首页 <
知识图谱:全部
-
报告Primary Study of Two Oligosaccharides Inducing Resistance to Tobacco Mosaic Virus
出版时间:2007植物的诱导抗病性,又称系统获得性抗性,是植物在一定的诱抗剂刺激下,对随后的病原菌侵染具有抵抗性的特征。植物诱抗剂又名激发子,一般将能够诱导寄主防卫反应的生物来源和非生物来源的物质统称为激发子。这些物质在很低浓度下即可被植物识别为信号物质,诱发植物自身的免疫系统,最终使植物获得抵御病害的能力。寡糖类激发子是人类研究的最早、最为充分的一类激发子,并且由于其具有良好的环境相容性,因此是很有发展潜力的生物农药。壳寡糖已经应用于生产,防治作物病害,但对其进行结构修饰的寡糖,其诱抗活性还不清楚。新的寡糖—褐藻酸钠寡糖诱抗活性也未见报道。本文研究了稀土络合的壳寡糖(壳寡糖-铈配合物)以及褐藻酸钠寡糖诱导烟草抗烟草花叶病毒,为其作为生物农药提供依据。1.1.1 供试药剂 壳寡糖-铈配合物、壳寡糖,由中国科学院大连化学物理研究所研制。褐藻酸钠寡糖,由中国农业科学院饲料所研制。1.1.2 供试植物 枯斑三生烟(Nicotiana tobacum L.SamSun NN)。1.1.3 供试毒源 烟草花叶病毒(TMV),本实验室保存于普通烟上。接种病毒汁液为每克含TMV的烟草病叶,加入5倍体积0.05mol/L的磷酸缓冲液(pH7.0),在研钵中研磨后纱布过滤。1.2.1 试验处理 供试药剂:对照药剂壳寡糖50μg/ml,喷雾。供试药剂壳寡糖-铈配合物浓度分别为1μg/ml,10μg/ml,25μg/ml,50μg/ml,100μg/ml,喷雾;供试药剂褐藻酸钠寡糖浓度为25μg/ml,50μg/ml,100μg/ml,喷雾。1.2.2 试验方法 选取大小一致6~8叶期的烟草植株,叶面喷雾施药。24h后汁液摩擦接种TMV病毒。在病毒汁液中加入少量石英砂,用毛笔蘸取汁液摩接种。枯斑三生烟苗采用半叶法接种,每株接4片叶。接种后每天观察发病情况。待全面发病后,调查病斑数。重复3次。抑制率(%)=[(对照叶片病斑数-处理叶片病斑数)/对照叶片病斑数]×100%最初的试验结果表明(表1),壳寡糖-铈配合物对抑制烟草花叶病毒引起的枯斑有抑制作用。在1~100μg/ml的浓度范围里,25μg/ml的诱抗效果最好,抑制率为55%,但是略低于阳性对照壳寡糖50μg/ml,抑制率63.9%。处理斑点数抑制率(%)壳寡糖-铈配合物1μg/ml43±18c37.025μg/ml31±13b55.050μg/ml38±18cd44.0100μg/ml42±19c37.7壳寡糖50μg/ml24±14b63.9CK68±26a—表1 壳寡糖-铈配合物不同浓度喷施对烟草花叶病毒病的防效 (P由于1μg/ml的壳寡糖-铈配合物依然有诱抗活性,并且25μg/ml的诱抗活性较好,因此将取浓度10μg/ml的壳寡糖-铈配合物,进行诱抗活性的检测试验。结果表明(表2),浓度为10μg/ml的壳寡糖-铈配合物比25μg/ml具有更好的诱抗活性,抑制病毒产生枯斑的抑制率为67.4%。但是与25μg/ml没有显著性差异。因此,10~25μg/ml的壳寡糖-铈配合物具有良好的诱抗活性,说明壳寡糖与稀土的络合物可以在低于壳寡糖的使用浓度时,依然具有较高的诱抗活性。处理斑点数抑制率(%)壳寡糖-铈配合物10μg/ml43±17c67.425μg/ml57±13cd56.750μg/ml73±22d45.0100μg/ml107±27a18.9壳寡糖50μg/ml28±13b78.7CK132±46a—表2 壳寡糖-铈配合物不同浓度喷施对烟草花叶病毒病的防效 (P在褐藻酸钠诱导抗性的试验中,试验结果表明,在25~100μg/ml的浓度范围内,褐藻酸钠具有诱抗活性,可以显著抑制病毒引起的枯斑的产生。其中浓度为50μg/ml诱导抗性效果最好,抑制率为71.8%,25μg/ml的褐藻酸钠也有较高的诱抗活性,抑制率为67.4%,均略高于壳寡糖50μg/ml(抑制率64.1%)。处理斑点数抑制率(%)褐藻酸钠25μg/ml59±27bc67.450μg/ml51±21c71.8100μg/ml74±32b59.1壳寡糖50μg/ml65±26b64.1CK181±32a—表3 褐藻酸钠不同浓度喷施对烟草花叶病毒病的防效(P多糖类化合物在自然界中分布广泛,是生命物质的重要组成成分。它不仅能够控制细胞的分化、分裂,调节细胞的生长和衰老以及维持生命有机体的正常代谢,还能够调节动植物细胞免疫以及其间信息的传递。目前,多糖作为生物激发子用于抗植物病害研究比较多,其中已报道氨基寡糖素、毛头鬼伞多糖、硫酸化的葡聚糖以及脱氧半乳聚糖[1~4]等具有诱导烟草抗烟草花叶病毒的生物活性。褐藻胶是一种来源于褐藻细胞壁的水溶性酸性多糖,主要从海带、巨藻、马尾藻等褐藻中提取得到,具有独特的结构和生物活性。褐藻胶由α-L-古罗糖醛酸和β-D-甘露糖醛酸通过1,4糖苷键连接而成的直链多糖[5]。褐藻胶还有很强的抗病毒活性,如抑制TMV,抑制程度随着褐藻胶浓度的增加而增强,且随着褐藻胶中古罗糖醛酸含量的增加而增强。电镜分析表明,TMV在培养基中呈单一分散悬浮,加入褐藻胶后则形成团聚物。团聚物的形成阻止了TMV在被感染细胞表面的脱衣壳过程,而阻止了TMV的RNA穿过细胞膜,从而防止感染[6]。但由于其凝胶性强,不容易被吸收,在应用方面收到很大的限制,将其水解为寡糖后,水溶性好,利于吸收。