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排序方式: 共有1343条查询结果,搜索用时 15 毫秒
1.
Renan C. Lima Pablo H. Teixeira Ari F. F. Souza Trazilbo J. Paula Júnior Hudson Teixeira Miller S. Lehner José E. S. Carneiro Tiago S. Marçal Rogerio F. Vieira 《Plant pathology》2020,69(6):1172-1184
Development of common bean cultivars with partial white mould resistance through breeding techniques has been a challenge in Brazil. As yet, lines/cultivars from breeding programmes have not been investigated for resistance; therefore, this study screened 107 lines/cultivars for their reactions to white mould in 14 preliminary trials conducted under irrigation. Thirteen resistant lines/cultivars (three of Andean origin) and six Mesoamerican cultivars (three intermediately resistant and three susceptible) were selected for further investigation. These lines/cultivars and the resistant control A195 were evaluated in six advanced trials and two straw tests to assess the effectiveness of the screening procedure. In 11 preliminary trials, screenings were performed under moderate/high or higher disease pressure. These pressures occurred in two advanced trials in which, when yields were averaged across moderate/high and high pressures, 10 Mesoamerican lines/cultivars selected for resistance yielded 14%, 23%, and 38% more than intermediately resistant cultivars, A195, and susceptible cultivars, with median disease ratings (1–9 scale) of 4.5, 5.7, 5.7, and 6.7, respectively. In the straw test, three Andean lines/cultivars (A195 included) and two susceptible cultivars in the field were among those with the highest levels of physiological resistance. Thus, field rating under high disease pressure and greenhouse rating did not correlate significantly, suggesting that field trials are critical to evaluating resistance and to identifying high-yielding beans. Therefore, lines/cultivars from breeding programmes assessed in field trials may provide a low cost and fast way to identify high-yielding bean cultivars with partial resistance to white mould in the subtropical southern hemisphere. 相似文献
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Johnson Shelby L. Park Hyun Y. Vattem Dhiraj A. Grammas Paula Ma Hang Seeram Navindra P. 《Plant foods for human nutrition (Dordrecht, Netherlands)》2020,75(4):512-517
Plant Foods for Human Nutrition - Emerging data support that plant food based isoflavones have ameliorating effects on a variety of neurodegenerative diseases including Parkinson’s disease... 相似文献
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This paper empirically examines the key factors driving UK direct investment in the Spanish regions over the period 2000–2016 and, consequently, tries to unveil its main motivation. Applying a spatial Durbin panel model to capture spatial linkages, the results point to the existence of complementarity between the FDI received by a region and that of the remaining ones. This outcome, along with a positive and statistically significant spillover effect of market potential, reveals that complex-vertical FDI motivation with agglomeration economies prevails among UK MNEs investing in Spain. Additionally, our findings unveil the role played by some other FDI drivers, such as wages and infrastructure. Furthermore, the paper is unique in decomposing the average direct and spillover effects by region and pairs of regions, so that remarkable differences can be identified. This breakdown has strong significance from a policy perspective since it can guide regional policy makers. In short, our findings point out to the fact that FDI policy should be jointly designed by those regions presenting strong bilateral spillover effects. Thus, greater cooperation among policy makers would be welcome. 相似文献
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Effects of different variable sets on the potential distribution of fish species in the Amazon Basin
Facundo Alvarez Pedro Gerhard Daniel Paiva Silva Bruno Spacek Godoy Luciano Fogaça de Assis Montag 《Ecology of Freshwater Fish》2020,29(4):764-778
Estimating species’ potential distribution is one of the main objectives of macroecology, especially when sampling biases can affect knowledge on how environmental variables affect species distribution. Ecological niche models estimate species’ environmental niches from different variables and their occurrences. Using the presence-only data from eight Amazonian fish species, which inhabit rivers and streams, we aimed to (a) explore the effect of different sets variables on the spatial distributions of target species and (b) evaluate the predictive responses of MaxEnt to sets of variables with different degrees of complexity. MaxEnt has high flexibility in relation to the input data and its performance is influenced by a moderate