Herbicidal Activities of Corn Gluten Peptides Prepared by Different Proteases and Their Relations to Molecular Weight.

以碱性蛋白酶、木瓜蛋白酶、风味蛋白酶和中性蛋白酶4种蛋白酶为水解酶制备玉米蛋白水解肽,用培养皿生物分析法检测在不同浓度(0.5、1.0、2.0和5.0 mg.mL-1)下的4种玉米蛋白水解肽对光鳞水蜈蚣(Kyllingabrevitoliavar.leiolepis)种子萌发过程中根系生长的抑制活性;采用超滤法制备相对分子质量不同的肽段并比较其除草活性。结果表明:不同浓度下的4种玉米蛋白水解肽对光鳞水蜈蚣种子萌发过程中根系生长均有抑制作用,且随着水解肽浓度的增高,其对根系生长的抑制活性增强;碱性蛋白酶、木瓜蛋白酶制备的玉米蛋白粉水解肽对根系生长的抑制活性明显高于风味蛋白酶和中性蛋白酶制备的玉米蛋白粉水解肽。相对分子质量不同的玉米蛋白粉水解肽对根系生长的抑制活性存在差异,5 000 u以下的小分子肽具有更高的抑制活性。Corn gluten peptides were prepared by four different kinds of proteases and their respective root-inhibiting activities on smoothscale kyllinga(Kyllinga brevitolia var.leiolepis) were evaluated in Petri dish bioassay when they were(0.5),1.0,2.0 and 5.0 mg·mL~(-1) in concentration.Results show that they all demonstrated root-inhibiting activity,which increased with their concentration.Herbicidal activities of peptides prepared by alcalase and Papain were significantly higher than those prepared by flavourzyme and neutrase.The peptides varied in bioactivity with molecular weight.Peptides small in molecular weight(<5 000 u) exhibited higher herbicidal activity than those large in molecular weight.广东省科技发展项目(03KJ6062

A preliminary study on the herbicidal activity of the hydrolysates from five natural protein materials

以鱼粉、肉骨粉、豆粕、菜籽粕及芡粉等几种天然蛋白原料为底物,以碱性蛋白酶为水解酶制备出天然蛋白原料的水解物,用培养皿生物分析法检测不同蛋白原料水解物在不同浓度(0.5、1、2、5 mg/mL)条件下对杂草野菊种子的生根抑制活性。结果表明:不同蛋白原料制备出的水解物对野菊种子萌发根系生长均有抑制作用,并且随着浓度增加其抑制活性增强,不同蛋白原料水解物的除草活性有显著性差异,其除草活性顺序为:鱼粉水解物>肉骨粉水解物>豆粕水解物>菜籽粕水解物>芡粉水解物,水解物的根抑制活性与原料的蛋白含量及其水解物的多肽含量成正相关性,作者推测,天然蛋白水解物中的多肽可能是植物种子萌发时根系生长抑制活性物质,但这种根抑制活性究竟是由于特异性多肽的化感作用还是植物种子萌发时对高氮胁迫反应有待进一步研究。The hydrolysates of five proteins materials,namely fish meal(FM),meat and bone meal(MBM),soybean meal(SBM),rapeseed meal(RSM) and wheal gluten meal(WGM),were prepared with alcalase and their root-inhibiting activity to Indian dendranthema,Dendranthema indicum(L.) Des Moul was measured in Petri dish at different concentrations,i.e.0,0.5,1,2,5 mg/mL.All hydrolysates showed root-inhibiting activity,and their bioactivity was raised as their concentrations increased.The herbicidal activities of the five hydrolysates were significantly different from each other.The herbicidal activities declined in the following sequence: fish hydrolysate(FH),meat and bone hydrolysate(MBH),soybean hydrolysate(SBH),rapeseed hydrolysate(RSH) and wheat gluten meal(WGH).The root-inhibiting activity was positively correlated to the peptide contents of the hydrolysates and protein contents of the materials,suggesting that the peptides in the hydrolysates were herbicidal bioactive substances.However,whether the herbicidal activity is due to the allopethy of special peptides or only to the high N stress against germinating seeds remains unclear and further studies are needed.广东省科技发展项目(03KJ6062

Seasonal Variations and Cluster Analysis of the Turf Weed Communities in Shenzhen,China

