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91.
紫花苜蓿细胞质雄性不育恢复基因的初步定位   总被引:1,自引:0,他引:1  
张世超  王英哲  金艳  陈晶晶  王莹  徐博 《草业科学》2018,35(5):1067-1071
以紫花苜蓿(Medicago sativa)不育系MS-GN-1A为母本,恢复系MS178为父本组合构建BSA分离群体,获得的F1代均表现为雄性可育,在大田种植了221株F2代群体单株,盛花期将花粉颗粒染色后,显微镜下观察统计出,不育的F2代株数为57,可育F2代株数164,并没有观察到半不育植株。将所有植株划分为可育和不育两组,并构建可育和不育DNA混池,混池DNA从可育和不育植株组DNA中各随机抽取20个样品,以此对恢复基因定位。随机挑选160对已知的四倍体苜蓿SSR引物扩增基因池DNA,获得2个具有多态性的分子标记,分别是Mt2c12、AW166,初步定位Rf基因在类群Composite5上。将类群Composite5上的所有引物进行合成,进一步进行引物筛选,最终获得4个具有多态性的标记BI68、Mt2c12、BG267和AW776153,遗传距离分别为19.0、20.9、44.6和72.1cM。  相似文献   
92.
An experiment was conducted to scientifically identify the appropriate feed for Gansu Alpine Fine Wool ewes in order to change the animals' breeding mode, which currently can only be mated at the age of 2.5 years due to insufficient nutritional supply. The experiment selected 48 12-month-old ewes and randomly divided them into group a (Diet 1), group b (Diet 2), group c (Diet 3), and a control group with no supplementary feeding. The feed test was run for 90 days. The rumen pH of groups a and b were very significantly higher (P<0.01) or group c significantly lower (P<0.05) than control group. The rumen ammonia nitrogen, protein nitrogen and total nitrogen of groups a, b and c were all higher than control group (P<0.01). The total volatile fatty acids of group a and b were all higher than the control group (P<0.01), group b significantly higher than group c (P<0.05). The molar ratio of acetic acid and propionic acid in group a was very significantly higher than control group (P<0.01), group b and c were significantly higher than control group (P<0.05). The molar ratio of butyric acid in group a was very significantly higher than group c (P<0.01). The ratio of acetic acid and propionic acid in group b was significantly lower than control group (P<0.05). The number of several rumen fiber-degrading bacteria and protozoa in groups a, b and c were very significantly (P<0.01) or significantly (P<0.05) higher than the control. In conclusion, this study shows that supplementary feeding can positively affect the rumen metabolic parameters and the number of several rumen microorganisms in Gansu Alpine Fine Wool ewes. In general, the effects of Diet 1 were the strongest, while Diet 2 also produced notable improvements. © 2018, Editorial Office of Acta Prataculturae Sinica. All rights reserved.  相似文献   
93.
为评估湖南省某生猪批发市场猪群疫病的发生风险,找出可能的风险因素,便于提出针对性预防措施,采用自行设计的调查问卷,结合访谈和现场调查,对27户经营户进行了调查,并将调查结果和调运数据相结合进行了疫病传播风险定性评估。结果显示:该市场疫病传入的可能性"高",内部传播的可能性"中等",疫病传出的可能性"高"。生猪调运频次多、数量大,经纪人行为复杂,运输车辆清洗消毒不彻底是可能的风险因素。评估结果提示,应尽量减少经纪人行为影响,重点加强对运输车辆的清洗消毒。  相似文献   
94.
Symbiotic N2 fixation by lucerne (Medicago sativa) has capacity to provide significant inputs of N to agro-ecosystems, and the species has also been shown to scavenge soil mineral N and thus act as a sink for excess reactive N. The balance between these two N cycle processes was investigated in an extensive irrigated lucerne growing region where nitrate contamination of groundwater has been reported. We sampled 18 permanent pure lucerne stands under irrigation for standing dry matter, total shoot N, and N2 fixation using 15N natural abundance along with activity of the inducible enzyme nitrate reductase as indicators of use of soil NO3 by lucerne. On average 65% of lucerne N was obtained from symbiotic N2 fixation. Converting standing dry matter estimates to annual N2 fixation amounts we calculated average N2 fixation of 311 kg N/ha, including N in roots and nodules. Uptake of N from soil by lucerne was calculated to be 181 kg N/ha/year. We were not able to identify the source of this soil mineral N, although nitrate reductase activity of lucerne was higher than that of non-N2 fixing species examined.  相似文献   
95.
