Search results for "TIP"
showing 10 items of 6351 documents
Two new varieties in Stipa (Poaceae) from Central Asia
2016
Abstract The paper presents descriptions of two new taxa, Stipa ×brevicallosa var. hissarensis and Stipa orientalis var. ladakhorum. Both of them differ from the nominal varieties in having densely pubescent (not glabrous or scabrous) leaves of vegetative shoots. First of the above mentioned taxa occurs in Tajikistan (Pamir Alai Mts) whereas the second in India (Western Himalayas). Images of type specimens of both taxa are provided.
Influence des phosphates naturels et des mycorhizes à vésicules et à arbuscules sur la croissance et la nutrition minérale de Zizyphus mauritiana Lam…
1998
Rock phosphate and vesicular-arbuscular mycorrhiza effects on growth and mineral nutrition of Zizyphus mauritiana Lam. in an alkaline soil. The influence of vesicular-arbuscular mycorrhizae (VAM) and rock phosphate (RP) was studied on jujube (Zizyphus mauritiana Lam.), a multipurpose fruit tree in Sahelian agroforestry systems. Jujubes were inoculated or not by Clomus manihotis Howeler, Sieverding & Schenck in an alkaline sandy soil to which were added five levels of RP (12 % of P) : 0.00, 0.31, 0.62, 1.25 et 2.50 g P/kg of soil, equivalent to 0, 775, 1 550, 3 125 et 6 250 kg P ha -1 . The jujubes seedlings grew poorly without mycorrhizal colonization and without RP applications (figures 1a…
Food stoichiometry affects the outcome of Daphnia–parasite interaction
2013
Phosphorus (P) is an essential nutrient for growth in consumers. P-limitation and parasite infection comprise one of the most common stressor pairs consumers confront in nature. We conducted a life-table study using a Daphnia–microsporidian parasite model, feeding uninfected or infected Daphnia with either P-sufficient or P-limited algae, and assessed the impact of the two stressors on life-history traits of the host. Both infection and P-limitation negatively affected some life-history traits tested. However, under P-limitation, infected animals had higher juvenile growth rate as compared with uninfected animals. All P-limited individuals died before maturation, regardless of infection. Th…
A manipulative parasite increasing an antipredator response decreases its vulnerability to a nonhost predator.
2009
8 pages; International audience; Trophically transmitted parasites have to deal with the antipredator adaptations of their intermediate hosts. Some of these parasites induce behavioural changes in their intermediate hosts that make them more vulnerable to predation by definitive hosts. However, the adaptiveness of behavioural manipulation also depends on the probability of being eaten by a nonhost predator. Parasites might therefore try to use specific antipredator responses of intermediate hosts to avoid this dead end. We tested this hypothesis using the acanthocephalan Polymorphus minutus and its intermediate amphipod host, Gammarus roeseli. In their natural habitat, uninfected G. roeseli…
Stipa dickorei sp. nov. (Poaceae), three new records and a checklist of feather grasses of China
2016
Stipa dickorei sp. nov. from the Western Tibetan Plateau (China) is described. The new species is morphologically similar to S. regeliana, but they differ from each other in the length of ligules of vegetative shoots. Stipa dickorei is also similar to S. aliena, however they differ in the shape of panicle, which is contracted with straight branches in S. dickorei, and lax with flexuous branches in S. aliena. Images of macromorphological and micromorphological structures of the new taxon are provided. Additionally, new records of S. borysthenica, S. richteriana, and S. zalesskii, species not listed in the recent Flora of China, as well as a checklist of Chinese feather grasses are also prese…
Opinions 100, 101 and 102
2020
The International Committee on Systematics of Prokaryotes has formally made final decisions, taking into account the conclusions of the Judicial Commission, on three pending Requests for an Opinion, thereby allowing the corresponding Opinions to be issued. According to Opinion 100, the request for the recognition of strain A1-86 (=DSM 17629=NCIMB 14373) as the neotype strain of Eubacterium rectale (Hauduroy et al. 1937) Prévot 1938 (Approved Lists 1980) is denied, ruling that a neotype does not need to be designated for E. rectale because strain VPI 0990 (=ATCC 33656=CIP 105953) is considered to be a duplicate isolate of the same strain as VPI 0989 (=ATCC 25578) and may serve as its nomencl…
Iridescent structurally based coloration of eyespots correlates with mating success in the peacock.
2007
Gaudy plumage coloration is a widespread ornamental trait in birds and thought to be sexually selected. Although much attention has been devoted to structural coloration reflecting in UV, the signaling function of structural colors lacking UV reflectance and those that exhibit iridescence coloration are poorly documented. The train of the peacock (Pavo cristatus), a classical example of a sexually selected trait, is composed of iridescent structurally colored eyespots not reflecting in UV. Until today, the role played by the structural color of the eyespots in female mate choice has never been investigated using spectrometry. We measured eyespot coloration from a stationary angle (static co…
An invasive insect herbivore disrupts plant volatile-mediated tritrophic signalling
2017
Plants respond to insect attack by emission of volatile organic compounds, which recruit natural enemies of the attacking herbivore, constituting an indirect plant defence strategy. In this context, the egg parasitoid Trissolcus basalis is attracted by oviposition-induced plant volatiles emitted by Vicia faba plants as a consequence of feeding and oviposition by the pentatomid host Nezara viridula. However, this local tritrophic web could be affected by the recent invasion by the alien pentatomid bug Halyomorpha halys, an herbivore that shares the same environments as native pentatomid pests. Therefore, we investigated in laboratory conditions the possible impact of H. halys on the plant vo…
Eutrophic status influences the impact of pesticide mixtures and predation on Daphnia pulex populations
2021
Abstract Pesticides, nutrients, and ecological stressors such as competition or predation co‐occur in freshwater ecosystems impacted by agriculture. The extent to which combinations of these stressors affect aquatic populations and the role of nutrients availability in modulating these responses requires further understanding. In this study, we assessed how pesticides affecting different taxonomic groups and predation influence the response of Daphnia pulex populations under different trophic conditions. An outdoor experiment was designed following a factorial design, with the insecticide chlorpyrifos, the herbicide diuron, and the predation by Notonecta sp. individuals as key stressors. Th…
Multivariate morphometric analysis of the Stipa turkestanica group (Poaceae: Stipa sect. Stipa)
2015
Based on numerical analyses of macromorphological characters (cluster analysis, principal coordinate analysis and principal component analysis), scanning electron microscopy observation of lemma and lamina micromorphology, as well as field observations, five taxa belonging to the Stipa turkestanica group have been recognized in the mountain area of Central Asia. They are S. turkestanica subsp. turkestanica, S. turkestanica subsp. trichoides, S. macroglossa subsp. macroglossa, S. macroglossa subsp. kazachstanica and S. kirghisorum. As a result of this study, we propose one new combination, S. macroglossa var. pubescens, and designate lectotypes for S. turkestanica subsp. trichoides and S. ma…