北方麦区小麦品种高分子量谷蛋白亚基组成及其与品质性状的关系

为了解北方麦区小麦品种的遗传多样性,挖掘可供利用的优异高分子量谷蛋白亚基(HMW-GS)类型,为品质改良提供基础材料,利用聚丙烯酰胺凝胶电泳方法(SDS-PAGE),分析了172份北方麦区部分小麦品种的HMW-GS组成,并对其与蛋白质含量和沉降值之间的关系进行了研究。结果表明:Glu-A1、Glu-B1和Glu-D1分别具有3种、6种和3种不同的亚基类型。亚基1、7+9和5+10在各自位点上出现的频率最高,分别达到了54.07%、48.26%和49.42%。3个位点亚基对蛋白质含量的效应可分别表示为:1≥2*Null,13+16≥14+15≥17+18≥7+87+96+8,5+102+124+12;对沉降值的作用可分别表示为:2*≥1Null,14+15≥17+187+8≥13+167+96+8,5+102+124+12。亚基组成类型共有24种,在蛋白质含量水平上,亚基组成1/14+15/5+10、1/14+15/2+12、1/7+8/5+10、1/17+18/5+10和1/7+9/5+10相对较高;在沉降值水平上,亚基组成1/14+15/5+10、1/17+18/5+10、1/7+8/5+10、2*/7+9/5+10和1/14+15/2+12相对较高。综上所述,在24种亚基组成类型中没有发现明显优势的组合类型,优质亚基2*、17+18和14+15出现的频率较低。江苏省中筋和弱筋小麦品种选育,应结合蛋白质含量、沉降值和亚基组成进行改良。     

Adding large woody material into a headwater stream has immediate benefits for macroinvertebrate community structure and function

1. Hydromorphological rehabilitation through installing large woody material (LWM) is increasingly being used to reverse degradation of stream ecosystems. There have been many criticisms of stream rehabilitation projects, because many have not met their goals and many others have not been monitored well enough to assess whether their goals were met.
2. In a before–after–control design (with samples collected 1 year before and two successive years after LWM installation), instream biotopes and their macroinvertebrate assemblages were used as structural and functional units to assess the effectiveness of LWM installed at the Rolleston Brook, a headwater tributary of the River Welland in Leicestershire, UK.
3. The project was successful in enhancing the coefficient of variation of channel water depth and width, wetted surface area, number of instream biotopes, and the biotope diversity in the rehabilitated reach.
4. LWM installation led to significant increases in macroinvertebrate total density, total biomass, and taxon richness. Macroinvertebrate community composition was also enhanced, so that it became more similar to that of the control reach.
5. Small increases in the number of instream biotopes (appearance of gravel and leaf litter) and changes in biotope proportions (decreasing percentage of silt) were significantly related to changes in the macroinvertebrate community metrics in the rehabilitated reach.
6. The results show that using macroinvertebrate community composition is more effective than only using taxon richness and/or diversity metrics for understanding the relationship between LWM installation and macroinvertebrate community responses. To be effective, samples must also be collected in a predefined sampling protocol stratified at the instream biotope level. This approach would be of great benefit in evaluating biodiversity conservation value, and could be incorporated into the advice provided by Natural England concerning restoration and protection of English rivers that are designated as Sites of Special Scientific Interest under UK legislation or Special Areas of Conservation under European legislation.

     

家具用聚氨酯仿木材料中木粉的分散性研究

研究聚氨酯仿木材料生产用填料——木粉的添加量与粒度分别对体系黏度和沉降行为的影响等。结果表明,在m(木粉)∶m(主体聚醚)=7∶100左右、木粉粒度80～100目时,聚氨酯组合聚醚体系的黏度适中;随着木粉添加量的增加,或木粉粒度的变大,即木粉尺寸变小,木粉沉降速度下降。     

Relationship between electrophoretic pattern of storage proteins and gluten strength in durum wheat landraces from Turkey

A collection of 180 Triticum durum lines from Turkey and 22 Italian cultivars were investigated by electrophoretic techniques and evaluated for grain parameters such as protein content and sodium dodecyl sulphate (SDS)-sedimentation test. A total of 14 different patterns were observed for high-molecular-weight (HMW) glutenin subunits resulting from the combination of three alleles from the A genome and seven from the B genome. Three new allelic variants, one at Glu-A1 and two at Glu-B1, were found. Five different alleles were detected at the Glu-B1 locus. Genotypes with the same allelic variant at Gli-B1 showed inconsistency of composition in B group of low-molecular-weight (LMW) glutenin subunits. A total of 11 different B-subunit patterns were identified in the material analysed. A substantial proportion (78%) of the variation in gluten properties could be explained in terms of protein composition, with the LMW glutenin subunits making the largest contribution (54%). Results indicate that, in addition to Glu-B3 encoded proteins, variation at other loci coding for some intermediate and fastest B subunits might also influence rheological properties.     

