水稻对褐飞虱的抗性与挥发性次生物质总量的关系

运用水蒸气蒸馏法提取水稻植株的挥发性次生物质,并进行GC/MS分析,比较水稻抗、感褐飞虱植株中挥发性次生物质总量的差异.结果表明,感性植株的挥发性次生物质总量明显高于抗性植株,前者比后者高45.4%;挥发性次生物质总量随植株抗性增强而降低,1级最低,7级最高;挥发性次生物质总量随植株所含抗性基因数的增加而减少.     

6种杀虫剂对水稻褐飞虱田间种群的毒力及控制作用

2009～2010年,采用稻秆浸渍接虫法,测定了福建省3个地区的褐飞虱田间种群对6种杀虫剂的敏感性并进行抗性分析,在仙游县晚稻田褐飞虱初孵若虫始盛期,采用喷雾法对6种药剂的田间控制作用进行了研究,结果表明:同一个种群的褐飞虱若虫对同一种药剂的敏感性随着虫龄的增加而降低;烯啶虫胺对不同地理种群的褐飞虱若虫均表现出最高的毒...     

土壤类型对凉山烤烟品质的影响

以云烟87为材料,在盐源烟区选取5种不同类型土壤进行烤烟大田栽培,研究了四川凉山土壤类型对烤烟主要化学成分、中性致香物质及内在质量的影响。结果表明,参试土壤钙、镁含量较丰富,明显缺氯;紫色土、红壤、黄壤、沉积土等明显缺钾和氮;水稻土和沉积土缺磷。不同土壤烤后烟叶化学成分有差异,水稻土和紫色土上烤后烟叶烟碱、总氮含量较高,糖含量较低,基本符合优质烟叶质量标准;红壤、紫色土和黄壤上烤后烟叶钾含量相对较高,接近优质烟叶钾含量;沉积土、水稻土和红壤上烤后烟叶氯含量较高,接近优质烟叶氯含量。不同土壤烤后烟叶致香物质含量差异较大,黄壤和红壤上烤后烟叶苯丙氨酸类降解产物含量较高;黄壤、红壤和水稻土上烤后烟叶类西柏烷类产物含量较高;水稻土、紫色土和红壤上烤后烟叶质体色素降解产物含量及致香成分总量较高。不同土壤烤后烟叶内在质量存在一定的差异,由高到低对应的植烟土壤依次为:紫色土、红壤、黄壤、沉积土、水稻土。     

郏县红牛SREBP-1c基因84 bp缺失突变的检测及其对6个生长性状的影响

旨在研究牛SREBP-1c基因内含子7区域84bp缺失的遗传多态性及其对生长性状的影响。本试验以中国地方品种郏县红牛共计441头个体为实验动物,通过DNA测序技术和琼脂糖凝胶电泳方法检测该区域缺失突变的多态性。结果发现,在该突变位点检测到2种基因型:WW和WD型,等位基因W和D频率分别为0.8651和0.1349。He、Ne和PIC值都很低,说明在本突变位点遗传多态性不够丰富。该突变位点处于Hardy-Weinberg平衡状态(P0.05)。该位点的多态性与郏县红牛6个生长性状指标关联分析显示,郏县红牛WD基因型个体在12、18、24月龄的体质量和胸围显著高于WW基因型个体(P0.01或P0.05),基因型WD个体在18、24月龄的体斜长显著高于WW基因型个体(P0.05),基因型WD个体在18月龄的平均日增体质量显著高于WW基因型个体(P0.01)。初步认为WD型是提高黄牛体质量和体尺指标性状的有利基因型。本研究结果表明,黄牛SREBP-1c基因内含子7区域84bp缺失位点可作为郏县红牛生长性状的潜在分子育种标记,具有很大的研究价值。     

长壮蝎蝽假死行为的初步研究*

 对长壮蝎蝽(Laccotrephes robustusStl)成虫在水体内外的假死行为以及控制假死行为的关键部位进行了研究。结果表明：(1)水体外假死时长明显高于水体中;(2) 对不同捕食压力的适应导致蝎蝽在水体内外假死行为的差别,并能够提高自身的适合度;(3) 蝎蝽的假死行为并不完全受脑或某一神经节控制,胸部各体节均有独立完成假死动作的可能。     

“田园城市”美学思想与意境设计研究——以“成都·世界田园城市”为例

从田园城市概念产生的背景、田园城市的理论与实践、对国内外城市规划中的影响、成都建设田园城市所具备的条件这4个方面阐述了田园城市在“成都·世界田园城市”意境规划设计中的指导作用.通过对研究内容的分析,总结出田园城市理论在成都建设城市规划中的美学价值:可形成大面积的绿色视野,营造成都独特的休闲文化气息,构建田园意象、自然文化景观多样性的统一.     

Portable soil test laboratory results compared to standard soil test values

Abstract

Results from a commercially available portable soil test laboratory were compared to standard soil test procedures used by a public soil testing laboratory. Standard soil tests examined were water extracted NO₃‐N, pH, Acid‐P, NaHCO₃‐P, and ammonium acetate extracted K. Approximately 35 to 55 different soils were used to compare methods for each soil test. Linear regression equations between the portable laboratory soil test values and those from the standard procedures were developed. The r² values for NO₃‐N, pH, Acid‐P, NaHCO₃‐P, and K were 0.970, 0.891, 0.734, 0.742, and 0.887, respectively. The coefficient of variability values for NO₃‐N, pH, Acid‐P, NaHCO₃‐P, and K were 10, 1, 13, 15, and 6%, respectively for the portable laboratory, and 9, 2, 8, 9, and 5%, respectively for the public soil testing laboratory. Multiple regression was used to relate soil properties to soil test results. The R2 values for NO3‐N, pH, Acid‐P, NaHCO₃‐P, and K were 0.970, 0.911, 0.860, 0.940, and 0.936, respectively.     

Simultaneous extraction of P and K from IOWA soils with bray 1 solution containing NH4Cl

Abstract

The effects of combining the Bray 1 extracting solution with ammonium chloride (NH₄C1) for simultaneous extraction of P and K were studied in several experiments. For pooled data from the experiments in which the Bray 1 solution containing 0.5 mol L^‐1 NH₄C1 was used, the relationship between the amounts of P and K extracted by the combined solution (P_C and K_C)and the amounts extracted separately by Bray 1 (P_R) and 1 N neutral NH₄OAc (K_R) are given by P_C = 2 + 0.906 P_R, r = 0.988 and K_c = 14 + 1.033 K_R, r = 0.944. Variations were observed in different experiments when the concentration of NH₄C1 and the conditions of the experiment were varied.     

Secondary minerals from extrapedogenic per latus acidic weathering environments at geomorphic edges, Eastern Nebraska, USA

Acidic weathering of the sulfidic Upper Cretaceous Carlile and Pierre Shales in Nebraska has led to the precipitation of the Al sulfate–hydroxide minerals aluminite, alunite, “basaluminite”/felsöbányaite (e.g.,), the aluminum hydroxides gibbsite and bayerite, and the rare Al phosphate hydroxide vashegyite. Kaolinite has also been produced as a result of this acidic weathering. These minerals do not appear as neoformed constituents in any extant soils in the region, and their existence underscores the ability of pyrite oxidation to produce major changes in mineralogy on a Holocene to Recent time scale. Jarosite, hydronium jarosite, gypsum, halotrichite, and melanterite also appear as secondary minerals in the weathered shales. Acidic weathering and the formation of new minerals is extrapedogenic because it occurs well below the limit of modern soil sola. These processes also occur at the edges of major landscape elements and can be considered to have a strong lateral component processes, making them “per latus” processes in our usage.