number of adjustable parameters, allowing for high precision results when balancing underestimation and overestimation errors. We used environmental predictors in MaxEnt the principal components of climatic, topographic and edaphic variables as inputs. The combination of topographic and edaphic variables produced more precise and spatially restricted distribution ranges for all species when compared to those generated with climatic variables. All models reached high AUC values, especially for stream species. Modelled range sizes were broader for the river species, suggesting different tolerance thresholds and habitat preferences when compared to stream species. The complexity of the different variables sets did not affect MaxEnt's prediction capacity. However, for stream species, MaxEnt showed a greater predictive power. This work increases the knowledge with regards to the influence of different environmental predictors on the spatial patterns of the distribution of Amazonian fish. 相似文献
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Broodstock conditioning of the Portuguese oyster (Crassostrea angulata,Lamarck, 1819): influence of different diets 下载免费PDF全文
Catarina Anjos Teresa Baptista Sandra Joaquim Susana Mendes Ana Margarete Matias Paula Moura Tiago Simões Domitília Matias 《Aquaculture Research》2017,48(7):3859-3878
The Portuguese oyster Crassostrea angulata shows great potential in oyster farming. The conservation of pure populations of this species is important for production diversification and biodiversity preservation. In this way, the zootechnological development for seed hatchery production is extremely important. Broodstock conditioning is a key step in the process of rearing bivalves in a hatchery. Many factors regulate the reproductive cycle, being food one of the most important ones. To evaluate the effect of different diets on C. angulata reproductive performance, broodstock were conditioned with different food regimes formulated fundamentally by flagellates (Diet 1 – Pavlova lutheri and Isochrysis galbana clone T‐ISO; Diet 2 – P. lutheri, T‐ISO and Skeletonema costatum) and constituted fundamentally by diatoms (Diet 3 – S. costatum and Chaetoceros calcitrans; Diet 4 – P. lutheri, S. costatum and C. calcitrans). During conditioning, samples of oysters were collected to evaluate condition index, gonadal development and biochemical composition. At the end of the conditioning period, oysters were induced to spawn to evaluate reproductive output (fecundity, fertilization rate and D‐larvae development). The diets had an impact on the gametogenesis process, energy storage and reproductive output performance, being the best results those obtained in broodstock fed with the diatoms‐predominant diets. However, those fed with diets majority flagellates had an unsuccessful performance. Holistic approaches incorporating all results in this study reveal and reinforce the idea that the diatom species used presented the nutritional requirements to C. angulata broodstock, being essential in the conditioning phase. 相似文献
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Isabel Oliveira Cosentino Mario Felipe Alvarez Balaro Felipe Seabra Cardoso Leal Lucas de Figueiredo Cardoso Barbosa Fernanda Martins Gonçalves Gabriel Feliciano Felizardo Marina Monteiro Netto Felipe Zandonadi Brandão 《Reproduction in domestic animals》2020,55(11):1655-1659
This study aimed to evaluate the exogenous progesterone (P4) effect on the luteal function from Day 16 to Day 21 of the oestrous cycle in inseminated goats with unknown pregnancy status. A total of 54 does passed through a short progestin-based synchronization protocol and, on Day 16 of the following oestrous cycle, 27 does received a new P4 device which was retained until Day 21. Blood samples were collected daily from all does during this period, as well as on Day 24. Pregnancy diagnoses were performed on Day 30. Serum P4 values from 26 animals (GNPSP: Group of non-pregnant does with second sponge: n = 8; GNPNSP: Group of non-pregnant does without second sponge: n = 6; GPSP: Group of pregnant does with second sponge: n = 5; GPNSP: Group of pregnant does without second sponge: n = 7) were determined by radioimmunoassay commercial kits. No P4 differences were found between groups (GNPSP: 3.1 ± 2.8; 1.7 ± 1.8; 0.4 ± 1.0; and 0.0 ± 0.0 vs. GNPNSP: 4.4 ± 1.8; 3.0 ± 2.2; 0.8 ± 0.8; and 0.0 ± 0.0 or GPSP: 4.2 ± 1.0; 3.4 ± 0.6; 3.3 ± 1.6; 3.2 ± 0.9; 3.6 ± 1.2; 3.5 ± 1.3; 2.7 ± 1.3 vs. GPNSP: 4.4 ± 1.6; 3.6 ± 1.5; 3.7 ± 1.5; 3.8 ± 1.4; 3.2 ± 1.2; 3.1 ± 1.2; 3.6 ± 1.1; D16, D17, D18, D19, D20, D21, D24, respectively) or for the interaction of group and time. In conclusion, a second progestogen device had no effect on luteolysis or early pregnancy in the following oestrous cycle. 相似文献