因此本文研究褐藻酸钠水解为褐藻酸钠寡糖后的生物活性,以期在生产实践中具有更加广泛的应用。结果发现褐藻酸钠寡糖具有良好的诱抗活性,并且好于阳性对照壳寡糖,但是其具体机理还有待于进一步的研究。近几年研究发现,稀土离子,尤其是Ce,有较广泛的抑菌作用,而且有降解有机磷的能力。壳聚糖-铈配合物对黄瓜中的硫磷农药残留有一定的降解作用,其降解产物是氨基对硫磷,基本解除了毒性[7]。研究已经发现壳寡糖能够诱导烟草抗烟草花叶病毒,本文研究了壳寡糖-铈配合物是否依然保持具有诱导抗性的活性。结果表明,壳寡糖-铈配合物尽管诱抗效果不如壳寡糖明显,但仍然具有较高的诱抗活性,至于是否有降解有机硫磷的作用,需要进一步的研究。经过化学修饰的壳寡糖-铈配合物可以改变壳寡糖的理化特征,产生新的活性,这对于加强寡糖应用的广泛性和多功能性具有重要的价值。 -
报告Evaluation of Rice Varieties Resistant to Rice Stripe Virus
出版时间:2007Rice stripe(RSV)has been known to distribute in rice areas all over the world,and it is very hard virus,transmitted by insect vectors,small brown planthopper(SBPH),Laodelphax striatellus,Fallen.Once the rice is infested,there is still no very effective measures to control,even the chemicals.The chemicals'effect is not ideal and more or less they could cause some environmental risks,so there is the common opinion in the IPM system that the rice varieties having resistance to rice stripe is one of the basic and effective measures to control this disease.In 2006 and 2007 for finding the resistant rice varieties that could be used for large scale in the field,the evaluation and screening of rice varieties were conducted in Jiaxing,Zhejiang Province.In 2006,there were 40 varieties provided for the experiement,just like Chunjiang 050,Xiushui 63,Y1,Zheda 510,Tai 03126,HZ586 and so on,and Jia 991 was set to be the control.Similar to 2006 studies,in 2007,there were 20 varieties used in 2006,and newly introduced into 17 varieties,just like Leyou 2,Jiaheyou 261,Bing 04~123,Jiashao 3.The control was still Jia 991.In 2006,the experiment was conducted in the yard of Shuangqiao Academic of Agricultural Science,Xiuzhou,Jiaxing.Last year in this plot rice was planted,and in winter no crop was planted.The water and fertilizer condition was good.The rice was seeded in 2th June,and transplanted to the field in 1st July.Randomed blocking design,and the size of every plot is 30m2,with three replications.The field management was as usual,except for no chemicals use for controlling the SBPH and RSV.In 2007,the experimental field was chose to north suburb of Jiaxing,where last year the RSV occurred hard.The experimental field condition and design were familiar with 2006,and total 111plots.Investigated Methods In 2006,after 5d from 1st July when the rice were transplanted,the investigation