用样线法调查了深圳市区不同管理类型草坪的杂草周年发生及分布情况,并用系统聚类法分析了各草坪杂草群落的发生规律。共观察到25科83种草坪杂草,其中春季发生的杂草种类67种,夏季68种,秋季70种,冬季49种,四季共有的种类40种,占总数的48.2%;香附子、光鳞水蜈蚣、狗牙根、千根草等9种杂草为优势种,也是重要的防除对象;深圳市草坪杂草全年共分为15类群落,其中春季3类,夏、秋、冬季各4类,管理水平是影响杂草群落发生特征的最直接因素。The species composition and seasonal variations of the turf weed communities were investigated in Shenzhen with line intercept method,and all the data obtained were analyzed with cluster analysis.Totally 83 species belonging to 25 families were found,of which 67,68,70 and 49 species were observed in spring,summer,autumn and winter,respectively.The species occurred in all the four seasons counted for 48.2% of the total species.Cyperus rotundus,Kylling abrevitolia var.leiolepis,Cynodon dactylon and Euphorbia thymifolia were dominant and the most dangerous weed species.The turf weeds were classified into 15 communities,of which 3 communities observed in spring while 4 communities investigated in each of the other three seasons.Management level is the most important factor affecting the weed communities' structure.广东省科技发展项目(03KJ6062

Root-inhibiting Activity of Hydrolized Peptides of Corn Gluten Meal on Smoothscale Kyllinga(Kyllinga brevitolia var.leiolepis)

以木瓜蛋白酶、中性蛋白酶为水解酶,以玉米蛋白粉为底物,制备出不同酶解时间条件下的玉米蛋白水解多肽。用培养皿生物分析法检测不同玉米蛋白水解多肽在不同浓度(0.5 mg/mL、1 mg/mL、2 mg/mL、5 mg/mL)条件下对光磷水蜈蚣(Kyllinga brevitoliavar.leiolepis)种子生根抑制活性。结果表明:①两种蛋白酶不同水解时间制备的玉米蛋白粉水解多肽对光鳞水蜈蚣种子萌发生根均有抑制作用,且随着浓度增高生根抑制活性增强;②木瓜蛋白酶在水解3 h和6 h制得玉米多肽的生根抑制活性明显优于水解9 h和12 h制得的玉米多肽,而中性蛋白酶在不同水解时间水解玉米蛋白粉所得的水解多肽对光磷水蜈蚣的抑制活性无显著性差异;③木瓜蛋白酶制备的玉米多肽比中性蛋白酶制备的玉米多肽生根抑制活性强,并达到极显著性差异水平(P<0.01)。Corn gluten peptides were prepared by two proteases in different hydrolysis times and their root-inhibiting activity on Kyllinga brevitolia var.leiolepis was conducted in petri dish bioassays at rate of 0,0.5 mg/mL,1 mg/mL,2 mg/mL,5 mg/mL.The result showed: ①Corn gluten peptides prepared by two proteases have root-inhibiting activity on Kyllinga brevitolia var.leiolepis,and their bioactivity becomes greater with the increasing concentrations.② Inhibitory activities of peptides changed with hydrolyzing time using papain to hydrolyze CGM and corn gluten peptides prepared at hydrolysis time of 3 hours and 6 hours exhibited more inhibitory activity than that of 9h and 12h.On the contrary,no difference was found for the peptides prepared by neutrase in different hydrolysis time.③ Compared with papain,peptides prepared by neutrase is less inhibitory active and the ANOVA analysis shows highly significantly difference.Therefore,as a hydrolysase,papain can be taken priority to prepare the corn gluten peptides.广东省科技发展项目(03KJ6062

Factors Influencing the Lightness of Paralic Sediments From Borehole LZ908 in the Southern Laizhou Bay

对中国北方莱州湾南岸钻孔上部54m海陆交互相沉积物的亮度进行研究;探讨其作为海陆交互相沉积物的环境指标的可行性;同时通过对比不同样品处理方式所得的亮度值探讨影响亮度的几个因素。测量分2次进行;分别使用Minolta CM-2002分光光度计针对柱状原样及Minolta CR400/410色差计针对风干研磨后的散样进行。研究结果表明;海陆交互相沉积物的亮度;尤其是经过风干处理后样品的亮度值;与碳酸钙含量及粒度两个古气候代用指标均具有显著相关关系;可以将其作为碳酸钙含量的替代指标应用于海陆交互相沉积物的环境演化研究。而亮度值与碳酸钙含量不一致性;可归因于沉积物中非碳酸钙组分的性质及含量。粒度与亮度的相关性显示;钻孔砂质沉积中含有的大量深色的有机质使得钻孔中粒度0～31μm的部分比例越高;亮度会越大;而粒度>31μm的部分比例越高;亮度会越小。2次亮度值的对比表明;水分、氧化作用及研磨是沉积物2次测量所得亮度值存在差异的主要原因

