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排序方式: 共有606条查询结果,搜索用时 15 毫秒
1.
为研究不同接种方法和接种时期对玉米拟轮枝镰孢穗腐病(Fusarium verticillioides ear rot,FER)抗性鉴定的影响,选取高抗×高抗、高抗×高感、高感×高感组合各3份,2022年在北京顺义和河南新乡分别用针刺果穗注射法与双牙签法在玉米吐丝后5、10、15 d进行接种。结果表明,吐丝后5、10和15 d接种,针刺果穗注射法分别比双牙签法的平均病情严重度高6.3%、3.9%和1.8%;吐丝后5 d接种,不同组合采用针刺果穗注射法接种未达到显著差异,采用双牙签法达到极显著差异(P<0.01);吐丝后10 d和15 d接种,不同组合使用针刺果穗注射法均达到极显著(P<0.01)差异,牙签法均未达到显著差异。采用双牙签法接种时,建议吐丝后5 d接种;采用针刺果穗注射法接种时,建议吐丝后10~15 d接种。  相似文献   
2.
为获得生长在沙漠深处不同类型桑树基因资源的持水力差异信息,采用自然脱水法,对黑桑、白桑、粉桑和雄桑等不同类型的20份沙漠桑基因资源的失水过程进行了测定;研究结果表明,沙漠桑树分为强持水型、中等持水型和弱持水型,黑桑、白桑和粉桑类型桑树的持水能力较雄桑类型桑树强;根据枝条、叶片等同器官持水能力强弱不同,多数沙漠桑叶片的持水能力不太强,初步认为枝条的持水能力较叶片强。  相似文献   
3.
AIM: To investigate the effect of T-bet plasmid gene transfer to airway on allergen induced airway inflammation in a murine asthmatic model. METHODS: A mouse asthma model was established by sensitization with ovalbumin (OVA). Forty C57BL/6 mice were divided into 4 groups (10 mice in each group): the normal control group (group A), the asthmatic model group (group B), the pcDNA3 plasmid group (group C), and the pcDNA3-T-bet group (group D). The animals in group B, C and D were sensitized and challenged with OVA. The animals in group A were applied with normal saline. pcDNA3 plasmid at dose of 50 μg was intranasally administered at 24 h before intranasal challenges to the mice in group C, and the 50 μg pcDNA3-T-bet plasmid for the mice in group D. Bronchial alveolar lavage fluid (BALF) was collected and lung tissues were resected at 48 h after OVA challenge for later assay. RESULTS: After administration with pcDNA3-T-bet plasmid, high level of T-bet expression at 48 h was detected in the lung tissue by Western blotting. In pcDNA3-T-bet treated asthmatic models, histological evaluation revealed the significant suppression of eosinophil peribronchial and perivascular infiltration, and reduction of epithelial damage. The numbers of eosinophils, neutrophils and lymphocytes in BALF from pcDNA3-T-bet treated mice were significantly reduced compared to those in asthmatic control group (P<0.05). The level of IL-4 in BALF was significantly decreased in pcDNA3-T-bet group compared to that in asthmatic control group (P<0.05), while the level of IFN-γ in BALF was significantly increased in pcDNA3-T-bet group. No significant change of inflammation cells and cytokines in pcDNA3 plasmid group and asthmatic control group was observed (P>0.05). CONCLUSION: Intranasal pcDNA3-T-bet plasmid transfer inhibits asthmatic airway inflammation in the murine asthmatic model, suggesting a new therapeutic strategy for allergic asthma.  相似文献   
4.
甜橙新品种——桂橙一号的选育   总被引:4,自引:0,他引:4  
桂橙一号是冰糖橙优良芽变株系,成熟期11月下旬,平均单果质量154.0g,大小较均匀,可食率75.66%,可溶性固形物含量14.6%,全糖12.47%,酸0.38%,风味浓郁,有蜜香,甜脆化渣,树形开张,丰产稳产,商品性好,适应性强,果实耐贮藏。  相似文献   
5.
以白玉菇为材料,通过单因素试验分析热风温度、切片厚度和装载量对白玉菇干燥特性和干燥品质的影响,并通过正交试验对干燥参数进行优化。结果表明,升高热风温度、减小切片厚度、减小装载量可以有效降低白玉菇的干基含水率,加快干燥速率。温度对干燥速率的影响最大,然而温度过高容易造成白玉菇干燥表面的硬化,反而降低了干燥中后期的干燥速率。干基含水率大,温度、切片厚度和装载量对干燥速率的影响也增大。通过对亮度、复水比、维生素C含量和感官评分的综合评定,得到最优工艺参数为:热风温度60℃,切片厚度2 mm,装载量15 g·dm^-2。  相似文献   
6.
本文就如何提高生产管理的技术水平和经济效益,谈谈肉用商品鸭散户饲养管理的一些看法。1选择优良品种饲养肉用商品鸭目前基本选择樱桃谷杂及丽  相似文献   
7.
