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The inflorescences of Eleocharis elegans and Eleocharis sellowiana were investigated by dynamic headspace/GC–MS for the presence of volatiles. No floral volatile was detected in the inconspicuous inflorescences of E. sellowiana but various floral volatiles were produced by the showy inflorescences of E. elegans. The results are discussed in their ecological and evolutionary context.  相似文献   

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Abstract Here we use amplified fragment length polymorphism (AFLP) to assess genetic differentiation of Helicoverpa armigera and H. assulta . The results indicated that both species-specific fingerprints and cluster analysis showed the ability of AFLP technique to discriminate the two sibling species; among a total 1963 AFLP markers amplified from nine primer combinations: 777 (39.6%) were H. armigera -specific, 602 (30.7%) were H. assulta -specific, and 584 (29.7%) were common bands. The mean number of H. armigera -specific bands was significantly more than that of H. assulta -specific bands for nine primer combinations ( P < 0.05); the intraspecific distance of H. armigera and H. assulta was 0.123 0 and 0.110 7 respectively, and the interspecific distance was 0.178 3. In addition, the percentage of polymorphic loci and estimated average heterozygosity were used to estimate genetic diversity of the two species. This study therefore demonstrates that AFLP analysis is a sensitive and reliable technique to study genetic differentiation and genetic relationships between species and provides sufficient molecular markers for future linkage map construction, location and eventual cloning of genes involved in traits differentiation.  相似文献   

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D. W. Snow 《Ibis》2003,145(3):546-546
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Hymenopterans have become a model for the study of factors that govern sex allocation. In 1983, Seger proposed a model to study Sphecidae wasps with a strong prediction that sex ratio for univoltine wasps should be 1 : 1 (female : male), and for partially bivoltine species it should be male-biased. The present study investigates if Trypoxylon lactitarse (Saussure, 1867) is a univoltine or a bivoltine species and if Seger's model prediction fits the pattern of sex ratio found in this species. The study was carried out at Parque Municipal das Araucárias, in the municipality of Guarapuava, state of Paraná, southern Brazil, from December 2001 to December 2004. Nests of T. lactitarse were obtained using trap-nests drilled longitudinally to a depth to 80 mm with 7.0, 10.0 and 13.0 mm opening diameter. They were placed in a very heterogeneous site filled with araucaria forests, swamps and grasslands. Trypoxylon lactitarse showed two alternative life histories: either they pupated immediately and emerged as adults later in the same season (direct development), or they entered diapause, overwintering and pupating the following spring (delayed development). Its annual sex ratios were not significantly different from 1 : 1, and both sex ratio of overwintering and sex ratio of direct-developing wasps were also not significantly different from 1 : 1, in all years of this study. By examining these results, it was possible to conclude that although T. lactitarse is a multivoltine species, with four generations per year and two alternative life histories, its sex ratio did not support Seger's model.  相似文献   

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During a research project aimed at the study of the Culicinae fauna of Gabon and carried out in the National Park of La Lopé, we captured an unknown sandfly male specimen (genus Phlebotomus) by CDC miniature light trap belonging to a new species for Science. Furthermore, the originality of his genitalia does not allow us to include this species in one of the existing subgenus, thus in this paper we propose the creation of a new subgenus, as Phlebotomus (Legeromyia) multihamatus sp. nov., subg. nov. described from the National Park of La Lopé, through one male captured with CDC miniature light trap. A new species and a new subgenus of sandfly is characterised by a short style with three spines, a paramere wearing a basal hook as well as a basal pouch and the absence of basal lobe on the coxite. The originality of the genitalia of the male gives way to discussion about potential primary homologies between P. multihamatus sp. nov. and Phlebotomus (Abonnencius) fortunatarum, Phlebotomus (Anaphlebotomus) stantoni and Phlebotomus (Euphlebotomus) argentipes, which should be verified for future studies. The discovery of this new species in Gabon must encourage the study of sandflies in this country.  相似文献   

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A male infant is described with unusual facial appearance, clubfeet, and moderate hydrocephalus internus without obvious deficiency in mental and physical development. Cytogenetic studies revealed a karyotype of 45,XY,--C,--D,+t(C;D). A chromosome 11 and a 13 are involved in the formation of the translocation chromosome. The long arm of chromosome 13 is linearly attached to the end of the long arm of chromosome 11 (tandem translocation). Chromosome material of the distal part of the long arm of chromosome 11, as well as the short arm plus the centromere of chromosome 13 seem to have been lost.  相似文献   

