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11.
Nazgol Emrani Mario Hasler Dilan S. R. Patiranage Maldonado-Taipe Nathaly Elodie Rey Christian Jung 《Plant Breeding》2020,139(6):1190-1200
Quinoa offers a promising alternative for staple food, considering its outstanding nutritional value and tolerance to abiotic stresses. To develop breeding programmes in quinoa, a reliable crossing method for increasing the genetic variation is required. In the following study, we aimed to develop segregating populations in quinoa. We tested the efficiency of three different crossing methods (hand emasculation, warm water emasculation and no emasculation). Moreover we developed a two-stage selection strategy based on morphological traits and molecular markers for the selection of hybrid plants. We reported hand emasculation to be the most efficient crossing method, followed by warm water emasculation and no emasculation. Our results demonstrated that crosses in quinoa can be successfully performed, despite its complicated flower structure and high self-pollination rate. Additionally, we developed 30 segregating populations from crosses between accessions of different origins with varying phylogenetic relationship, which offers a promising perspective for quinoa breeding programmes in the future. 相似文献
12.
Atmospheric new particle formation enhanced by organic acids 总被引:4,自引:0,他引:4
Zhang R Suh I Zhao J Zhang D Fortner EC Tie X Molina LT Molina MJ 《Science (New York, N.Y.)》2004,304(5676):1487-1490
Atmospheric aerosols often contain a substantial fraction of organic matter, but the role of organic compounds in new nanometer-sized particle formation is highly uncertain. Laboratory experiments show that nucleation of sulfuric acid is considerably enhanced in the presence of aromatic acids. Theoretical calculations identify the formation of an unusually stable aromatic acid-sulfuric acid complex, which likely leads to a reduced nucleation barrier. The results imply that the interaction between organic and sulfuric acids promotes efficient formation of organic and sulfate aerosols in the polluted atmosphere because of emissions from burning of fossil fuels, which strongly affect human health and global climate. 相似文献
13.
Catherine Taverny Isabelle Ortusi Charles Roqueplo Mario Lepage Patrick Lambert 《Ecology of Freshwater Fish》2012,21(1):87-99
Abstract – Habitat requirements of lamprey ammocoetes (Petromyzon marinus and Lampetra genus) were investigated, for the first time, from shallow to deep waters, at different spatial scales across the Gironde‐Dordogne continuum, thanks to a water suction dredge. Fish‐habitat relationships were assessed through two complementary statistical analyses: habitat‐use curves and habitat suitability models using the Boosted Regression Trees (BRT) technique. Analyses were performed on a small‐size data set that was characterised by the low prevalence of lamprey. The sea lamprey larvae occurred in deeper areas than their Lampetra genus counterparts. ‘Pools’ of 2 m’ depth and more were optimal habitats for the former species. Among the environmental variables retained to model lamprey occurrences, the mesohabitat (a categorical variable) was demonstrated to be highly influential, in terms of fine grain‐size substratum and vegetation cover. These preliminary results suggest that monitoring using the water suction dredge method may contribute to sea lamprey conservation. 相似文献
14.
Chiara B. Vicentini Vincenzo Brandolini Tiziana Poli Mario Guarneri Paolo Giori 《Pest management science》1992,34(2):127-131
3-Methyl-5-(acyl/alkyl)aminoisoxazole-4-thiocyanates were prepared by rhodanation of N-acyl/alkyl-3-methyl-5-isoxazolamines. These products were tested for antifungal activity against a series of phytopathogenic fungi of different taxonomic classes. Some of the compounds showed interesting in-vitro activity. The more active compound in the in-vitro test displayed a moderate preventive activity against Plasmopara viticola, Alternaria solani and Pyricularia recondita. 相似文献
15.
Irene Abbattista Gentile Lucia Ferraris Mario Sanguinetti Marinela Tiprigan Giuseppina Fisichella 《Pest management science》1992,34(3):297-301
The effect of some physical factors on the processes (hydrolysis, volatilisation) regulating the persistence of methyl bromide in fresh surface waters was investigated to complement previous research. It has been confirmed that electromagnetic radiation in the visible field has no influence on the hydrolysis kinetics of the fumigant. The removal of methyl bromide by volatilisation from stirred and ventilated solutions appears to be of greater importance in practice. It has been shown that under these conditions the half-life is directly proportional to the liquid depth. Without stirring volatilisation is greatly reduced, due to the low diffusivity of methyl bromide in the aqueous phase. 相似文献
16.
Villarino MA Garcia O Fussell W Preston K Wagner GG 《Preventive veterinary medicine》2003,61(4):333-338
After the civil war and the Hurricane-Mitch disaster, cattlemen in Nicaragua were forced to transport their cattle from lowland areas to higher, dryer areas of the country. These areas are natural ecological niches for the cattle grub Dermatobia hominis (L. Jr.) (Diptera: Cuterebridae). To determine the importance of this infestation, the Agricultural and Livestock-Forestry Ministry selected a central area of Nicaragua to run a pioneer survey program to acquire information about hosts involved, number of cases, treatments applied and general knowledge of 42 farmers about the life cycle of the parasite. The subjects were either farm owners or farm managers. Ninety-five percentage of the farms indicated cases of D. hominis infestation in their animals, with cattle being the most affected host (100% of the affected farms). There was poor understanding of the D. hominis life cycle, vectors and control methods. A misuse of insecticides for the treatment of larval infestation by D. hominis was indicated. 相似文献
17.
18.
The forests of Austrocedrus chilensis in southern Argentina suffer mortality from “mal del ciprés”, whose causes remain unknown. The purpose of this work was to establish the relation of soil features with the occurrence of the disease. In Río Grande Valley, Chubut Province, Argentina, 14 areas with “mal del ciprés” were selected for study. The spatial pattern of the decline varied among the different areas and was classified as aggregated and disaggregated. In each area, symptomatic and asymptomatic plots were established and characterized by 11 edaphic and topographic variables. Three forest areas where the disease was totally absent were also included. Site features were related to the occurrence of the decline using principal component analysis and cluster analysis. Results indicated that soil properties related to poor internal drainage, such as the proximity to water streams, non-allophanized soils of fine textures, and redoximorphic features, act as predisposing factors to the development of “mal del ciprés”. Poor soil drainage was strongly associated not only with the occurrence of the disease, but also with its spatial pattern. Symptomatic and asymptomatic plots presented similar edaphic features in areas with a disaggregated distribution of the decline and were grouped together in the multivariate analysis. This result suggests that large areas with such a pattern are prone to develop the decline. 相似文献
19.
This study focuses on the problem of irregular diameter structure in a silver fir–beech selection (plenter) forest with a “surplus” of large diameter trees and a lack of natural regeneration and small diameter trees. We sampled 274 plots (900 m2 each) in the Belevine research site (266.24 ha) in the mountain region Gorski Kotar (Croatia), where diameter (dbh) distribution, diameter increment, and natural regeneration were analyzed in detail. A low density of natural regeneration, weak annual recruitment of small (10 cm dbh) diameter trees (only five trees per hectare), delayed diameter growth of trees, and a low annual rate of trees reaching the next dbh class were attributed to the current irregular dbh structure. The stand development prediction for the next 50 years is based on a simulation model, which considers the current diameter structure, increment, recruitment, and future cutting regime. Intensive cutting in the first of five 10-year cutting cycles (intensity higher of 25%) is needed to initiate natural regeneration and to accelerate growth of young silver fir trees. In the next 50 years, the irregular diameter structure will be gradually improved. 相似文献
20.