To identify viruses in Henan tobacco-planting areas, from 2015 to 2017 and 2019, 288 symptomatic tobacco samples were collected and then subjected to small RNA sequencing. Results showed that at least 7 viruses were detected from these samples which including four previously reported viruses, cucumber mosaic virus (CMV), tobacco mosaic virus (TMV), potato virus Y (PVY) and tobacco vein banding mosaic virus (TVBMV). Other three viruses, wild tomato mosaic virus (WTMV), brassica yellows virus (BrYV), and cycas necrotic stunt virus (CNSV) were firstly detected in Henan province. However, tobacco etch virus (TEV) and tobacco ringspot virus (TRSV) were not detected from these samples. In addition, CMV, TMV, PVY, TVBMV, and BrYV were the dominant viruses infecting tobacco in Henan Province.  相似文献   
8.

裂褶菌多糖是裂褶菌 (Schizophyllum communer Fr.) 子实体、菌丝体或发酵液提取的具有β-(1,6) 分支的 β-(1,3)-D葡聚糖。为了探究裂褶菌多糖饲养凡纳滨对虾 (Litopenaeus vannamei) 的效果,选用12口凡纳滨对虾养殖池,按照裂褶菌多糖的添加量 (质量分数),分别设置0% (C组)、0.5% (S1组)、1.0% (S2组) 和2.0% (S3组) 4组进行56 d的饲养实验,分析对虾的生长、血清理化、免疫指标和肠道菌群等变化。结果显示,S2组的终末体质量、平均体质量增长率和特定生长率均显著高于C、S1和S3组 (P<0.05);S2、S3组内层上皮细胞的高度显著高于C和S1组 (P<0.05)。与对照组相比,S2和S3组血清中的尿酸含量显著降低 (P<0.05),S1组则无显著性差异 (P>0.05)。S2和S3组血清中溶菌酶、总一氧化氮合成酶、酚氧化酶和碱性磷酸酶的活性均显著高于对照组 (P<0.05)。S2组过氧化氢酶、超氧化物歧化酶活性和总抗氧化能力显著高于对照组 (P<0.05);各实验组血清丙二醛含量均有不同程度的降低 (P>0.05)。肠道菌群Ace、Chao1、Shannon、Simpson指数均无显著性差异 (P>0.05)。在门水平上,与对照组相比,添加裂褶菌多糖的各实验组变形菌门相对丰度均下降,软壁菌门升高。在属水平上,与对照组相比,S2组中FormosaPseudoruegeriaMuricauda和鲁杰氏菌属 (Ruegeria) 相对丰度均显著升高 (P<0.05),而弧菌属 (Vibrio) 相对丰度显著降低 (P<0.05)。结果表明,在饲料中添加1.0%的裂褶菌多糖能显著提升凡纳滨对虾的生长性能、免疫力和抗氧化能力,增加肠道有益菌丰度,降低有害菌丰度。

  相似文献   
9.
An experiment was conducted to investigate the effect of dietary iron supplement on growth, haematology and microelements of juvenile grouper, Epinephelus coioides. Casein–gelatine‐based diets supplemented with 0, 50, 100, 150, 200 and 250 mg kg−1 iron from ferrous sulphate were fed to grouper (mean initial weight: 21.0 ± 0.2 g) for 8 weeks. Weight gain was highest in fish fed the diet supplemented with 100 mg kg−1 iron, intermediate in fish fed diets with 50, 150, 200 and 250 mg kg−1 iron and lowest in fish fed the basal diet. Feed efficiency followed a similar trend except that the lowest value was in fish fed the basal diet and the diet supplemented with 250 mg kg−1 iron. Hepatic iron was highest in fish fed diets supplemented with iron ≥100 mg kg−1, followed by fish fed diet with 50 mg kg−1 iron and lowest in fish fed the basal diet. The whole‐body iron was lowest in fish fed the basal diet but not significantly different from other groups, as judged by anova . Iron supplement to the basal diet had no significant effect on haematological parameters (red blood cell count, haematocrit and haemoglobin), hepatic copper concentration or manganese, zinc concentration in liver and whole body. Broken‐line analysis of hepatic iron indicated that iron supplementation of 100 mg kg−1 satisfied the hepatic iron storage and that further supplementation did not expand the iron status.  相似文献   
10.
为了更好地开展中兽医药与方剂学课程的教学和科学研究,使学生了解和掌握中草药物和方剂的理论学习,通过制作中草药饮片标本、干制标本、蜡叶标本和浸制标本,不断地建立和完善中草药标本室,也可以通过中草药标本二维码数据库的建立、常见植物标本的种植栽培,以及野外采集中草药实践教学的实施,提高学生对中兽医药与方剂学课程的学习质量,以期为今后临床实践和应用打下良好的理论基础。  相似文献   
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