Enrichment of Y‐Chromosome‐Bearing Bull Spermatozoa by Swim‐up Through a Column     

A Azizeddin  FA Ashkar  WA King  T Revay 《Reproduction in domestic animals》2014,49(1):e1-e4

With the advancement of assisted reproductive biotechnologies, preselecting the sex of offspring has become an important goal for cattle and other livestock breeding as well as for research. The aim of this study was to investigate the feasibility of producing enriched pools of X‐ or Y‐chromosome‐bearing sperm by vertical swim‐up through a long, narrow column. Sperm recovered from the top portion of the column was predominantly Y‐bearing (60%, p < 0.05), which were capable of fertilizing matured oocytes and produce significantly more male embryos compared with standard swim‐up protocol.  相似文献   

安徽特色农业可持续发展研究     

叶良均  法剑 《安徽农业大学学报》2014,(3):1-8；32

当前安徽特色农业呈不断发展趋势：专业化和产业化不断增强、基础设施逐步改善、科技扶持力度不断增强、农业旅游等功能有所拓展。但是也存在优良品种保护和开发力度不够,生产技术水平相对较低,基层农技推广和农村实用人才难以满足需求,基础设施建设投入不足,主产区生态环境保护不够,产业化有待推进,休闲、观光旅游功能拓展缓慢等问题。建议从五个方面推进安徽特色农业可持续发展：加强基层农业科技人才开发;推进特色农业产业化发展;加强优良品种开发与保护;完善农业基础设施建设;保护生态环境,发展农业旅游。  相似文献   

Marker-trait association and epistasis for brown rust resistance in sugarcane     

Fernanda R. C. Santos  Luciana R. Pinto  Luciana A. Carlini-Garcia  Rodrigo Gazaffi  Melina C. Mancini  Bruna S. Gonçalves  Cibele N. F. Medeiros  Dilermando Perecin  Antônio A. F. Garcia  Anete P. Souza  Maria I. Zucchi 《Euphytica》2015,203(3):533-547

  相似文献   

Beyond host specificity: the biotechnological exploitation of chitolectin from teratocytes of Toxoneuron nigriceps to control non-permissive hosts     

Merlin  Bruna Laís  Pino  Lilian Ellen  Peres  Lázaro Eustáquio Pereira  Prataviera  Fábio  Ortega  Edwin Moises Marcos  Cônsoli  Fernando Luis 《Journal of pest science》2021,94(3):713-727

Journal of Pest Science - The virulence factors (VF) that parasitoids use to regulate the growth and development of their hosts have potential as new events in transgenic plants. VFs are promising...  相似文献   

Effect of plant trichomes on the vertical migration of <Emphasis Type="Italic">Haemonchus contortus</Emphasis> infective larvae on five tropical forages     

Oliveira AL  Costa C  Rodella RA  Silva BF  Amarante AF 《Tropical animal health and production》2009,41(5):775-782

The influence of trichomes on vertical migration and survival of Haemonchus contortus infective larvae (L3) on different forages was investigated. Four different forages showing different distributions of trichomes (Brachiaria brizantha cv. Marandu, Brachiaria brizantha cv. Xaraes, Andropogon gayanus, and Stylosanthes spp.), and one forage species without trichomes (Panicum maximum cv. Tanzania), were used. Forages cut at the post-grazing height were contaminated with faeces containing L3. Samples of different grass strata (0–10, 10–20, >20 cm) and faeces were collected for L3 quantification once per week over four weeks. In all forages studied, the highest L3 recovery occurred seven days after contamination, with the lowest recovery on A. gayanus. In general, larvae were found on all forages’ strata. However, most of the larvae were at the lower stratum. There was no influence of trichomes on migration and survival of H. contortus L3 on the forages.  相似文献   

Comparison between the intestinal microbiome of healthy fish and fish experimentally infected with Streptococcus agalactiae     

Bruna Rafaela dos Santos Silva  Mariana Silveira Derami  Douglas Alvaredo Paixo  Gabriela Felix Persinoti  Wanderley Dias da Silveira  Renato Pariz Maluta 《Aquaculture Research》2020,51(8):3412-3420

