with the polymorphism of cyanogenesis: cyanogenic plants AcLi showed much higher rhodanese activities than the acyanogenic types Acli and acLi. This correlation suggests that rhodanese provides a mechanism to detoxify cyanide in cyanogenic plants.  相似文献   

2.
《Journal of Natural History》2012,46(6):1443-1460
Most populations of the legume Lotus corniculatus are polymorphic for the characters of leaf cyanogenesis and petal cyanogenesis. The distribution of these phenotypes was investigated in a section of chalk quarry where the vegetation ranged from pioneer species growing on almost bare chalk through to a mature grassland assemblage. The vegetation surrounding randomly chosen L. corniculatus individuals was recorded and this information was used to compare the environments in which the different phenotypes were growing. Leaf cyanogenic plants were found to occur at higher frequencies in grassland areas than in the more open conditions typical of earlier stages in the succession at the quarry. Factors that may be responsible for the distribution of the phenotypes are discussed.  相似文献   

3.
《Journal of Natural History》2012,46(6):1435-1441
Chromosome numbers and cyanogenesis were studied in 22 French populations of Lotus corniculatus/L. alpinus from the South-west Alps. L. corniculatus with 2n = 24 and L. alpinus with 2n = 12 proved to be polymorphic for cyanogenesis. The highest frequencies of HCN + individuals were generally found upon carbonate, in open vegetation and at high altitude. However, populations studied from various substrata in the upper valley of the Var consistently comprised fewer cyanogenic plants than the colonies occurring further to the south. The authors suggest that this distribution pattern might be influenced by the occurrence of ancestral populations of L. alpinus at Mount Ventoux and the Mountain of Lure.  相似文献   

4.
《Journal of Natural History》2012,46(6):1429-1433
An association between the frequency of the dark-keeled petal form of Lotus corniculatus and altitude is described from locations in the mountains of southcentral Europe. Some possible causes for the altitudinal clines are discussed.  相似文献   

5.
Artemisia carruthii and A. frigida of the subgenus Artemisia and A. filifolia and A. spinescens of the subgenus Dracunculus all have chromosome numbers based on x = 9. Diploid (2n = 18) karyotypes of each species are composed of large, medium, and small chromosomes that are mainly metacentric and submetacentric. The individual karyotypes are similar but distinctive. Artemisia filifolia ’s karyotype and chemistry is quite similar to that of Section Tridentatae, but A. filifolia has significant morphological differences with respect to the Tridentatae. Artemisia spinescens includes a tetraploid (2n = 36) population as well as diploid populations. Karyotypic analysis of a tetraploid A. spinescens suggests that it is an autotetraploid, thus carrying out a common theme in Artemisia (autopolyploidy).  相似文献   

6.
《Journal of Natural History》2012,46(19):1583-1596
Based on morphological characters, two species of the genus Zodarion, Z. hamatum and Z. italicum, were placed into the italicum group. The aim of this study was to evaluate similarity of these two species in respect of various aspects of their natural history and karyotypes. Both species had similar phenological patterns, being univoltine, but some specimens reached adulthood the same year before winter. Both representatives had nocturnal activity and were able to capture various ant species. Zodarion hamatum seems to be specialized on Myrmicinae ants, and Z. italicum on Formicinae ants. Zodarion hamatum showed more agile predatory behaviour than Z. italicum presumably due to specialization on Myrmicinae ants, which have lower population density. Both species are generalized mimics of bicoloured (orange‐dark brown) ants, such as Lasius emarginatus; they performed similar courtship and mating. The two study species exhibited contrasting reproductive strategies. Zodarion hamatum spiders had higher fecundity than Z. italicum as a result of larger body size but Z. italicum had larger eggs than Z. hamatum. This is presumably an adaptation to different availability of prey ants. Both species had the same diploid chromosome number, sex chromosome system and pattern of X chromosome heteropycnosis in testes. Results support a very close relationship between these two Zodarion species.  相似文献   