碳酸盐含量对莱州湾南岸钻孔沉积物粒度测试结果的影响

采用2种不同的前处理方法对莱州湾南岸钻孔沉积物样品进行粒度测量。通过比较沉积物粒度的粒级组成发现,未去除碳酸盐颗粒的测量结果,黏土粒级含量显著增加,粉砂粒级的变化主要受到黏土粒级含量增加的影响而降低,砂粒级未见明显的变化规律。应用2参数Weibull分布,对沉积物粒度分布进行拟合,发现测量样品的粒度分布以3峰态和4峰态为主,是否去除碳酸盐不改变粒度分布的基本形态,但对各组分的相对含量影响明显。通过实验对比,我们认为,粒度测量的前处理过程中去除碳酸盐是必要的。

中国现代花粉数据集

孢粉是重建古植被、古气候的重要基础数据。孢粉数据库对研究样点至区域和全球尺度上的古环境演变规律、古气候变化特征反演和古生物地球化学循环模拟等具有重要意义。该文收集整理了中国1960–2020年间发表和部分未发表的现代花粉数据记录,包括样品编号、采样位置、采样地经纬度和海拔高度、样品类型、数据来源、数据类型、周边植被信息、参考文献、花粉类群及其含量等信息;并对数据进行筛选和标准化等处理,由此整合为中国现代花粉数据集。该数据集由4 497个现代花粉采样点的数据信息组成,包括660个来自中国第四纪孢粉数据库数据,1 763个前期整理发表的数据和2 074个近期收集的数据,涵盖772个花粉类群。样品类型以土壤表层样品(3 332个)为主,苔藓样品以及湖泊、海洋表层样品等为辅,广泛分布于全国不同地理区域和植被类型中,其中以温带荒漠区域(24.91%)和亚热带常绿阔叶林区域(24.02%)最丰富,其次为温带草原区域(16.14%)和青藏高原高寒植被区域(15.83%)。数据按照来源可分为原始数据(58%)和数值化数据(42%);按照数据类型可分为原始统计粒数的样点(59%)和以花粉百分比表达的样点(41%)。半个多世纪以来,科研人员开展了大量的表层现代花粉取样和研究。本数据集虽然仅获取部分记录,但样点覆盖了我国绝大多数地区,可有效地用于古植被与古气候重建的现代孢粉与现代植被校验,并将为中国孢粉数据库的建立与更深入的孢粉研究提供数据支撑

中国被子植物濒危等级的评估

本文基于文献和标本信息收集以及专家提供的数据,运用IUCN濒危物种红色名录方法首次对中国范围内所有已知被子植物进行灭绝风险评估。结果显示,在评估的30,068种被子植物中,灭绝等级(含灭绝、野外灭绝、地区灭绝)共计40种;受威胁等级(极危、濒危、易危)3,363种,受威胁比例为11.18%。从空间分布看,我国受威胁被子植物主要集中分布在西南地区以及台湾、海南等岛屿,且主要分布在中低海拔地区。对受威胁物种的分析结果表明,包括原生植被破坏在内的生境丧失及破碎化是我国被子植物濒危的首要因子,涉及约84.1%的受威胁物种;过度采挖和物种内在系统问题位列致危因子的第二、三位,分别涉及38%和14%的物种。其他的致危因子包括外来入侵种在内的种间竞争、环境污染、自然灾害和全球气候变化等。一个物种的致危因子往往是多方面的。本次评估与2004年红色名录相比,生境变化、实施保护措施及分类学新修订使一些物种的濒危等级发生了变化,这也印证了红色名录是一个动态的系统,需要根据最新信息进行更新,以便为生物多样性保护提供实时准确的基础数据

中国高等植物受威胁物种名录

2008年,环境保护部和中国科学院联合启动了《中国生物多样性红色名录——高等植物卷》的编制工作。通过这项工作,我们依据IUCN濒危物种红色名录标准对中国野生高等植物的濒危状况进行了全面评估,编制了中国高等植物红色名录。2013年9月,该名录以环境保护部、中国科学院第54号公告形式发布,即《中国生物多样性红色名录—

JUNO Sensitivity on Proton Decay p→νˉK+p\to \bar\nu K^+ Searches

The Jiangmen Underground Neutrino Observatory (JUNO) is a large liquid scintillator detector designed to explore many topics in fundamental physics. In this paper, the potential on searching for proton decay in $p\to \bar\nu K^+$ mode with JUNO is investigated.The kaon and its decay particles feature a clear three-fold coincidence signature that results in a high efficiency for identification. Moreover, the excellent energy resolution of JUNO permits to suppress the sizable background caused by other delayed signals. Based on these advantages, the detection efficiency for the proton decay via $p\to \bar\nu K^+$ is 36.9% with a background level of 0.2 events after 10 years of data taking. The estimated sensitivity based on 200 kton-years exposure is $9.6 \times 10^{33}$ years, competitive with the current best limits on the proton lifetime in this channel