Nile tilapia (Oreochromis niloticus) farming is an economic activity that is soaring in the whole world. Septicemia due to Streptococcus agalactiae is the main disease impacting fish farming. The aim of this study was to compare the gut microbiome of healthy animals and animals experimentally infected with S. agalactiae strain 21171A. The microbiome was established with 16S ribosomal DNA next‐generation sequencing (NGS). One hundred Nile tilapias, with an average weight of 35 g, were distributed into two groups. Fifty fish from the challenged group were orally inoculated with 100 μl of a bacterial solution containing 1.98 × 10³ CFU/ml of S. agalactiae strain 21171A, while 50 controls were orally inoculated with sterile saline. After the experiment, 24 fish from the challenged group and 27 fish from the control group were analysed. For both groups, bacteria attached to the mucosa (M) and present in faeces (F) were analysed. The mean of the number of taxa identified in the infected group (M + F) (45.87 ± 30.13) was lower than in the control (M + F) (67.70 ± 21.10) (p < .01). Nineteen bacterial taxa were more abundant in faecal samples from the infected group when compared with the control group (p < .01). Thirty‐nine taxa were associated with mucosa samples from the challenged group when compared to the control samples (p < .01). No OTU was associated with healthy samples. The results demonstrate that the infection with S. agalactiae reduces the variability of the gut microbiota. Moreover, some bacteria proliferate during the infection.  相似文献   

The control of floating macrophytes by grass carp in net cages: experiments in two tropical hydroelectric reservoirs          下载免费PDF全文

Fernando D Domingues  Fernando L R M Starling  Clarice C Nova  Bruna R Loureiro  Leonardo C e Souza  Christina W C Branco 《Aquaculture Research》2017,48(7):3356-3368

The efficiency of grass carp (Ctenopharyngodon idella Val.) for biological control of floating aquatic macrophytes in net cages was assessed in two eutrophic tropical hydroelectric reservoirs through experiments using three macrophyte species (Eichhornia crassipes, Pistia stratiotes and Salvinia auriculata). A total of twenty experiments were performed in these reservoirs with a duration period between 21 and 30 days, during distinct seasons of the year. Sets of experiments were conducted using the three macrophyte species simultaneously in both reservoirs, and additional experiments were performed in one reservoir involving the separate use of each species. All macrophytes demonstrated significant growth in the absence of fish with total per day biomass increase rate ranging from 0.06 to 17.00%. The presence of grass carp significantly reduced macrophyte biomass in both reservoirs independent of fish size, stocking rate and available cage space. In all seasons, grass carp grazing pressure was higher for S. auriculata and lower for P. stratiotes. The results show that grass carp in net cages was able to use aquatic macrophytes as the only food source, controlling massive plant growth (especially S. auriculata and E. crassipes). Fish cages, already implemented in several reservoirs in Brazil, are easily manageable units at relatively low cost. Thus, biocontrol of macrophytes using caged grass carp is proposed as an effective low‐budget ecotechnological tool to control consumable plants while avoiding the removal of desirable aquatic vegetation and the resultant impact on local fauna.  相似文献   

优质杂交粳稻新组合申优 27 的选育     

程灿  曹黎明  周继华  储黄伟  牛付安  孙滨  罗忠永  归连发 《中国种业》2020,(4):61-63

对优质杂交粳稻新组合申优27的选育经过、产量表现、主要特征特性、栽培和制种技术进行了介绍。建立了杂交粳稻"双亲双优、抗性互补"育种技术,有效解决了优质和抗性的协调统一问题。  相似文献   

Gas exchanges and chlorophyll fluorescence of young coffee plants submitted to water and nitrogen stresses     

Bruna Pereira de Souza  Felipe Paolinelli de Carvalho  Marcelo Ehlers Loureiro  Walas Permanhane Sturião 《Journal of plant nutrition》2020,43(16):2455-2465

Abstract

This research aims to evaluate the impact of nitrogen deprivation and water stress on gas exchange and chlorophyll fluorescence in young plants of five cultivars of Arabic coffee. A factorial experiment 5 (cultivars) × 3 (treatments: control without stress, water stress of ?1.5?MPa and stress of N – 0.0?mmol L^?1 N) was carried out in a complete randomized block design with three replicates. Before being submitted to the treatments, the plants were grown in a greenhouse for 240?days, and then transferred to a growth chamber under controlled conditions. Subsequently, after the experimental period of 96?h we measured photosynthetic rate (A), stomatal conductance to water vapor (g_s), transpiratory rate (E), internal and external carbon ratio (Ci/Ca), water use efficiency (A/E), electron transport rate (ETR), actual quantum yield of PS II electron transport (φFSII), and maximum photochemical efficiency of PS II (Fv/Fm). Water stress reduced A, g_s, E, A/E, ETR, φFSII, and Fv/Fm. The nitrogen deficiency reduced ETR, φFSII, and Fv/Fm. Under short-term water stress Catuaí Vermelho maintain the A values due to better stomatal control, reduced water lost by transpiration (E) and better water use efficiency A/E, while Mundo Novo and Acauã show lower damage to Fv/Fm. Short-term nitrogen stress has low impact on A of young plants of Coffea arabica cultivars with adequate N-nutrition.  相似文献