Bioavailability and Rhizotoxicity of Cd to Pea (Pisum sativum L.)     

Yonghong Wu  William H. Hendershot 《Water, air, and soil pollution》2010,208(1-4):29-42

Risk assessment of cadmium (Cd) contamination in soils requires identifying the bioavailable portion of the total Cd, a portion that is determined by environmental conditions such as pH and calcium (Ca) level in soils and by the physiological processes going on in the plant roots. Growth tests in solutions were conducted to develop a terrestrial biotic ligand model to describe uptake and rhizotoxicity of Cd to pea (Pisum sativum L. cv. Lincoln). Inhibition concentration associated with a 50% reduction in root elongation (IC₅₀) values were found to vary with external Ca²⁺ and H⁺ activities. Root-bound Ca was found to reach a plateau of about 63 µmol g^?1 (dry weight) although Ca treatment increased from 0.04 to 2 mmol L^?1. When experimental treatments (e.g., pH 6, Ca 0.2 to 2 mM) resulted in sufficient Ca supply, dose–response curves relating root elongation to root-bound Cd could be modeled with Weibull equations; IC₅₀ values were expressed in terms of root-bound Cd concentration. When the treatments (e.g., pH 4 or 5, Ca 0.04 mM) suggested a low Ca supply, root elongation was more sensitive to Ca content and root-bound Ca concentration became the dominant predictor variable. Cd accumulation was modeled by treating the pea roots as an assemblage of biotic ligands with known site densities (Q _Lj ) and proton binding constants (K _HLj ). The logK _Ca and logK _Cd values were established using measured root-bound ion concentrations and solution chemistry. The logK _Ca values were negatively correlated to root Ca contents. The logK _Cd values were positively correlated to logK _Ca values. Explanations for the changing of constants are discussed.  相似文献   

红地球葡萄四倍体芽变新品种红太阳的选育     

武瑞俊  王耀胜 《山西果树》2011,(3):3-4

红太阳是在山西省清徐县一农户红地球葡萄园中发现的芽变新品种,果穗长圆锥形,平均重1250g;果粒近圆形,平均粒重18g。果皮厚,颜色同红地球。可溶性固形物含量16%。在当地9月上旬成熟。该品种树势强壮,但顶端优势不明显,管理较红地球省工。  相似文献   

ATM多级分层网络及其交换策略     

伍仁勇  段正华 《湖南农业大学学报(自然科学版)》1999,26(3)

多级分层网络是ＡＴＭ中实现自由交换虚电路的一种实现策略之一。由此提出了一种递归扩展的层次式互联网络结构，分析了号码制度，信令协议等技术问题，并研究了这种对应于分层地址分配的层界面ＡＴＭ交换机的排队模型。  相似文献   

虫孔注药防治黑杨桑天牛幼虫试验     

吴浙东  张秀岳  邓玉英  陈永富 《河北林果研究》2000,15(3):273-275

为提高防治效果，１９９９年４月在浙江省武义县后陈等地黑杨林内，采用不同浓度的７种农药对黑杨桑天牛幼虫进行虫孔注射防治试验，结果表明，选用内吸性农药４０％氧化乐果乳油和５０％甲胺磷乳油，每虫也用量４ｍｌ，防治效果９０－１００％。  相似文献   

浅谈旌德秋冬季农业开发     

吴建兵  王长根 《安徽农学通报》2010,16(3):23-24,33

提出了旌德秋冬季农业开发的建议：提高认识,合理布局,扩大规模,科技推动,产业化经营,推动旌德生态农业发展。  相似文献   

国内外农业信息化建设对佳木斯地区的启示   总被引：2，自引：1，他引：1  

邵东伟  王俊发  吴贵福  宋学东 《农机化研究》2010,32(8)

分析借鉴国内外农业信息化建设的经验,对加快实现佳木斯地区农业的信息化具有重要意义.为此,当前世界上农业信息化建设工作比较发达的欧美国家信息化建设的工作经验;分析了开展此项工作相对较晚的亚洲国家农业信息化建设的情况以及我国近年来农业信息化工作的情况.由此得出国内外经验给佳木斯地区开展农业信息化建设工作的4点启示:一是发挥政府的宏观调控职能是开展好农业信息化建设的保障;二是健全基础设施是开展好农业信息化建设的前提;三是搞好信息数据库建设是开展好农业信息化建设的基础;四是做好科研、教育和推广的有机结合是开展好农业信息化建设的必然.  相似文献   