was conducted every 5d in field,till the diseases was stable,at that time the total rice tiller and the diseased tiller amount were recorded.Num.VarietiesDiseasepercentageinthefield(%)SSRP=0.05P=0.011Jiahe2156.03aA2Y25.33bB3Jiajing36485.24bB4Y33.9cC5Shaojing04-463.49dD6Jia991(CK)3.07eE7Yongjing04683.02efEF8Y62.88fgEFG9Tai04-42.83gFG10Xiushui032.73ghGH11Qianghu9142.73ghGH12Y102.59hiHI1336You7482.52ijHI14Xiushui092.51ijHI15ZH2512.42jkIJ16Xiushui1102.27klJK17Jingzhi202.27klJK18Y42.23lmJKL19Jia04-332.14lmnKLM20Jiahua12.11mnKLM21Xiushui632.04nLM22Jiahe2182nM23Zheda5101.99nM24Bing01-1131.74oN25R41011.69oN26Y51.59oN27Jingzhi270.94pO28Chunjiang0500.91pO29Chunjiang0510.91pO30Bing03-1230.88pO31Jiaheyou28880.87pO32Zheda5320.86pO33Y80.86pO34Y10.81pO35Ning04-450.45qP36Tai031260.44qP37HZ5860rR38Y70rR39Y90rR40JiaheyouTR0rRTable 1In 2007,after 15th May,when the seeds were seminated,the investigation was conducted periodically in seedling stage till 20th June,when the rice was transplanted,the total rice tiller and the diseased tiller amount were recorded.And in field,30th July,when the disease was stable,the same indexes were recorded.By the total rice tiller and the diseased tiller amount,the disease percentage could be got,and by DPS software the resistance of different rice varieties could be made with ANOVA method.From table 1,we could get that in 2006 the RSV occurred softly in the experimental field,the CK,Jia 991'disease percentage was just 3.07%.Shaonuo 04~46,Y3,Jiajing 3648,Y2,Jiahe 215's were higher than CK;but there were four varieties,Jiaheyou TR,Y9,Y7,HZ586,which no typical RSV was found.By ANOVA analysis,the resisstance of rice varieties were obviously different.Jiaheyou TR,Y9,Y7,HZ586,which no typical RSV was found,the resistance were the highest;the Yongjing 0468,Y6 and CK were in the same level and at P=0.01 there were no obvious difference;and Shaonuo 04~46,Y3,Jiajing 3648,Y2,Jiahe 215 resistance were weak.In 2007,in the field the RSV occurred seriously in the experimental field,the CK,Jia 991'disease percentage was 19.12%(Table 2).Disease percentage of Shi 1 and Yongjing 0468 were 27.8%and 25.65%,respectively;there were 16 varieties,for example Jia 991,the disease percentage were above 10%;and the disease percentage of HZ586,Chunjiang 051,Jiahe 218,Jiaheyou 555 and Y9 were below 