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41.
植物组织培养:最新进展和潜在的应用(英文) 总被引:3,自引:0,他引:3
植物组织培养体系在基础研究和商业应用中具有巨大的潜能,例如园艺产业。组织培养过程伴随着一系列关于形态学、生理学、生物化学、分子和表观遗传的改变。分子水平的改变主要包括基因突变、DNA重组、染色体变异和表观遗传调控(DNA甲基化、组蛋白修饰、染色质重塑、小RNA调节)。这些改变被认为能促进外植体对培养环境的适应并有益于随后的形态发生。目前,组培已在商业应用和细胞生物学、遗传学、生物化学等基本研究中发挥了重要作用。本文重点介绍了植物组织培养的原理概念、培养基的制作、外植体的选择、各种激素的作用机理、植物离体快速繁殖的3大难题(外植体的污染、褐变、试管苗的玻璃化)以及防止措施,并详细阐述了植物离体快繁、无病毒苗木培育、培养细胞突变体、人工种子和离体培养期间分子水平的变化。 相似文献
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Objective: To investigate the relative efficacy and safety of the anthelmintic naphthalophos in sheep, either given alone or in combination with benzimidazole (fenbendazole and albendazole) or levamisole anthelmintics.
Design: A parasitological study using faecal egg count reduction tests, a validating slaughter trial and field safety trials.
Procedure: Faecal egg count reduction tests were carried out on 13 farms. Naphthalophos and combinations of naphthalophos with levamisole and fenbendazole were included in the drench tests. On one property a controlled efficacy study was carried out to validate faecal egg count reduction test findings. In this trial, sheep were slaughtered 10 days after treatment and the remaining parasites recovered from the gastro-intestinal tract. Safety trials were carried out on eight farms where approximately 50 000 sheep were treated with naphthalophos and albendazole that were tank mixed in the backpack.
Results: The efficacy of naphthalophos alone in faecal egg count reduction tests ranged from 59 to 98% with one test showing 95% reduction. The efficacy of naphthalophos and levamisole ranged from 74 to 100%, with 5 farms showing 95% reduction. The efficacy of naphthalophos and fenbendazole ranged between 88 and 100% with 95% reduction achieved on 10 farms. The controlled efficacy study showed a good correlation between the faecal egg count reduction tests and numbers of parasites recovered, except for Nematodirus where the faecal egg count reduction tests overestimated efficacy. The mortality rate in the safety trials was 0.05%, with most fatalities occurring on one farm.
Conclusion: The combination of naphthalophos and fenbendazole was more effective than a combination of naphthalophos and levamisole, and will provide a sufficiently safe drench rotation option. 相似文献
Design: A parasitological study using faecal egg count reduction tests, a validating slaughter trial and field safety trials.
Procedure: Faecal egg count reduction tests were carried out on 13 farms. Naphthalophos and combinations of naphthalophos with levamisole and fenbendazole were included in the drench tests. On one property a controlled efficacy study was carried out to validate faecal egg count reduction test findings. In this trial, sheep were slaughtered 10 days after treatment and the remaining parasites recovered from the gastro-intestinal tract. Safety trials were carried out on eight farms where approximately 50 000 sheep were treated with naphthalophos and albendazole that were tank mixed in the backpack.
Results: The efficacy of naphthalophos alone in faecal egg count reduction tests ranged from 59 to 98% with one test showing 95% reduction. The efficacy of naphthalophos and levamisole ranged from 74 to 100%, with 5 farms showing 95% reduction. The efficacy of naphthalophos and fenbendazole ranged between 88 and 100% with 95% reduction achieved on 10 farms. The controlled efficacy study showed a good correlation between the faecal egg count reduction tests and numbers of parasites recovered, except for Nematodirus where the faecal egg count reduction tests overestimated efficacy. The mortality rate in the safety trials was 0.05%, with most fatalities occurring on one farm.
Conclusion: The combination of naphthalophos and fenbendazole was more effective than a combination of naphthalophos and levamisole, and will provide a sufficiently safe drench rotation option. 相似文献
44.
营口农业水资源现状及利用途径的研究 总被引:1,自引:0,他引:1
水是农业生产的命脉,农业水资源短缺,影响到农业生产和农业经济发展,我省是我国水资源严重匮乏的地区之一,营口市又是省内几个重度缺水地区之一,近几年来,营口市在农业水资源利用上面临降水量逐年减少,地表和地下水资源持续下降,农业用水量和耗水增长迅速,水污染严重等一系列问题。因此要通过多途径增加农业水资源总量,节约农业用水,防治水污染,加快农业生态建设和水利设施建设等措施提高农业水资源利用效率。 相似文献
45.
