全文获取类型
收费全文 | 170篇 |
免费 | 18篇 |
专业分类
林业 | 12篇 |
农学 | 11篇 |
40篇 | |
综合类 | 9篇 |
农作物 | 9篇 |
水产渔业 | 33篇 |
畜牧兽医 | 57篇 |
园艺 | 6篇 |
植物保护 | 11篇 |
出版年
2024年 | 2篇 |
2023年 | 8篇 |
2022年 | 5篇 |
2021年 | 10篇 |
2020年 | 15篇 |
2019年 | 15篇 |
2018年 | 13篇 |
2017年 | 13篇 |
2016年 | 15篇 |
2015年 | 9篇 |
2014年 | 7篇 |
2013年 | 18篇 |
2012年 | 15篇 |
2011年 | 14篇 |
2010年 | 5篇 |
2009年 | 5篇 |
2008年 | 4篇 |
2007年 | 8篇 |
2006年 | 3篇 |
2002年 | 1篇 |
2001年 | 2篇 |
2000年 | 1篇 |
排序方式: 共有188条查询结果,搜索用时 78 毫秒
71.
Maura da Cunha Darlí Grativol Keller Ivan Cunha Bustamante Filho Jorge André Sacramento de Magalhães Valdirene Moreira Gomes Wanderley de Souza José Inácio Lacerda Moura José Luiz Bezerra Flávio Costa Miguens 《Journal of General Plant Pathology》2010,76(1):74-83
Phytomonas wilt or Hartrot is a fatal disease of palm (Arecaceae) species including Cocos nucifera (coconut) and is caused by a phloematic trypanosomatid, a promastigote parasite that inhabits phloem sieve elements of disease
palms. In the present work, we described the morphology of the interaction between a phloematic trypanosomatid (Phytomonas staheli) and C. nucifera. Two varieties and one ecotype of the adult coconut palm from northeast and southeast Brazil were analyzed, totaling 34,000
plants. Coconut palm losses due to Hartrot varied according to the variety or ecotype and geographic area. Occurrence of Hartrot
was insignificant in Rio de Janeiro state (southeast), but in Bahia state (northeast) losses were substantial when appropriate
cultural practices were not applied. Symptomatic and healthy palm tissues were analyzed by light and electron microscopy.
Laboratory diagnoses revealed the twisted promastigote form of phloematic trypanosomatids in the extracts of shoot apex, leaves,
stems and inflorescence in diseased plants, but not in the healthy ones. No parasites were found in the roots. Although the
general anatomy of healthy and diseased palms was similar, callose deposition in the sieve plates was revealed by histochemistry
and immunocytochemistry in the diseased tissue. Plugging by the P-protein and plastid alterations was also observed. Our observations
strongly suggest that parasite traffic between sieve elements took place, although their cell bodies were larger than the
sieve pores. Phloematic trypanosomatid proliferation in the sieve tube elements might interrupt the transport of phloem or/and
consume plant nutrients. In addition, an association between the percentage of sieve elements colonized by pathogen in palm
tissues and disease severity was established. 相似文献
72.
73.
Flávia Cristina de Oliveira e Silva Naiara Taís Alves da Silva Joana Ribeiro da Glória João Carlos de Freitas Alves Ana Luiza da Costa Cruz Borges Lúcio Carlos Gonçalves José Avelino Santos Rodrigues Diogo Gonzaga Jayme 《Grass and Forage Science》2023,78(2):317-325
This study aimed to determine whether using inoculants and re-ensiling in sorghum silages affect the intake and feeding behaviour, apparent digestibility, digestible energy, and nitrogen balance of sheep in maintenance. Half the sorghum was inoculated on the day of harvest, and the other half received the same inoculation volume but with water. Sorghum was ensiled in 100 experimental metal drum silos of 200 L covered with plastic: 50 silos with inoculants and 50 without them. After 56 days, 25 drums with inoculants and 25 without were exposed to air for 48 h. The other silos remained closed. The treatments were arranged in a 2 × 2 factorial scheme with inoculation and re-ensiling. The sheep received the silages after 211 days of ensiling and 155 days of re-ensiling to determine the intake, apparent digestibility, and feeding behaviour of animals. The experimental design was a simultaneous double 4 × 4 Latin square. The re-ensiling process increased silage pH, N-NH3.TN−1, butyric acid, and propionic acid. The inoculant increased propionic acid in ensiled and re-ensiled silages. Lactic acid concentration presented a statistical interaction with the inoculated and ensiled silage, 58% higher than the other treatment averages. The ADFap digestibility showed a complex interaction, in which the control ensiled and the inoculated and re-ensiled silages were about 35% lower than the inoculated ensiled silage. The Nbal:Nint ratio (g.g−1) in the inoculated and re-ensiled silage had lower nitrogen retention than intake compared with the other treatments. These results indicate that exposing inoculated silages to air does not compromise their use in sheep feeding. 相似文献
74.
Fábio Raphael Pascoti Bruhn Guilherme Loureiro Werneck David Soeiro Barbosa Daniel Cardoso Portela Câmara Taynãna César Simões Lia Puppim Buzanovsky Anna Gabryela Sousa Duarte Saulo Nascimento de Melo Diogo Tavares Cardoso Lucas Edel Donato Ana Nilce Silveira Maia-Elkhoury Vinícius Silva Belo 《Zoonoses and public health》2024,71(2):144-156
75.