2%.By ANOVA analysis,the resistance of these rice varieties were seriously different.Disease percentage of Shi 1 and Yongjing 0468 were obviously higher than CK,their resistance were weak;the disease percentage of HZ586,Chunjiang 051,Jiahe 218,Jiaheyou 555 and Y9 were far below from other variety,their resistance were high;and others resistance were in the middle level.In 2007,in the seedling field the disease percentage of Bing 04~132,Zheda532,Xiushui 09,Xiuishui 110 and Bing 05~15 were all above 5%;the disease percentage of was just 0.07%,and in the Chunjiang 051 there was no RSV found;Other varieties percentage of disease were in the middle of 5%and 0.07%(Table 2).Num.VarietiesDiseasepercentageinthefield(%)SSRP=0.05P=0.01VarietiesDiseasepercentageintheseedlingfield(%)SSRP=0.05P=0.011Shi127.8aABing04-1325.68aA2Yongjing046825.65aAZheda5325.6aA3Bing04-0819.62bBXiushui095.39aAB4Jia991(CK)19.12bBXiushui335.24abAB5Xiushui11018.5bBXiushui1104.85abcABCTable 2 Evaluation of rice varieties resistance to RSV (Jiaxing, 2007)Num.VarietiesDiseasepercentageinthefield(%)SSRP=0.05P=0.01VarietiesDiseasepercentageintheseedlingfield(%)SSRP=0.05P=0.016Bing05-1517.83bBCShi14.34abcdABCD7Bing01-11317.76bcBCJiahua14.34abcdABCD8Y517.33bcBCYongjing04684.24abcdABCDE9Jiahua116.5bcdBCBing05-154.15abcdeABCDEF10Xiushui3316.4bcdBCY53.78abcdefABCDEFG11Ning04-4516.26bcdBCBing04-083.66abcdefgABCDEFGH12Bing04-13215.75bcdBCJia991(CK)2.9bcdefghABCDEFGHI13Zheda53215.69bcdBCY22.88bcdefghABCDEFGHI14Y215.18bcdBCDBing01-1132.81bcdefghiABCDEFGHI15Shi215.06bcdBCDNing04-452.77cdefghijABCDEFGHI16Xiushui0914.99bcdBCDY12.66cdefghijABCDEFGHI17Y112.96cdeBCDEQianghu1712.52cdefghijkABCDEFGHI18Qianghu17112defCDEBing05-1142.48cdefghijkABCDEFGHI19Bing03-019.22efgDEFShi22.26defghijkBCDEFGHI20Bing04-1138.25fghEFGBing03-012.14defghijkBCDEFGHI21Jiaheyou6127.18ghiEFGHBing04-1131.69efghijkCDEFGHI22Bing03-1235.76ghijFGHJiaheyou2611.39fghijkDEFGHI23Leyou25.42ghijFGHJiaheyou6121.23ghijkDEFGHI24Jiaheyou2615.23ghijFGHBing03-1231.11hijkDEFGHI25Jiaheyou16204.76ghijFGHY71hijkEFGHI26Shaonuo04-464.36hijFGHChunjiang0500.99hijkEFGHI27Jiashao34.3hijFGHJiahe2180.94hijkFGHI28Chunjiang0503.22ijFGHLeyou20.9hijkFGHI29Y73.18ijFGHJiaheyou62230.72hijkGHI30Jiaheyou62233.1ijFGHJiaheyou5550.7hijkGHI31台031262.97ijFGHJiaheyou16200.5hijkGHI32Bing05-1142.9ijFGHY90.38hijkHI33HZ5861.83jGHHZ5860.32ijkI34Chunjiang0511.81jGHShaonuo04-460.24jkI35Jiahe2181.78jGHJiashao30.24jkI36Jiaheyou5551.53jHTai031260.07kI37Y90.94jHChunjiang0510kI续表2By