风浪扰动引起湖泊底泥磷释放的模拟实验研究

为研究湖泊沉积物在不同风浪扰动情况下对水体中各形态磷的变化的影响,进行了室内模拟风浪扰动实验。结果表明,水体中总磷(TP)的含量随着扰动频率的增加而升高。在水体其他各形态磷中,溶解性总磷(DTP)、溶解性有机磷(DOP)的含量在模拟风速大于10~12 m/s时保持稳定,并呈下降趋势。溶解性活性磷(SRP)的含量在模拟风速大于8~10 m/s时保持稳定,并随着扰动频率的增加略下降。颗粒磷(PP)的含量随着扰动频率的增加而增加。PP为上覆水中主要形态的磷,占上覆水磷总量的54.55%~67.09%,SRP仅占上覆水磷总量的1.94%~3.19%,PP占TP的百分比随着模拟风速的升高逐渐升高,而DTP,SRP和DOP占TP的百分比随着模拟风速的升高逐渐降低。水体中颗粒物分形维数随着扰动频率的升高呈现先增大后降低的趋势。在模拟风速5~7 m/s时水体中各形态磷的含量出现激增。实验结果表明随着风浪扰动的加强能引起浅水湖泊中颗粒态和溶解态磷的浓度的迅速提高,但是由于水中颗粒物的絮凝作用的加强,悬浮颗粒物对磷的吸附能力也相应提高,因此高频风浪扰动后水体溶解性磷浓度的增幅并不明显,而仅是对浮游生物生长贡献不大的PP增幅明显。     

微灌用沉沙池泥沙沉降计算方法试验研究

对沉沙池设计中最常用的准静水沉降法和一维流超饱和输沙法进行了比较研究,得到了该两种方法用于微灌沉沙池设计中的参数变化范围,并对其中的紊动修正系数K和恢复饱和系数a进行了专门试验研究,得出了K和a的计算公式和适用条件.试验结果表明:准静水沉降法的计算误差较大,但在一定范围内,可以满足精度要求,用来估算沉沙池池长;一维流超饱和输沙法计算简单并且具有较好的计算精度,可以用于微灌用沉沙池的工程设计计算.     

Soil particle size range correction for improved calibration relationship between the laser-diffraction method and sieve-pipette method

Particle size fraction(clay, silt, and sand) is an important characteristic that influences several soil functions. The laser-diffraction method(LDM) provides a fast and cost-effective measurement of particle size distribution, but the results usually differ from those obtained by the traditional sieve-pipette method(SPM). This difference can persist even when calibration is applied between the two methods. This partly relates to the different size ranges of particles measured by the two methods as a result of different operational principles, i.e., particle sedimentation according to Stokes’ Law vs. Mie theory for laser beam scattering. The objective of this study was to identify particle size ranges of LDM equivalent to those measured by SPM and evaluate whether new calibration models based on size range correction can be used to improve LDM-estimated particle size fractions, using 51 soil samples with various texture collected from five soil orders in New Zealand. Particle size distribution was determined using both LDM and SPM. Compared with SPM, original data from LDM underestimated the clay fraction(< 2 μm), overestimated the silt fraction(2–53 μm), but provided a good estimation of the sand fraction(53–2 000 μm).Results from three statistical indices, including Pearson’s correlation coefficient, slope, and Lin’s concordance correlation coefficient, showed that the size ranges of < 2 and 2–53 μm defined by SPM corresponded with the < 5 and 5–53 μm size ranges by LDM, respectively. Compared with the traditional calibration(based on the same particle size ranges), new calibration models(based on the corrected size ranges of these two methods) improved the estimation of clay and silt contents by LDM. Compared with soil-specific models(i.e., different models were developed for different soils), a universal model may be more parsimonious for estimating particle size fractions if the samples to be assessed represent multiple soil orders.     

小麦三个品质性状微量检测方法的应用与评价

为探讨小麦育种中简单、可行和高效的品质选择指标,给小麦品质改良提供借鉴,对蛋白质含量、籽粒硬度和SDS沉淀值在本单位育种中的应用效果进行分析,结果表明籽粒硬度在不同基因型间的变异系数最大,在不同栽培条件和不同年份表现稳定,是有效、可靠的选择指标;SDS沉淀值与蛋白质含量、籽粒硬度均呈极显著正相关,在基因型间的变异较大,可作为一个能反映总体品质水平的选择指标;蛋白质含量在基因型间变异系数小,受环境影响大,用于早代选择效果不理想。品质育种中可根据籽粒硬度和SDS沉淀值进行初步选择。     

植被对南方红壤丘陵区土壤侵蚀的影响研究

本文以南方红壤区为研究对象,以传统径流小区观测为主要手段,共布设8个径流小区,每个径流小区设置不同的植被类型和植被盖度。本试验观测了36场次降雨条件下降雨量、径流量和泥沙量资料,分析了植被类型和植被盖度对减流减沙的作用规律,结果表明:①在减流作用中,乔灌木林混交林纯林;②林分结构越复杂,减沙效果越显著;③植被类型对减流减沙具有整体效果,而植被盖度更突出在影响其变化幅度上。     

普通小麦籽粒品质性状研究 Ⅱ.籽粒品质性状与农艺性状的相关

利用35个美国小麦品种×中国小麦品种组合的 F_1及其亲本,和2个组合的 F_2群体,研究了普通小麦一些籽粒品质性状及农艺性状间的相关。结果表明:(1)F_1的籽粒蛋白质含量,湿面筋含量和干面筋含量与其双亲相应性状的中亲值和低亲值均呈显著正相关;F_1的 SDS 沉淀值与双亲该性状的中亲值呈显著的正相关,与高亲值和低亲值无显著相关;(2)籽粒蛋白质含量与产量性状呈显著负相关或相关不显著。单株蛋白质产量与产量性状呈显著的正相关,SDS 沉淀值与产量性状,籽粒蛋白质含量以及湿、干面筋含量相关不显著。SDS 沉淀值及单粒蛋白质重量可作为杂种后代的选择指标。