Velasquez A. E. B. Higuti V. A. H. Guerrero H. B. Gasparino M. V. Magalhães D. V. Aroca R. V. Becker M. 《Precision Agriculture》2020,21(2):349-368
Precision Agriculture - Severe working conditions, the cost reduction need and production growth justify the adoption of technological techniques in agricultural production. Currently, Global... 相似文献
76.
Zaw Win Tu Tu Campbell Angus Soares Magalhães Ricardo J. Oo Kyaw Naing Henning Joerg 《Tropical animal health and production》2019,51(3):643-654
Tropical Animal Health and Production - The central dry zone of Myanmar is the area with the highest density of small-scale livestock farmers under harsh environmental condition. In this study, we... 相似文献
77.
Rafaela Pereira Cristiano Bortoluzzi Ademir Durrer Naiara Simarro Fagundes Adriana Ayres Pedroso Jaqueline Moreira Rafael Júlia Elidia de Lima Perim Kelen Cristiane Zavarize Glaucia Samira Napty Fernando Dini Andreote Diogo Paes Costa Jos Fernando Machado Menten 《Journal of animal physiology and animal nutrition》2019,103(1):72-86
The purpose of this study was to verify the ability of a probiotic in the feed to maintain the stability of the gut microbiota in chickens after antibiotic therapy and its association with growth performance. One thousand six hundred twenty 1‐day‐old Cobb male were housed in floor pens (36 pens, 45 birds/pen) and were fed corn‐/soya bean meal‐based diets supplemented with or without probiotic (Bacillus subtilis) during the entire rearing phase. From 21 to 24 days of age (three consecutive days), the chickens were submitted to antibiotic therapy via drinking water (bacitracin and neomycin) in order to mimic a field treatment and induce dysbiosis. Growth performance was monitored until 42 days of age. At 2, 4 and 6 days after antibiotic therapy, three chickens from each pen were euthanized and the contents of the small intestine and caeca were collected and pooled. The trial was conducted with four treatments and nine replicates in a 2 × 2 factorial arrangement for performance characteristics (with and without probiotic × with and without antibiotic therapy); for the intestinal microbiota, it was in a 2 × 2 × 3 factorial arrangement (with and without probiotic × with and without antibiotic therapy × 2, 4 and 6 days after the antibiotic therapy) with three replicates per treatment. Terminal restriction length polymorphism (T‐RFLP) analysis showed that the structure of gut bacterial community was shaped by the intestinal segment and by the time after the antibiotic therapy. The number of 16S rDNAs copies in caecum contents decreased with time after the therapeutic treatment. The antibiotic therapy and dietary probiotic supplementation decreased richness and diversity indexes in the caecal contents. The improved performance observed in birds supplemented with probiotic may be related to changes promoted by the feed additive in the structure of the intestinal bacterial communities and phylogenetic groups. Antibiotic therapy modified the bacterial structure, but did not cause loss of broiler performance. 相似文献
78.
79.
B. N. Porto J. D. Alves P. C. Magalhães E. M. Castro N. A. Campos K. R. D. Souza M. M. Magalhães C. A. Andrade M. O. Santos 《Journal of Agronomy and Crop Science》2013,199(2):134-143
The aim of the present study was to find out the effect of calcium on flooded maize seedlings by anatomical and ultra‐structural analyses and by measuring the enzyme activity and gene expression of polygalacturonase (PG) and superoxide dismutase (SOD). For this, maize seeds were placed to germinate in germination paper saturated with CaCl2 0.75 %. Then, 4‐day‐old seedlings were subjected to flooding in the presence or absence of CaCl2. Mesocotyl sections were sampled daily for the anatomical and ultra‐structural analyses, RT‐qPCR and activity of SOD and PG. The results showed that the presence of calcium in the flooding buffer increases the tolerance of maize seedlings by 1 day when compared to seedlings flooded in the absence of this element. The reason for this longer survival is that calcium maintains the integrity of the cell wall and attenuates the effects of oxidative stress. Owing to this fact, the seedlings remained alive and firm for up to 7 days. 相似文献
80.
Adão Felipe dos Santos Otoniel Magalhães Morais Renato de Mello Prado Aguinaldo José Freitas Leal Rouverson Pereira da Silva 《Communications in Soil Science and Plant Analysis》2017,48(10):1123-1131
The beneficial effect of corn seed treatment with zinc (Zn) is directly related to the source used. The excess of this micronutrient causes seedling stress and reduces growth. Thus, assuming that the use of exogenous phytohormones can minimize such effects, we evaluated different doses and sources of Zn for the treatment of maize seeds with or without salicylic acid. The experiment took place in the laboratory, and two factorial experiments, 2 × 4 + 1, were performed in a randomized design. The seeds were treated with either ZnO or ZnSO4 at doses of 0.5, 1, 2, and 3 g.kg?1 seed with four replications, differing only by the addition of 4.14 mg L?1 salicylic acid. Treating seeds with Zn and salicylic acid did not affect germination. ZnO led to a greater increase in dry mass in corn seedlings as compared with zinc sulfate, especially at higher doses (2 and 3 g kg?1 seed). Seed treatment with sulfate reduces root and shoot length, and salicylic acid did not attenuate this toxic effect. Dry mass is not affected when oxide is used. Salicylic acid reduces the accumulation of zinc in the treatment of corn seeds, regardless of the source used. 相似文献