ANOVA analysis,the different resistance of these rice varieties also existed.the disease percentage of Bing 04~132,Zheda532 and Xiushui 09 were higher,and their resistance were weak;the disease percentage of six varieties,Chunjiang 051,Tai 03126,HZ586,Shaonuo 04~46,Jiashao 3 and Y9,were lower,and they had comparatively high resistance.Through the rice varieties screening for resistance to rice stripe virus(RSV)in the seedlingstage and in the field in Jiaxing,in 2006 and 2007,the difference of rice varieties resistance to RSV could be found,and the resistance trends between different developmental stage and different year kept in the same trends.Chunjiang 051,Y9,Jiahe218,Jiaheyou 555,Tai 03126 and Bing 03~123,and so on,had the high resistance to RSV.Though most of the results showed that the varieties resistance behave the same in different developmental stage and different year,we also should notice that few varieties did not obey this trends,for example,Shaonuo04~46,in 2006 in the field it showed very weak resistance,but in 2007 in the seedling field it showed high resistance.This perhaps tell us that just use the index of disease percentage is not enough,and at the same time we could ignore that there is still no very clear criterion to evaluate the varieties resistance to RSV.These factors could influence our evaluation.In 2006 the RSV occurred softly in the experimental field,the CK,Jia 991 disease percentage was just 3.07%,but in 2007 the CK,Jia 991's disease percentage was 19.12%,far higher than that in 2006.That is because in 2007 we chose the field where in year before the RSV occurred seriously,and advanced the seeding date and transplanted date accordingly,which the two steps could make the optimal RSV occurring conditions.On other hands,in the same cultivated condition,the disease percentage different varieties could behave 10-folder difference,it could show us clearly that the varieties resistance could exert important role in the RSV IPM system.Research was funded by a grant from Zhejiang province Science and Technology Bureau. -
报告浅谈文化营销在当代市场营销中的作用