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Long‐distance movements are characteristic of most seabirds in the order Procellariiformes. However, little is known about the migration and foraging ranges of many of the smaller species in this order, especially storm‐petrels (Hydrobatidae). We used Global Location Sensors to document the year‐round movements of sympatrically breeding Fork‐tailed Storm‐Petrels (Oceanodroma furcata) and Leach's Storm‐Petrels (O. leucorhoa) from the Gillam Islands located northwest of Vancouver Island, British Columbia, Canada. In 2016, breeding Fork‐tailed (= 5) and Leach's (= 2) storm‐petrels traveled maximum distances of ~1550–1600 km from their colony to a region that has a wide shelf with major canyons creating a highly productive foraging area. After the breeding season, Fork‐tailed Storm‐Petrels (= 2) traveled to similar areas west of the Gillam Islands, a maximum distance of ~3600 km from the breeding colony, and remained in the North Pacific Ocean and north of the Subarctic Boundary for an average of 5.4 mo. Post‐breeding Leach's Storm‐Petrels (= 2) moved south to the Eastern Tropical Pacific, west of central Mexico, Ecuador, and northern Peru, an estimated maximum distance of ~6700 km from their breeding colony, and remained there for an average of 7.2 mo. Carbon (δ13C) and nitrogen (δ15N) stable isotope analyses of feathers revealed niche separation between Fork‐tailed (= 21) and Leach's (= 53) storm‐petrels. The wide range of δ15N values in the feathers of Leach's Storm‐Petrels (= 53) suggests that they foraged at a variety of trophic levels during the non‐breeding season. Our results demonstrate that storm‐petrels have large core foraging areas and occupy vast oceanic areas in the Pacific during their annual cycle. However, given the coarse precision of Global Location Sensors, additional study is needed to identify the specific areas used by each species during both breeding and non‐breeding periods.  相似文献   

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The nematode Drilomermis leioderma n. gen., n. sp. (Merrnithidae) is described from larvae of Cybister fimbriolatus (Say) (Dytiscidae: Coleoptera) in Louisiana. Diagnostic characters of the genus Drilomermis are: medium-sized nematodes with the cuticle appearing smooth (lacking cross fibers) under the light microscope, six cephalic papillae, without mouth papillae, six hypodermal cords at midbody, 2 extremely long spicules (longer than 10 times body width at anus) which are separate and parallel (not twisted), an S-shaped vagina, medium-sized amphids located near head papillae, and postparasitic juvenile with a tail appendage. D. leioderma possesses a ventrally displaced mouth, very long vagina, and male genital papillae arranged in 3 double rows in the vicinity of the cloacal opening. Even when containing multiple parasites, about 40% of the hosts sulwived emergence of the memithids and lived several more days. In nature, some of these hosts may be able to continue their development, which is unusual since most mermithid-parasitized hosts die soon after the nematode emerges.  相似文献   

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The formation and structure of four different Cu(II)–clupeine Z complexes have been studied using potentiometric and spectroscopic (ir and visible absorption, and CD) measurements. The results thus obtained indicate the presence of up to 8 binding sites in the pH range from 6.5 to 10.5. The spectroscopic evidence suggests that the strongest site available contains the α-amino terminal and the adjacent peptide nitrogen, which bind to copper from pH 5 to 6.5 to form the first complex. The stability constant of this first complex has a value of (9.5 ± 0.9) × 103 mol?1 1. From pH 6.5 to 8.5, two intervening guanidinium nitrogens of arginine residues occupy the two other corners of the coordination square, giving rise to the second complex. The other sites potentially available from pH 6.5 to 10.5 are formed by two amino nitrogens of arginine residues and two contiguous peptide nitrogens. The first intervene up to pH 8.5, forming the third complex, and the latter from this pH to 10.5, forming the fourth complex. Although the ligands intervening at sites 2–8 appear to be the same, the sites are by no means equivalent. The spectroscopic data enable one to distinguish three different types of binding sites.  相似文献   

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