扩展青霉基因组DNA五种提取方法比较

为寻找一种适合于扩展青霉基因组DNA的提取方法,比较了固体培养、液体静置培养和液体振荡培养3种培养方式的提取效果,分别采用氯化苄法、蜗牛酶法、CTAB法、SDS法及异硫氰酸胍法提取扩展青霉菌基因组DNA,经DNA质量浓度测定及电泳分析,比较5种方法的差异,并利用扩展青霉的多聚半乳糖醛酸酶(Polygalacturonase)基因内一段保守序列,设计PCR引物,扩增大小为288 bp的特异目的基因,检测其灵敏性.结果表明:固体培养的方式较适合扩展青霉基因组DNA的提取,另外5种提取方法均能提取出扩展青霉菌基因组DNA,扩增出目的条带,其中氯化苄法和蜗牛酶法所提DNA的纯度均较好,但蜗牛酶法所提DNA量较少.因此,氯化苄法是5种提取方法中最可靠的DNA提取方法,所提DNA浓度高、纯度好、结果稳定,可作为PCR反应的模板进行特异性扩增,且该方法的最低检测限大约为1.01×10-1μg/mL.     

陕西省水库泥沙淤积灾害及其防治对策

陕西省水库泥沙淤积灾害十分严重，泥沙淤积不仅降低了水库的兴利效益，甚至危及下游人民生命、财产安全，该系统地阐述了水库泥沙淤积的危害性，成因及防治对策。     

岩溶区坡面土壤侵蚀特征研究

以重庆南川岩溶区为例,用137C s法研究了岩溶区坡面土壤侵蚀特征。结果表明,坡面上部侵蚀速率较小,平均侵蚀速率为400.8 t/(km2.a),最大侵蚀速率为1 138.4 t/(km2.a);坡面中部侵蚀加剧,平均侵蚀速率2 264.8 t/(km2.a),最大侵蚀速率可达3 760 t/(km2.a);坡面下部侵蚀减弱甚至堆积。土壤表层有机质、表层粘粒及水稳性团聚体含量在坡面上的变化与土壤侵蚀速率具有负相关趋势。     

Rainfall variability and its influence on surface flow regimes examples from the central highlands of Ethiopia

The article shows results of an international and interdisciplinary project with the title ‘Rainfall and its Erosivity in Ethiopia’. Rainfall variability affects the water resource management of Ethiopia. The influence of rainfall variability on flow regimes was investigated using five gauging stations with data availability from 1982–1997. It was confirmed that the variability in rainfall has a direct implication for surface runoff. Surface runoff declined at most of the gauging stations investigated. Therefore, effective water resource management is recommended for the study area. Future research should focus on watershed management which includes land-use and land cover. The question posed here is whether the variability in rainfall significantly affected surface flow in the study area.     

The Grain Quality of Landraces of Wheat as Compared with Modern Cultivars

Landraces of tetraploid and hexaploid wheat from the Northern Negev in Israel were evaluated over two years for their grain quality attributes. Twenty-one populations of tetraploid wheat (Triticum durum, represented by 56 accessions) and 8 populations of hexaploid wheat (T. aestivum and T. compactum, represented by 13 accessions) were compared with 3 and 4 modern improved Israeli cultivars of tetraploid and hexaploid reheat, respectively. This comparison allowed to estimate the progress made in the improvement of gram quality m present-day cultivars. Except for grain protein content in the hexaploids, significant variation was revealed among landraces in kernel weight, protein content (tetraploids), sedimentation, mixograph score and carotin content. The best modern cultivars were comparable to the best landraces in kernel weight and carotin content (tetraploids), indicating that modern wheat breeding maximized kernel weight and carotin content, as compared with the tested landraces. Gram protein content and/or quality was not maximized in modern cultivars and its improvement was deemed possible by introgression from the best landraces in this respect.     