7.
《Journal of Natural History》2012,46(6):1543-1579
The species of the genus Labeo from the Lower Zaire river system have been revised on the basis of 284 preserved fishes, including type material of 18 nominal species cited or described from this region. Morphometrics, meristic counts, morphological observations and radiographs have been used for this study. All results obtained are supported by statistical analyses. From the 18 nominal species reported, only 12 species are recognized as valid. Two major groups were identified: one group has rows of conical papillae on the inner surface of lips; and the other group presents rows of transverse plicae on the inner surface of lips. The first group has two species: L. lineatus and L. weeksii. One synonymy is proposed: L. lineatus (partim) = L. weeksii. In the second group, 10 species have been identified: L. longipinnis, L. degeni, L. barbatus, L. macrostoma, L. falcipinnis, L. cyclorhynchus, L. parvus, L. greenii, L. nasus and L. sorex. One unidentified taxon apparently represents a species new to science, but this must be confirmed by a wider revision of the genus which is the subject of further research. Some synonymies in this group are proposed: L. brichardi (partim) = L. barbatus; L. lineatus (partim) = L. degeni. Other synonymies already established by Reid (1985), have been confirmed: L. lividus = L. barbatus; L. brichardi (partim) = L. macrostoma; L. variegatus = L. cyclorhynchus. One synonymy has been restored: L. velifer = L. longipinnis. Finally, one synonymy remains in question: L. chariensis = L. parvus. A key to species is provided.  相似文献   

8.
ABSTRACT

Species of the genus Platorchestia occur both in the northern hemisphere (18 species) and southern hemisphere (three species plus a synanthropically introduced species in South America and South Africa). The greater number of endemic Platorchestia species in the North Pacific Ocean suggests that it could be the epicentre of evolution for this genus. North-western Pacific Platorchestia includes 15 species which occupy five ecotopes: wrack (seven species), terrestrial leaf litter (five species), freshwater (one species), marsh (one species) and tentatively present in caves (one species). North-eastern Pacific Platorchestia includes only one putative driftwood specialist, with no other species found in North American coastal habitats. This compares with three good endemic Platorchestia species (plus two putative additional species) and only two ecotopes: wrack (three species) and freshwater (two species) from the North Atlantic Ocean, inclusive of the Gulf of Mexico and Mediterranean Sea. Insufficient data is available to consider Platorchestia zoogeography for the Arabian Sea and Bay of Bengal. Synanthropic dispersal involving Platorchestia in Polynesian outrigger canoes, or in solid ballast carried in the holds of wooden sailing ships has been identified as a potential complicating factor in the zoogeography of this genus. Platorchestia is proposed to have arisen on Laurasia and is therefore basically a northern hemisphere genus. Questions concerning Platorchestia zoogeography and evolutionary ecology are posed and two methods (more intensive field sampling and molecular genetics) are suggested to be the way to solve them.  相似文献   

9.
Three new aorid amphipod species from Tasmanian kelp holdfasts are described: Microdeutopus varietensis sp. nov., Lembos clematis sp. nov. and L. verrucularum sp. nov. Strong sub-ocular regression of the head is a usual feature of the genus Microdeutopus and is shown by M. varietensis. It is not, however, typical of the other known Australian/NewZealand Microdeutopus species (M. haswelli and M. apopo). The Tasmanian Lembos species (L. chiltoni, L. clematis and L. verrucularum) are not known from New Zealand, where the genus is represented by L. pertinax, L. acherontis and L. hippocrenes. The Tasmanian Lembos species display the condition of the mandibular palp that typifies the genus, that is, article 3 longer than article 2 (cf. the New Zealand species which display the reverse, unusual, condition).  相似文献   

10.
This paper describes a new species of gigantic terrestrial earthworm Metaphire taiwanensis sp. nov. from western Taiwan. It reached the maximum length of 860 mm for a living clitellate and 637 mm after preservation. It is an autochthonous species found in Mt Beidongyan and the Meifeng area of the Central Mountain Range at elevations of 1800–2100 m. M. taiwanensis is octothecate and protandric, characters shared by Metaphire stephensoni (Michaelsen) of Indochina, and Metaphire bununa Tsai, Tsai and Liaw and Metaphire paiwanna Tsai, Tsai and Liaw of Taiwan. These four species are combined as a new species-group called the stephensoni-group within the genus Metaphire Sims and Easton. It is closely related to the congeneric ignobilis species-group, which is also octothecate but holandric. It differs from holandric and quadrithecate Metaphire magna (Chen) of Hainan Island, in which the length also reaches 700 mm. Specific variation and evolutionary trends in sizes and segment numbers of the Pheretima genus-group are discussed.  相似文献   