The effects of various copper (Cu) concentrations on the antioxidative system in the roots of Medicago sativa were explored. The results indicated that the Cu content of the roots reached a value of 854 μg g?1 DW at 10 μm Cu and a value of 4415 μg g?1 DW at 100 μm Cu, suggesting that M. sativa has better ability to tolerate and accumulate Cu than other Cu‐bioaccumulators, and is a potential plant for phytoremediation. Treatment with Cu resulted in a significant increment in the levels of H2O2, O2˙? and OH˙. The reduced form of ascorbate and glutathione reached a peak at 30 μm Cu, and was followed by a sharp depletion to a lower level than that of the control. In contrast, the levels of the oxidised forms of ascorbate and glutathione showed a progressive increment with increasing Cu concentrations, suggesting that the antioxidant system was unable to cope with Cu stress at higher Cu levels. Under the Cu concentrations tested, the activity of catalase (CAT, EC 1.11.1.6), ascorbate peroxidase (APX, EC 1.11.1.11) and glutathione reductase (GR, EC 1.6.4.2) increased at lower Cu concentrations, and then decreased, reaching a maximum at 30 μm of Cu for APX and GR, at 10 μm for CAT, whereas the activities of guaiacol peroxidase (POD, EC 1.11.1.7) were gradually increased with increasing Cu concentrations. PAGE analysis of superoxide dismutase (SOD, EC 1.1.5.1.1) revealed that one band is a Mn‐SOD and five bands are identified as Cu, Zn‐SOD, whereas Fe‐SOD isoforms were not found in the roots of alfalfa. Cu at 10–100 μm increased the intensity of constitutive isozymes of CAT, APX and POD, whereas it decreased the intensity of isozymes of glucose‐6‐phosphate dehydrogenase (G6PDH, EC 1.1.1.49) significantly. The activities of lipoxygenases (LOX, EC 1.13.11.12) were gradually augmented with increasing Cu concentrations, demonstrating that LOXs are probably involved in production of lipid hydroperoxides and superoxide anion. There was a continuous and pronounced enhancement in the activity of esterase (EST, EC 3.1.1.1) in roots treated with 10–30 Cu μm , whereas EST activity in roots exposed to above 30 μm Cu declined, suggesting that EST plays a protective role under lower Cu concentrations stress.  相似文献   
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98.
Umma Tamima 《林业研究》2016,27(4):853-861
The objective was to evaluate the performance of the co-management of Nishorgo Support Project at Chunati Wildlife Sanctuary in Bangladesh. I adopted the Focus Groups Discussion method for opinion survey and applied the SWOTAHP technique for data analysis. Local people did not participate in the decision-making process of forest management and they perceived co-management as a threat to their livelihoods. Moreover, mistrust and misunderstanding among different stakeholders, political and ethical conflicts, lack of property rights of tribal communities, and lack of accountability and transparency were identified as the drawbacks of co-management.  相似文献   
99.
AM79 aro A(WO/2009/059485)基因是从草甘膦高度污染的土壤中克隆的、具有我国自主知识产权的新型草甘膦抗性基因,具有重要应用价值。为进一步解析AM79 EPSPS蛋白的作用机制,本研究对此蛋白的活性位点进行了研究。进化树分析显示AM79 EPSPS属于Ⅰ型EPSPS。序列比对结果表明AM79 EPSPS中第107位的丙氨酸(Ala),第114位的苯丙氨酸(Phe),第355位的Ala和第356位的组氨酸(His)是特异的。采用重叠延伸PCR介导的核苷酸定点突变技术,对这些保守的氨基酸位点进行定点突变。将AM79 aro A及其突变基因转入大肠杆菌(Escherichia coli)aro A缺陷型菌株ER2799中,并进行草甘膦抗性鉴定。结果显示,Phe114、Ala355和His356等氨基酸的突变,使AM79 EPSPS蛋白的草甘膦抗性降低,表明这些氨基酸位点对于维持AM79 EPSPS高抗草甘膦的能力是必需的。同源建模结果表明,这些保守氨基酸位点的突变,使AM79 EPSPS蛋白的结构发生变化,这可能是导致突变蛋白草甘膦抗性能力降低的原因。两个Ⅰ型EPSPS(荧光假单杆菌(Pseudomonas fluorescens)G2EPSPS和拟南芥(Arabidopsis thaliana)EPSPS)对应氨基酸突变后,其草甘膦抗性没有明显变化,表明AM79 EPSPS中几个特异的氨基酸位点的功能在Ⅰ型EPSPS中并不是保守的。本研究结果为解析AM79 EPSPS高抗草甘膦的作用机理及对AM79 EPSPS进行定向进化提供了理论依据。  相似文献   
100.
以番茄为试验材料,在田间大棚设施条件下,选用白、蓝、黑、红、绿5种不同颜色的遮阳网,探讨不同光质对番茄营养与风味品质的影响。结果表明,在青熟期,黑色光质促进了总氮、蛋白氮以及非蛋白氮的积累。青熟期到转色期,白色光质的番茄有机酸总量较青熟期增加了4.57倍,蓝色和绿色光质提高了番茄的总糖和还原糖含量。从转色期到成熟期,番茄氨基酸含量大小表现为蓝色>绿色>黑色>红色>白色;黑色光质的番茄有机酸总量较转色期增加了27.8%;红色光质提高了番茄红素含量和Vc含量,降低了硝酸盐含量;白色、红色和绿色光质增加了番茄的总糖和还原糖含量。番茄主要风味物质(>30 μg/kg)为水杨酸甲酯、6-甲基-庚烯-2-酮、柠檬烯、反-2-己烯醛。红光使番茄水杨酸甲酯、6-甲基-庚烯-2-酮和己烯醛含量较白光增加了11.6%、20.2%和17.2%。在大田设施条件下,转色期到成熟期可以采用红色光质提高番茄果实营养品质和风味。  相似文献   
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