Antiviral flavonoids from Mosla scabra     

Qiaofeng Wu  Chenhuan Yu  Yunliang Yan  Jing Chen  Chunchun Zhang  Xinxin Wen 《Fitoterapia》2010,81(5):429-433

An ethanolic extract and ethyl acetate fraction (EFMS) prepared from Mosla scabra showed potential inhibition against influenza viruses. The compounds isolated from EFMS were elucidated to be ursolic acid (1), 5-hydroxy-6,7-dimethoxyflavone (2), 5-hydroxy-7,8-dimethoxyflavone (3), apigenin (4) and acacetin (5) based on their spectral analysis. Compounds 2, 3, 4 and 5 showed significant anti-influenza viruses activities. Compared with ribavirin, EFMS appeared to have similar efficacy against influenza viruses, was considered to be less toxic and may warrant further evaluation as a possible agent for the treatment of influenza.  相似文献   

Resveratrol Downregulates Cyp2e1 and Attenuates Chemically Induced Hepatocarcinogenesis in SD Rats     

Xiongfei Wu  Chenggang Li  Guozhen Xing  Xinming Qi  Jin Ren 《Journal of toxicologic pathology》2013,26(4):385-392

Cyp2e1 plays an important role in chemically induced hepatocarcinogenesis. Resveratrol (REV) is known to prevent diethylnitrosamine (DEN)-induced hepatocarcinogenesis, but its effects on this process induced by DEN and 2-acetylaminofluorene (2-AAF) and the role of Cyp2e1 remain unclear. In this study, glutathione S-transferase placental form (GST-P)-positive foci were used as a marker of hepatocarcinogenesis. REV or diallyl disulfide (DADS, an inhibitor of Cyp2e1) significantly reduced both the area and number of GST-P-positive foci induced by DEN and 2-AAF. Treatment with REV or DADS also markedly decreased the expression of Cyp2e1 in the rat liver. By immunohistochemical staining of serial liver sections, we found that the expression of Cyp2e1 in GST-P-positive foci showed three distinct patterns: decreased in GST-P foci, increased in GST-P foci when compared with surrounding liver tissue and mixed type. The number of GST-P foci with increased Cyp2e1 expression was greater than the number of GST-P foci with decreased Cyp2e1. Protein levels of GST-P and Cyp2e1 were also higher in foci compared with surrounding liver tissue. REV or DADS significantly reduced the expression of GST-P and Cyp2e1 in both foci and surrounding liver tissue. Taken together, these results suggested that REV has a significant inhibitory effect on chemically induced hepatocarcinogenesis, which may be attributed to downregulation of Cyp2e1.  相似文献   

植被恢复治理水土流失初探   总被引：3，自引：0，他引：3  

吴瑞娟  金卫根 《安徽农业科学》2008,36(2):675-676

江西是个多山地区,由于地质构造、暴雨等自然因素和乱砍滥伐、无序开垦等人为因素,导致地质灾害频繁发生、水土流失十分严重。在讨论江西省水土流失基本情况的基础上,提出了治理水土流失的植被恢复的方法与技术,并分析了兴国县和笔者自行研究的治理水土流失的多种生态农业模式。  相似文献   

DT系列抗草甘膦棉花新材料的田间鉴定及筛选     

戚廷香  郭立平  吴建勇  张学贤  唐会妮  王海林  乔秀琴  张兵兵  邢朝柱 《中国棉花》2008,47(8):28-29

为筛选抗除草剂棉花材料，以前期创制的抗草甘膦棉花品系DT-1～DT-18为研究对象，在新疆阿拉尔市第一师十团试验田喷洒质量浓度4.1 g·L^－1草甘膦进行相关抗性表现调查。筛选出了高产且主要营养器官和生殖器官均抗草甘膦的材料DT-2和DT-6，为棉田杂草防除和抗除草剂棉花品种的选育提供材料；同时还筛选出具有主要营养器官高抗草甘膦但花粉敏感的材料DT-8和DT-9，这为不育新材料的利用提供了可能性。  相似文献