大庆地区草地退化驱动机制分析 总被引:3,自引:0,他引:3
为探讨资源型城市大庆市草地退化驱动机制,找出驱动草地退化的主导因素,为科学保护现有草地资源和有效治理退化草地提供依据和参考.该文在定性描述大庆地区草地退化驱动因素的基础上,运用主成分分析和多元线性回归的方法,选取与草地退化密切相关并比较容易获取的数据作为变量,对大庆地区草地退化的主要影响因素进行了定量分析.根据对草地退化的影响程度,影响因子排序为:畜牧业产值>人口密度>油井个数>总人口>大牲畜存栏>人均居住面积>GDP>工业产值>盐碱、沙化.并且根据大庆地区1988—2001年不同退化程度草地的面积与驱动因子建立多元线性回归模型,对不同退化程度草地面积变化的驱动机制进行了分析.结果表明,不合理的人类活动与石油开采加工的工业化进程占用大量草场是大庆地区草地退化的主要驱动因素,决定着草地生态系统逆向演替的总体趋势.最后根据以上分析提出大庆地区草地退化的防治措施. 相似文献
46.
电场处理油葵种子对其萌发期水分胁迫敏感性的影响 总被引:3,自引:1,他引:3
用不同电场强度处理油葵种子15min,以PEG(聚乙二醇)模拟水分胁迫,测定电场处理对种子萌发期抗旱性的影响.结果表明:在0~6.0kV/cm场强范围,不同电场强度,对种子水分胁迫的敏感性的影响程度不同.随着电场强度的增加,种子敏感性以振荡关系变化.适当电场处理条件能够显著地提高种子的吸水率,减轻细胞膜对干旱胁迫的敏感性,从而减小水分胁迫对细胞膜的伤害.提高种子抗旱性最佳电场处理条件的选取与处理时间和电场强度有关. 相似文献
47.
In this article,the characteristic of the field plastic mulch, the craft for mechanization removal and land preparation of plastic mulch and the mechanism frequently used in the removal and land preparation of plastic mulch were introduced, which offered references for the design of removal mechanism and land preparation of plastic mulch and structural optimization combination of working components. 相似文献
48.
木立芦荟和三角芦荟的组织培养和低成本快繁 总被引:1,自引:0,他引:1
以MS+BA3+NAA0.2和MS+BA4+NAA0.2分别为木立芦荟(AloearborescensMill)和三角芦荟(AloemitriformisMill)的诱导培养基.1/2MS+BA2+NAA0.2和MS+BA3+NAA0.2分别为两种芦荟的增殖培养基,对茎段、茎尖和吸芽进行离体培养.以4周为一个继代周期,每周期可增殖6~8倍,现已经过26个继代周期,一个外植体每年可增殖至813个芽苗.为减轻褐化,降低温度至22℃、光照强度800lx,附加活性炭3~5g@L-1.用白糖替代蔗糖,自来水替代蒸馏水,果酱瓶替代三角瓶,既不影响培养效果又可降低生产成本. 相似文献
49.
新型水稻钵体摆栽秧盘及秧盘注塑模具的设计 总被引:1,自引:0,他引:1
通过对现有水稻钵体摆栽秧盘结构的改进设计,可以大大提高秧盘的使用寿命,并设计出用于改进后的秧盘生产用的注塑模具。 相似文献
50.
紫茎泽兰精油各馏份对4种仓库害虫的杀虫活性 总被引:23,自引:1,他引:23
用紫茎泽兰精油的20℃ ̄150℃,150℃ ̄200℃,200℃ ̄230℃,230℃ ̄300℃和300℃以上馏份,分别以44.44mg/L的熏蒸浓度处理米像、玉米象、绿豆象和蚕豆象,结果表明,在5个馏份中,以150℃ ̄200℃馏份的杀虫活性最高,其次是20℃ ̄150℃和220℃ ̄230℃馏份,而300℃以上馏份的杀虫活性最低。进一步的生测结果表明,150℃ ̄200℃馏份对米象、玉米象、绿豆象和蚕豆象 相似文献