水稻根部蛋白质组样品制备的方法研究

为了选择适用于水稻根部蛋白质组分析的样品制备方法,以水稻苗期幼嫩根尖为材料,采用TCA/丙酮沉淀法、Tris法、尿素/硫脲法对水稻根部总蛋白质进行提取并比对,通过Bradford法、SDS PAGE电泳技术对蛋白质含量和种类进行分析。结果显示,Tris法提取出的水稻根部蛋白质含量和种类明显少于其他2种方法;尿素/硫脲法和TCA/丙酮沉淀法提取的蛋白质种类和含量都较多,其中,尿素/硫脲法的蛋白质图谱中蛋白条带多,染色深而且很清晰,尤其适用于较低分子量蛋白质的提取,TCA/丙酮沉淀法则适于高分子量蛋白质的提取。因此,进行水稻根部总蛋白质组分析时,可选用尿素/硫脲法。     

单季稻通气式栽培法不同耕作方式对比试验初报

为配合水稻通气式强化栽培技术的推广,进一步了解不同耕作方式下水稻通气式栽培法的增产效应,2007年在开化县进行了单季稻不同耕作方式大区对比试验.结果表明:在水利条件较好、土壤特性为砂质壤土且肥力条件较好的田块适合采用免耕栽培法;一般情况下适宜采用水耕垄畦栽培法;旱耕法栽培产量和效益虽好,然在实际耕作过程中难以推广运用.     

Dichromate Digestion–Spectrophotometric Procedure for Determination of Soil Microbial Biomass Carbon in Association with Fumigation–Extraction

A dichromate digestion and spectrophotometric procedure is proposed for estimating soil microbial biomass carbon (C) in association with fumigation–extraction. The recommended procedure uses a volume (1.6 ml) of 0.5 M potassium sulfate (K₂SO₄) soil extracts and oxidant solution (dichromate–sulfuric acid, 2.4 mL), mixed with a volume (4 mL) for digestion at 140 °C for 30 min. The digested solution is then directly read for absorbance at 350 nm using a spectrophotometer, and the C in the digested soil extracts is measured against glucose standards. The K_EC (indicating the extractable part of microbial biomass C after fumigation) value is estimated as 0.33 for the proposed method. There are good correlations between soil microbial biomass C measured by the proposed method, the dichromate digestion titration, and oven oxidation by total organic C (TOC) analytical method. This method is a simple, rapid, and economical procedure associated with fumigation–extraction for biomass C analysis.     

双杂吨粮生理生态指标及栽培模式研究

本研究通过3年的调查与试验,阐明了不同生育期杂交稻组合在不同栽培季节,不同栽培水平下的产量形成特点及氮钾吸收特性,明确了杂交稻的穗型与生育期有一定的关系,对杂交稻需钾量是否近似常规稻这一理论问题也给予了肯定的证明.根据研究结果,提出了不同生育期杂交稻组合亩产吨粮的产量结构指标,氮钾吸收量指标及相应的生理生态指标,制订的“双季杂交水稻高产栽培模式”,实用性强,增产节支,为吨粮田的建设与推广提供了技术方案.     

Soil properties in organic olive groves compared with that in natural areas in a mountainous landscape in southern Spain

This study evaluates soil properties in organically managed olive groves and natural zones in a mountainous area of Andalusia, Spain. Two soil types (Eutric Regosol and Eutric Cambisol) and the most common soil management methods (tillage and two intensities of grazing) were studied. Both soil types in the groves had values not much lower than those in the natural areas. Average (±SE) values in the groves were 1.58 ± 0.71% for organic carbon, 323 ± 98 g kg^?1 for macroaggregate stability, 1.11 ± 0.16 g cm^?3 for bulk density, 3.5 ± 1.6 mm h^?1 for saturated hydraulic conductivity and 1209 ± 716 mg CO₂ kg^?1 for soil respiration. Overall, these values tended to be lower in the tilled compared with that in the grazed groves. The average phosphorus soil content (5.83 ± 5.22 mg kg^?1) was low for olive production and within adequate ranges for N (0.12 ± 0.05%) and K (142 ± 81 mg kg^?1). Soil erosion was high in the tilled groves (35.5 ± 18.2 t ha^?1 year^?1) with soil loss correlating with indicators of soil degradation such as organic carbon content and water stable macroaggregates. In the grazed groves, soil loss was moderate with no clear indications of soil degradation. Overall, there was significant farm‐to‐farm variability within the same soil and land management systems. Olive production had a moderate effect on soil degradation compared with natural areas and olive cultivation could be sustained in future if cover crop soil management replaced tillage, especially in the most sloping areas.