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991.
Inocêncio de Sousa Gorayeb 《ZooKeys》2014,(395):23-31
Elephantotus, a new genus of Tabanidae from the Amazon coast, Brazil, is described based on a new species E. tracuateuensis. Five females were collected in Pará State, and a male in Maranhão State. Arguments are presented for separating the new genus from Dasybasis, as well as the possibility of its occurrence being related to the nesting sites of coastal birds. The new species is characterized by its large size (x = 2.15 cm, n = 5 females), glabrous eyes, reddish-brown tegument, light brown frontal callus not touching the edges of the eyes, extending up to the vertex that has traces of ocelli, basal plate of the antennal flagellum with obtuse angle, without a tooth or spine, wings hyaline, with brown basal cells, without appendix in the fork of vein R4+5, and genital furca wide with extended flaps. 相似文献
992.
993.
Yoshinobu Hoashi 《Mycoscience》2008,49(6):385-387
Psathyrella turcosomarginata is described and illustrated as a new species from Japan (Fukuoka Prefecture, Kyushu). This species is assigned to section
Spintrigerae because of its lack of pleurocystidia and basidiome habit. It is characterized by having fairly large basidiomes, a distinct
sulcate-striate pileal margin, and cheilocystidia with mucoid deposits that stain bluish green in ammonia solution. 相似文献
994.
Anton Weber 《Plant Systematics and Evolution》1987,157(3-4):187-199
Phyllagathis tuberculata
King and two closely allied new species,P. magnifica
A. Weber andP. stonei
A. Weber, are described and illustrated. Within the genus, these species form a distinct and isolated group which is restricted to Peninsular Malaysia.P. tuberculata occurs in Perak (probably confined to G. Bujang Melaka),P. magnifica andP. stonei are found in the mountains on the Pahang/Selangor border (Genting Highlands, Gombak valley). The distinctive characters of the three species are listed and some general information relating to inflorescence morphology, tubercle anatomy, fruit structure and seed dispersal is provided. 相似文献
995.
996.
From the study of plant hemoglobin protein and gene sequences, a consensus sequence was constructed and analysed by computer
methods; analysis comprised the amino acid composition, hydropathy profile, and match degree with other plant and non-plant
hemoglobin sequences. Resulting consensus sequence shows the main features of hemoglobin genes and proteins in plants. 相似文献
997.
Abstract. Due to the complexity of coastal barrier vegetation, it is useful to apply a functional-type approach to assess the response of barrier island vegetation to climate change. In this paper, a simple clustering analysis is applied to a group of 19 plant associations, based on six plant attributes and six environmental constraints. This analysis results in the suggestion that the main division of the vegetation types at Virginia Coast Reserve is between herbaceous and woody types, which differs from the existing classification which recognizes three groups: xeric-mesic herbaceous, woody and hydric-halophytic herbaceous. Considerations about grouping plant functional types are also addressed in this paper. At a global scale, inclusion of barrier plant functional types may not be so important for the climate-change response of vegetation, but it may be necessary to consider these important systems for spatially explicit modelling of landscape responses. 相似文献
998.
We determined the relationship between plant height and whole-plant relative growth rate (g g-1 day-1) for ten genotypes of Sporobolus kentrophyllus collected from an intensively grazed site on the Serengeti Plains, Tanzania. Plants were grown for 7 weeks in a greenhouse in Syracuse, N.Y., and harvested weekly. Plants that received simulated bovine urine showed a negative relationship between plant height and growth rate, suggesting a genetic tradeoff between competitive ability if ungrazed (height) and ability to recover from grazing (growth rate). There was no height-growth rate relationship under nitrogen addition rates similar to field mineralization rates. In addition, faster-growing, shorter plants tended to have relatively higher above-ground growth rates than slower-growing, taller plants. These results suggest that natural selection has maintained a gradient of morphologies within this species ranging from short, rapidly growing genotypes adapted to intense grazing conditions to tall, slow-growing, grazer-susceptible genotypes that are superior light competitors in absence of herbivory. 相似文献
999.
《Geobios》2014,47(1-2):31-38
A new calcareous nannofossil, Crepidolithus cantabriensis nov. sp., is described from the Lower Jurassic marls and marly limestones of the Cantabrian Range (Northern Spain). The new species is characterized by medium-sized, normal to narrowly elliptical coccoliths with open central-areas. In the light microscope, under crossed nicols and in distal view, it displays a characteristic bicyclic extinction pattern. Its inner rim edge shows maximum birefringence colours, which vary from white to yellow, whereas the faintly outer rim margin exhibits low birefringence, tending to grey, and they are separated by a dark and sigmoidal isogyre. C. cantabriensis nov. sp. seems closely related to Crepidolithus crassus on the basis of shared morphological characters. Both of them have a distal shield composed of around thirty sub-vertical, dextrally imbricating laths. The central-area width of C. cantabriensis nov. sp. is approximately half of the coccolith width, whilst it is reduced to one or two tiny lenticular slits in C. crassus. Nevertheless, the phyletic relationships between C. cantabriensis nov. sp. and Crepidolithus cavus are not clear, since they show different rim structures, and C. cavus has a delicate bar aligned along the minor axis of its central area. The first specimens of C. cantabriensis nov. sp. have been recognized within the Raricostatum AZ in the Tudanca section. This species seems to be more abundant in the Reinosa area, which occupied a more distal position with respect to the Iberian Massif during the studied time interval. It is hypothesized here that C. cantabriensis nov. sp. could have inhabited the lower-photic zone. 相似文献
1000.
T. J. Orton 《Plant Cell, Tissue and Organ Culture》1985,4(2):159-169
Genetically marked tissues of celery (Apium graveolens) were employed to contrast genetic and chromosomal stability in serially bulk-transferred callus and regenerated plants. After six months in culture, 84% of the callus cells were karologically indistinguishable from normal, while the remainder exhibited chromosome loss and/or fusion. All of 50 clones derived from this tissue expressed the control phenotype with respect to heterozygous isozyme markers. Of 95 plants regenerated from the same tissue, 94 were phenotypically indistinguishable from the original explant donor, and cytogenetic analyses revealed the presence in 4.3% of an accessory chromosome, while the remainder were normal diploids. Analysis of the selfed progeny of these regenerated plants revealed the presence of a new recessive mutation causing abnormal leaf morphology at a frequency of 1.8%. Only one of 40 cells in 12-month-old callus tissue was karyologically indistinguishable from normal, the remainder consisting primarily of hypodiploids. The observation that all 50 clones were phenotypically heterozygous was statistically inconsistent with the hypothesis that hypodiploidy was associated with random complete chromosome loss. The culture had, at this point, lost the ability to regenerate. It is speculated that embryogenic cloning of celery may be suitable under certain circumstances for direct field establishment, but that levels of new genetic variation are sufficiently high to preclude its use for seed production. 相似文献