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171.
Easton R. White Halley E. Froehlich Jessica A. Gephart Richard S. Cottrell Trevor A. Branch Rahul Agrawal Bejarano Julia K. Baum 《Fish and Fisheries》2021,22(1):232-239
The US seafood sector is susceptible to shocks, both because of the seasonal nature of many of its domestic fisheries and its global position as a top importer and exporter of seafood. However, many data sets that could inform science and policy during an emerging event do not exist or are only released months or years later. Here, we synthesize multiple data sources from across the seafood supply chain, including unconventional real‐time data sets, to show the relative initial responses and indicators of recovery during the COVID‐19 pandemic. We synthesized news articles from January to September 2020 that reported effects of COVID‐19 on the US seafood sector, including processor closures, shortened fishing seasons and loss of revenue. Concerning production and distribution, we assessed past and present landings and trade data and found substantial declines in fresh seafood catches (?40%), imports (?37%) and exports (?43%) relative to the previous year, while frozen seafood products were generally less affected. Google search trends and seafood market foot traffic data suggest consumer demand for seafood from restaurants dropped by upwards of 70% during lockdowns, with recovery varying by state. However, these declines were partially offset by an increase (270%) in delivery and takeout service searches. Our synthesis of open‐access data sets and media reports shows widespread, but heterogeneous, ramifications of COVID‐19 across the seafood sector, implying that policymakers should focus support on states and sub‐sectors most affected by the pandemic: fishery‐dependent communities, processors, and fisheries and aquaculture that focus on fresh products. 相似文献
172.
173.
Dr. Bernard R. Baum 《Genetic Resources and Crop Evolution》1981,29(1):209-239
Summary The needs and aims of taxonomy of cultivated plants at the infraspecific level are dealt with briefly in the context of taxonomy in general. The components of infraspecific taxonomy of cultivated plants are formulated and defined. These components are: identification, classification, genealogy, nomenclature — that are complementary to each other. The desired requirements of each component are discussed in the light of a review, conducted for this paper, on the subject covering the period (1975-) 1976–1979.Developing automatic identification schemes for cultivars is becoming increasingly important. Identification needs to be accurate, rapid and devoid of human error. A classification system must be based on as many characters as possible and use numerical taxonomic techniques to generate and evaluate groupings. A suitable system would be composed of polythetic, non-hierarchical, informal groupings. The most useful genealogies are those that trace individual pedigrees as far back as possible. They can most profitably be done with the aid of computer systems, such as those used for oat and barley cultivars, by the author and his associates. Because there is no one to one correspondence between genealogies and classifications, pedigrees or genealogies enable one to draw inferences about cultivars different from those drawn from classifications. A nomenclature system for cultivars must be as complete as possible. This is achieved by listing all the cultivars names, commercial synonyms, translations and transliterations, and cross referencing. Examples of confusions due to faulty nomenclature are provided. In the author's opinion, a nomenclature system for cultivar groups is not needed because it is too cumbersome and because groups need not be formalized.It is desirable to work on the four components of infraspecific taxonomy at a world-wide basis to increase their usefulness for growers, merchants, breeders and scientists concerned with cultivar development and improvement. An exception might be in identification within a country whereby a local system might satisfy most current needs.
Taxonomie der infraspezifischen Variabilität von Kulturpflanzen
相似文献
174.
Thomas Krey Maria Caus Christel Baum Silke Ruppel Bettina Eichler‐Löbermann 《植物养料与土壤学杂志》2011,174(4):602-613
The organic matter supply can promote the dispersal and activity of applied plant growth–promoting rhizobacteria (PGPR), but the complementary effect of organic fertilization and PGPR application on the turnover of P is scarcely known. The effects of the application of two PGPR strains (Pseudomonas fluorescens strain DR54 and Enterobacter radicincitans sp. nov. strain DSM 16656) alone and in combination with organic fertilization (cattle manure and biowaste compost) on growth and P uptake of maize (Zea mays L.) and oilseed rape (Brassica napus L.) were investigated under semi–field conditions. Furthermore, P pools and phosphatase activities in soil and the arbuscular mycorrhizal colonization of maize were examined. The organic‐fertilizer amendments increased the growth and P uptake of both plant species and the soil P pools. The application of the E. radicincitans strain increased P uptake of oilseed rape when no organic fertilizer was added. Furthermore, the application of both bacterial strains increased the activities of phosphatases under both plant species. Here, the effect of the PGPR application even exceeded the effect of organic fertilization. The magnitude of this effect varied between the different fertilizing treatments and between the two bacterial strains. Phosphatase activities were increased to the greatest extent after application of P. fluorescens in the unfertilized soil. Under rape increases of 52% for acid phosphatase activities (ACP), 103% for alkaline phosphatase activities (ALP), and 133% for phosphodiesterase (PDE) were observed therewith. In the unfertilized soil, the application of P. fluorescens also resulted in a strong increase of the arbuscular mycorrhizal colonization of maize. We conclude that application of PGPR can promote the P mobilization and supply of crops in P‐deficient soils, however, in combination with organic fertilization these effects might be masked by a general improved P supply of the crops. Interactive effects of applied bacterial strains and organic fertilization depend on the sort of organic fertilizer and crop species used. 相似文献
175.