11.
《Journal of Natural History》2012,46(33-34):2133-2143
ABSTRACT

A compilation of the ciliated suctorian species found on marine meiobenthic nematodes as epibiont has been carried out based on published records. It included the taxonomic position of each species of ciliate epibiont, the species of basibiont nematodes, the geographic zones where they have been found and the different records of these species together with the corresponding bibliographic references. Altogether 12 suctorian species were listed. Among registered suctorian species, Thecacineta oregonensis, T. urceolata, Trematosoma rotunda, Loricophrya bosporica, L. mediterranea, L. scanica, L. sivertseni, L. spitinae and L. stresemanni are likely specific to nematodes. The species as Thecacineta calix and Limnoricus ceter were found on a variety of hosts. Representatives of the genus Thecacineta reproduce by vermigemmic budding, swarmers of which are unable to swim, and often attached close to the cloaca of the nematodes. Any regularity in localization were not observed in the representatives of genera Trematosoma and Loricophrya, which form ciliary, swimming swarmers.  相似文献   

12.
The characters of the genus Lunulites Lamarck, and of some closely related genera are described and discussed. The genus Lunularia Busk is reintroduced, and three species from Australasia are described. One species, L. parvicella, is known only as an Australian Tertiary fossil, but the remaining two, L. capulus and L. repandus, have an extensive Tertiary-to-Recent Australasian distribution. L. capulus is apparently confined to Australian waters and deposits, but L. repandus has now been found in the Miocene and Recent of New Zealand, as well as off the southern and western Australian coasts.  相似文献   

13.
《Journal of Natural History》2012,46(16):1177-1212
The tanaidacean genus Chauliopleona Dojiri and Sieg, is reviewed. A generic diagnosis is given and the type species Chauliopleona dentata Dojiri and Sieg, is redescribed. Three species, Leptognathia armataHansen, , L. amdrupii Hansen, and L. hastata Hansen, are placed into this genus. Three new species, one from the Angola Basin, one from the deep sea of the tropical East Pacific and one from Antarctica are described. A key for the genus is provided.  相似文献   

14.
15.
《Journal of Natural History》2012,46(7):1125-1133
Two new genera of the bryozoan family Calloporidae are described from New Zealand. The first, Leptinatella, is introduced for L. gordoni n. sp., specimens of which have been referred in the past to Watersia militaris (Waters) but are distinct from this species, which is a phase of the cribrimorph Corbulipora tubulifera (Hincks). The second genus, Bryocalyx, is introduced for B. cinnameus n. sp., which has small, conical colonies anchored by rhizoids. Another species of Bryocalyx is known from a few fragments only: and has also been referred in the past to Watersia sp. It is briefly discussed, but left unnamed here.  相似文献   

16.
《Journal of Natural History》2012,46(6):1603-1610
The colony sizes and ovariole numbers of eight ponerine, one cerapachyine and one doryline species are reported. The ergatoid queens of five of these species are described briefly. Workers of the Hypoponera, Leptogenys and Anochetus species entirely lack ovaries, the first report of obligate sterility in this subfamily. Three evolutionary trends in the reproductive biology of the Poneriae are discussed: an increase in ovariole numbers and specialization for reproduction in the queen caste; worker sterility and increasing reproductive differentiation between the castes; and the evolutionary loss of specialization for dispersal in ergatoid queens.  相似文献   

17.
Two new species of rhagidiid mites are described from Oetztal Alps, Tyrol, Troglocheles archetypica n. sp. and T. aggerata n. sp. Their interspecific relationships are discussed and two new species-groups, T. strasseri and T. vornatscheri, are defined. A key to the known adult species of the genus Troglocheles Zacharda is given. Phylogenetic and evolutionary relationships among the known talus- and cave-dwelling species of this genus are briefly outlined, including the possibilities of sympatric versus allopatric speciation.  相似文献   

18.
19.
《Journal of Natural History》2012,46(24):2187-2201
A new species of the genus Pseudomonocelis (P. caribbea sp. n.) is described. It is distinguished from congenerics by shape and size of the copulatory organ and relative positions of mouth and genital openings. It is the first species of the genus found in America. Sampling in east Africa (Zanzibar island) revealed two species, attributed to P. pardii and, tentatively, to P. cavernicola, both originally described from Somaliland. Morphological differences between Tanzanian and Somali specimens are reported. The Mediterranean P. ophiocephala, based on extensive morphological and karyological survey of 13 populations, is interpreted as constituting at least two sibling species, distinguishable solely on the basis of karyotype. Results support the notion that the present perception of the contribution of interstitial Rhabditophora to marine biodiversity may be unrepresentative.  相似文献   

20.
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