黄土区小流域坡沟系统侵蚀与淤地坝拦蓄特征演变响应研究

通过实地调查和建立关地沟坡沟系统概化模型的有限元模拟,结合数学推导,研究坡沟系统的剩余坡长随坝地淤高的相关关系。结果表明,随着坝地淤高,坝库淤积的泥沙量与坝高和相同淤积高度下的各淤积阶段淤积泥沙量及淤积高度分别满足二项式的相关关系;相同的产沙量落淤在坝地上垂直淤积高度与坝地当前淤高满足乘幂的相关关系。     

60Co-γ射线诱变小麦品质突变体的筛选及分子标记检测

为了探索小麦品质性状的物理诱变效应,用300Gy的60Co-γ射线辐射小麦品种河科2号的干种子,对M3代234个株系的蛋白质含量、湿面筋含量、沉降值、硬度和产量性状进行变异分析和SSR分子鉴定,以超过均值±2×标准差确定变异株系.结果表明,在M3代群体中,蛋白质含量有13个株系发生正向变异,5个株系发生负向变异;湿面筋含量有8个株系发生正向变异,3个株系发生负向变异;沉降值有6个株系发生正向变异,3个株系发生负向变异;硬度有2个株系发生正向变异,9个株系发生负向变异;产量有5个株系发生正向变异,4个株系发生负向变异.相关分析表明,M3群体蛋白质含量、湿面筋含量、沉降值呈极显著正相关,表现出平行变异的趋势.初步筛选出蛋白质含量和湿面筋含量符合国家强筋小麦标准(蛋白质含量≥15％,湿面筋含量≥35％)的株系8个.经SSR分子标记检测,与控制小麦蛋白质含量的基因存在连锁的2个特异引物Xbarc164和Xgwm161在以上8个变异株系都呈现多态性标记,表明这些株系与蛋白质含量相关的基因可能发生了变异.     

2004-2011年中国主产省小麦蛋白质品质分析

 【目的】分析2004—2011年来中国主产区小麦蛋白质品质检测数据,探讨小麦蛋白质品质年度和地区间变化规律。【方法】对2004—2011年分别来自冀、鲁、豫、苏、皖5个小麦主产省的4 235份小麦样品的籽粒蛋白质含量、湿面筋含量、沉淀值、稳定时间和最大拉伸阻力进行分析。【结果】2004—2011年,中国主产省小麦籽粒蛋白质含量和湿面筋含量平均值变化不大,沉淀值呈明显下降趋势,表明近年来小麦内在品质变差;不同主产省之间小麦蛋白质含量差异较大,呈明显北高南低和东高西低趋势。【结论】近年来片面追求高产已影响了中国小麦的整体品质,致使强筋麦产区小麦面筋强度降低、弱筋麦产区小麦面筋增加。应根据各地区的不同条件发展适合本地区的高产优质小麦品种。     

Enhanced Hydrolysis of Excess Sludge by Two Surfactants

The hydrolysis efficiency of excess sludge by the two surfactants (SDS and SDBS) was investigated according to COD dissolution rate, concentrations of soluble carbohydrate and soluble protein. The results showed that the hydrolysis of excess sludge was improved by using the two surfactants. When the dosage was in low range, SCOD concentration increased significantly with dosage increasing. But the increase of SCOD was not obvious when the dosage was higher than 50 mg/g dw. SCOD concentration increased from 638.5 mg/L to 6 446.8 mg/L (SDBS) and 4 857.2 mg/L (SDS) respectively. COD dissolution rate increased from 5.8% to 37.3%(SDBS) and 30.2%(SDS) respectively. With the increase of SDS and SDBS dosage in the range of 0~150 mg/g dw, the concentrations of the soluble protein and carbohydrate increased linearly. Soluble carbohydrate increased from 3.54 mg/L to 95.56 mg/L(SDBS) and 64.20 mg/L(SDS) respectively. Soluble protein concentration increased from 11.72 mg/L to 706.30 mg/L(SDBS) and 541.08 mg/L(SDS) respectively. The concentrations of ammonia and VFA also increased with the SDS and SDBS dosage. Ammonia concentrations increased from 4.21 mg/L to 130.33 mg/L(SDBS) and 102.74 mg/L(SDS) respectively. VFA concentrations increased from 21.27 mg/L to 358.30 mg/L(SDBS) and 283.12 mg/L(SDS) respectively.