Jens Rohloff Else Berit Skagen Albert Håkon Steen Tor Beisvåg Tor-Henning Iversen 《Acta Agriculturae Scandinavica, Section B - Plant Soil Science》2013,63(3):161-168
Production of varieties of the medicinal plants Mentha 相似文献
176.
Species of Rafflesiaceae possess the world's largest flowers (up to 1 meter in diameter), yet their precise evolutionary relationships have been elusive, hindering our understanding of the evolution of their extraordinary reproductive morphology. We present results of phylogenetic analyses of mitochondrial, nuclear, and plastid data showing that Rafflesiaceae are derived from within Euphorbiaceae, the spurge family. Most euphorbs produce minute flowers, suggesting that the enormous flowers of Rafflesiaceae evolved from ancestors with tiny flowers. Given the inferred phylogeny, we estimate that there was a circa 79-fold increase in flower diameter on the stem lineage of Rafflesiaceae, making this one of the most dramatic cases of size evolution reported for eukaryotes. 相似文献
177.
Pierre Hellin Maxime Duvivier Aurélie Clinckemaillie Charlotte Bataille Anne Legrève Thies M. Heick Lise N. Jørgensen Björn Andersson Berit Samils Bernd Rodemann Gunilla Berg Steven Kildea 《Plant pathology》2020,69(9):1666-1677
Demethylation inhibitor (DMI) and succinate dehydrogenase inhibitor (SDHI) fungicides are currently relied upon for the control of septoria tritici blotch (STB) in European wheat fields. However, multiple mutations have occurred over time in the genes encoding the targeted proteins that have led to a practical loss of fungicide efficacies. Among the different amino acid substitutions in Zymoseptoria tritici associated with resistance to these fungicides, S524T in CYP51 (DMI target) and H152R in SdhC (SDHI target) are regarded as conferring the highest resistance factors to DMI and SDHI, respectively. To facilitate further studies on the monitoring and selection of these substitutions in Z. tritici populations, a multiplex allele-specific quantitative PCR (qPCR) assay allowing for estimation of both allele frequencies in bulk DNA matrices was developed. The assay was then used on complex DNA samples originating from a spore trap network set up in Belgium, Denmark, Sweden, and Ireland in 2017 and 2018, as well as on leaf samples with symptoms. The S524T allele was present in all field samples and its proportion was significantly higher in Ireland than in Belgium, whereas the proportion of H152R was only sporadically present in both countries. The frequency of S524T varied greatly in the airborne inoculum of all four countries; however, the H152R allele was never detected in the airborne inoculum. The method developed in this study can be readily adopted by other laboratories and used for multiple applications including resistance monitoring in field populations of Z. tritici. 相似文献
178.
Ecological correlates of RAPD DNA diversity of wild barley, Hordeum spontaneum, in the Fertile Crescent 总被引:4,自引:0,他引:4
Eviatar Nevo Bernard Baum Avigdor Beiles Douglas A. Johnson 《Genetic Resources and Crop Evolution》1998,45(2):151-159
Genetic variability in RAPDs (Randomly Amplified Polymorphic DNA) was studied in 104 genotypes of wild barley, Hordeum spontaneum from 21 populations sampled in Israel, Turkey and Iran, seven population from each country. The band (= loci) frequencies were calculated for each population and correlated with ecogeographical variables. In general, high RAPD genetic diversity indices were associated with stressful environments, either with hot or cold steppes and deserts. Interpopulational genetic distances showed no association with the geographic distance between the populations' provenance. Significant Spearman rank correlations between RAPD band frequencies and ecogeographical parameters of provenance occured. Frequencies of RAPD bands were significantly correlated with the principal component factors of allozymes. The correlation data indirectly suggest that natural selection appears to be the major determinant of both RAPD and allozyme diversities both being correlated with environmental stress. 相似文献
179.
180.
Jay V. Huner Vernon A. Pfister Robert P. Romaire Tammy J. Baum 《Journal of the World Aquaculture Society》1990,21(4):288-294
In the USA, cambarid crawfishes are harvested commercially with traps baited with fishes, formulated baits, or a combination of the two. Commercially formulated baits and fish baits, done and in combination, were evaluated to assess their relative effectiveness M attractants for crawfish. Traps baited with a combination of fish and formulated bait generally captured the most crawfish. Traps baited with common carp, the most effective natural bait, captured more crawfish than traps baited with skipjack herring, gizzard shad or channel catfish heads. Crawfish harvest from traps baited with several types of commercially formulated baits was equal to that obtained with traps baited with either gizzard shad or skipjack herring. Population density of crawfish and the availability of natural forage did not appear to influence relative effectiveness of either formulated baits or fish baits. 相似文献