Search results for " taxonomy."

Keragaman Jenis Tanaman Pada Dua Sistem Pertanian di Pegunungan Arfak Papua Barat

2021

The geographical of Pegunungan Arfak Regency was at 1200 - 2300 meters above sea level, has a mountainous topography, potential for the development of economic highlands crops. The aim this research was to see the diversity of cultivated plant by Arfak people at Arfak mountainous in their field and yard farming system. These studies were conducted at 2 Districts: 1) Anggi: Testega, Bamaha and Kostera Village; 2) Anggi Gida at Tuabiam Village of  Pegunungan Arfak Regency. The data collected by survey technique. The results showed there were a diversity of cultivated plants at two different farming system by Arfak people. There were 30 cultivated plants in four villages; consisted of 9 types …

The Taxonomy Lab: a lookout in the Mediterranean Sea

2016

Une chrysomèle contre l'ambroisie, est-ce réaliste ?

2016

Context - Despite intensive management practices carried out by stakeholders, common ragweed control is presently not sufficient to limit the spread of this annual invasive plant. Ali classical methods (mowing, chemical weeding, etc.) are limited in terms of efficiency. ln order to achieve a better management in the different habitats occupied by the plant, it is necessary to design innovative methods that could increase contra efficiency. The recent accidental introduction of a ragweed natural enemy in ltalia raises the question of the use of biological control agents. Could the regulation by a new phytophagous insect be considered as an integrated way of management in order to reduce the …

Permineralized coniferophytes from the Autun Basin: specimens from two new localities of Renault zone 3

2015

International audience; Four zones yielding silicified plant remains have been recognized in the Autun Basin by Renault (1893-1896). Zones 2, 3 and 4, characterized by Autunian plants, correspond to the successive formations of Igornay and Muse (lower Autunian), and Surmoulin-Millery (upper Autunian). Their paleobotanical content, together with that preserved as adpressions in the same formations, document paleofloral changes on the western side of the Tethys within a time interval extending from the latest Ghzelian (uppermost Pennsylvanian) to the early Sakmarian (lower Permian) (Broutin et al. 1999). The analyses realized so far indicate a progressive replacement of wetland plants by taxa…

La lutte biologique contre l'ambroisie à feuille d'armoise illustrée par l'exemple d'Ophraella communa : quels intérêts et quelles limites

2016

Common ragweed (Ambrosia artemisiifolia) was introduced in France over 150 years ago and its spreading across France now seems inexorable. The specific biology of this summer annual creates new problems for the managers of the various habitats where the plant can be found. The reduced possibility, or even the impossibility, to use traditional control means in certain environment conditions brings managers to consider biological control as one of the few possible means for slowing down the spread, or even pushing back the distribution area, of this invasive and allergenic plant. With Ophraella communa as an example, a reflection is presented on the benefit-risk balance of the introduction of…

Genetic Diversity of Rhizobia Isolated from the Legume Genera Astragalus, Oxytropis and Onobrychis

1998

The legume genera Astragalus and Oxytropis belong to the tribe Galegae. These legumes are common in Arctic and Temperate climatic zones. Previous studies based on cross-inoculation experiments and numerical taxonomy (Prevost et al., 1987; Novikova et al., 1993; 1994) suggested that the rhizobia associated with these legumes were closely related. Also the legume species Onobrychis viciifolia (sainfoin, tribe Hedysareae) was effectively nodulated by rhizobia isolated from Astragalus and Oxytropis spp. (Prevost et al., 1987). Rhizobia isolated from A. sinicus were classified in a new species, Mesorhizobium huakuii, (Chen et al., 1991; Jarvis et al., 1997). Other rhizobia from Astragalus and Ox…

Les Gonorynchiformes fossiles : distribution et diversité.

2007

8 pages; Longtemps placés dans les clupéiformes, les Gonorynchiformes ont rejoint les Ostariophysi au sein desquels ils représentent le groupe-frère des Otophysi. La monophylie du groupe est maintenant bien établie tant par les données morphologiques que moléculaires. De nos jours, quatre familles sont représentées par sept genres (dont cinq d'eau douce) et 35 espèces (dont 28 d'eau douce). Les Gonorynchiformes fossiles sont connus depuis le Crétacé basal (soit 145-140 millions d'années) jusqu'au Miocène basal (soit 23,5-20 millions d'années), et plusieurs taxons ont de grandes extensions temporelles. Ils sont représentés par environ 18 genres et 34 espèces. Avec moins de 50 localités fossi…

Crustacés amphipodes de surface (Gammares d'eau douce)

2012

EA MERS CT3; National audience; L’ouvrage de Piscart & Bollache présente une clef de détermination actualisée des amphipodes de surface de la France métropolitaine. Les espèces natives et invasives sont décrites, avec une carte de la répartition de chaque espèce. L’ouvrage est agrémenté d’une partie décrivant l’écologie des amphipodes, leur comportement et leurs pathogènes les plus fréquemment rencontrés.

Copper binding capacity of root exudates of cultivated plants and associated weeds

2001

International audience; Cu binding to root exudates of two cultivated plants, wheat (Triticum aestivum) and rape (Brassica napus), and two weeds associated with wheat, dog daisy (Matricaria inodora) and cornflower (Centaurea cyanus), was studied in vitro under hydroponic and sterile conditions. Nutrient solutions were prepared with or without P. A MetPLATE microbiological test was used to assess the metal complexing capacity of root exudates. In the P-deficient solutions, no exudation was observed for any of the four plants; consequently, no Cu binding occurred. When P was present in the nutrient solutions, the plant exudates displayed differing abilities to complex Cu. No difference was de…

Thilachium madagascariense (Capparaceae), a new species from eastern Madagascar with a key to the species of the genus

2021

SummaryThilachium madagascariense Fici, a small tree characterised by 1-foliolate leaves with articulate petioles, leaf blades elliptic or narrowly obovate with base attenuate and apex acuminate, flowers in groups of 2 – 3 at the top of lateral twigs and a high number of stamens, is described and illustrated from forest habitats of eastern Madagascar. The new species is similar to T. laurifolium Baker, a species endemic to central and eastern Madagascar, differing in the longer leaves with acuminate apex, flowers conferted at the top of lateral twigs, shorter pedicels, higher number of stamens and shorter gynophore. Its affinities are discussed and an updated key is provided for all the spe…