出版时间:2009营销学泰斗菲利浦·科特勒指出,文化因素(包括文化、亚文化和社会阶层)是影响购买决策的最基本的因素。尤其在当今市场竞争越来越激烈的环境下,文化营销作为一种强有力的营销方式正在被越来越多的企业所运用,文化对消费者的渗透力、对消费者购买心理潜移默化的影响力,在营销过程中显示出惊人的力量,使越来越多的企业正在通过文化营销的方式进行品牌传播、美誉度树立、产品营销,最终达到对消费者的文化影响,促使其在文化的认同与信奉中潜移默化地接受企业或产品的营销攻势,从而毫无抗拒地接受商品。文化营销作为一种新的营销观念是以满足消费者需求的产品同质化为前提,以文化分析为基础,以满足消费者的文化需求为目的,为实现组织的目标而营造、实施、保持的文化渗透过程。文化营销从战略意义上讲是企业为满足差异文化下产生的消费者差异需求而制定的实施强有力文化渗透的战略性营销。文化营销观倡导企业以实现社会价值为组织目标,以此来保持持续的企业源于文化需求的核心竞争力,使之与企业文化的核心价值相一致,并最终形成消费动力。随着社会经济发展水平的提高,满足消费者核心价值需求的产品趋于同质化,产品质的差异化消失,因此,产品除对消费者的功能需求满足外,产品要更加注重表达文化的吸引力,去充当消费者对文化需求的载体,突显出独特的文化价值。文化营销就是将满足消费者核心价值需求的产品作为一种影响文化的载体,满足消费者对文化的深层需求的营销过程。在营销中既要适应已经被广泛认同的目标顾客的意识形态,更要善于发现并利用文化的力量影响和激发深埋于目标顾客内心深处的意识形态,文化营销的核心就是要发现并建立一种品牌与消费者在某一意识形态上能和谐共鸣的契合点,正所谓“高山云雾长,流水叹知音”,通过成功的传播手段,最终给消费者的感受:企业了解我,品牌代表我,产品属于我。文化营销必须根植于品牌和企业文化,是借文化传递和提升品牌的内涵与价值的一种手段,其最高境界就是“随风潜入夜,润物细无声”。寻求差别优势和核心竞争能力是企业竞争中最基本策略选择,然而随着市场竞争的加剧以及企业竞争行为的理性化和消费者的日益成熟,企业之间的差异也越来越小,企业以前具有的战略优势,如自然资源、资金、技术、规模等,由于相互间的差距缩小而不再成为优势;企业在产品、价格、渠道及促销等营销层面上的竞争,也由于信息的畅通和市场机制的完善,而迅速的被模仿和借鉴,唯有根植于品牌的独特文化却无法复制,这便使我们找到了一把能够在激烈的市场竞争中杀出重围、重塑品牌价值的利剑。文化营销的本质目的在于营建企业新型文化价值链,以文化亲和力将各种利益关系群体紧密维系在一起,发挥协同效应,以增强企业整体竞争优势。文化营销是适应消费需求变化,塑造企业竞争优势,弥合文化差异的重要手段。市场营销的核心是以需求为导向,从消费者的需求出发,确定企业生产与销售。随着物质产品的极大丰富,同质产品的无限增多,消费者在多样化选择中认同的不再是产品的使用价值,而是更注重产品独特的文化价值,如产品角色的认同,社会识别等文化需求。营销过程在实物上表现为产品传递以满足需要的过程,而在内层方面,则是一种文化价值的传递和达到满意的过程。现代市场营销是物化营销和文化营销的结合,营销离不开文化。从这一角度来看,文化营销是有意识的发现、甄别、培养或创造某种价值观,激发产品的文化属性,构筑亲和力,把企业营销缔造成为文化沟通,通过与消费者及社会文化的价值共振,将各种利益关系群体紧密维系在一起,从而实现企业经营目标的营销活动。塑造差别优势是企业竞争中最基本的策略选择,在随着企业在技术上差异性的缩小、营销手段趋于雷同的情况下,企业占领市场只有依靠自身品牌所包含的文化差异,通过文化营销来实现。高品位高层次的企业文化,正成为企业生存立足和赢得市场的根本。文化营销以文化之“窗口”扬企业之美名,树企业之形象,使企业文化的价值远远高于其产品自身的价值。中国有句古话:“入境而问禁,入国而问俗,入门而问讳”,恰如其分地表达了进行市场营销前了解文化差异的重要性。地域、民族、宗教、行业等不同都会造成文化差异,对同一商品属性重要程度的评价也由于文化价值观念的差异而不一致。所以,现代企业在营销中必须重视社会文化因素,借助于文化营销,才能适应不同特色的环境,形成自身的独特优势。文化营销的作用在于感情的拉近,即把消费者与产品或企业传达的感受结合起来。比如可以通过组织小规模的经验分享交流会、介绍会,使现代社会人们所感兴趣的关注点被挖掘出来,交流会上大家互通有无,将好思路好方法拿出来与大家分享,营造一种就像大家庭一样的互助互利氛围,在大家的经验中吸取营养,得到快乐,为我所用,从而自然而然的在这种融洽的氛围中传递出对高品质生活的追求,这也正是产品所要表达的价值观念,让你在不经意间产生对产品的认同,接受了产品。第一,企业在制订营销战略目标时,应建立文化子目标,子目标包含扩大企业文化影响力或企业品牌文化的顾客感召力等。在企业细分市场时把文化变量作为一个重要的因素来考虑。第二,在每个有可能与客户接触的链接点上发挥文化营销影响力,将文化的力量渗透进营销全过程。从产品定位、市场细分、产品包装与外观设计、展示与展览、促销策划、服务、CI、VI战略到CS战略、品牌战略、公共关系等方面都注入文化因素,发挥文化影响力。第三,通过积极策划、参与各种具有文化内涵的活动,来聚集目标顾客,传递品牌的内涵与价值。第四,开展文化营销的前提是对文化的深刻领悟和对目标客户群内心世界的精确把握。避免因策划者对文化的领悟不够深入而导致的“肤浅文化”、“另类文化”等,要通过有计划地开展文化营销,既提升品牌的价值,又重新塑造品牌形象,还可以聚焦目标客户。文化环境是企业进行文化营销的前提。从文化营销的角度看,文化环境是文化对消费者欲望与行为所产生影响的具体表现。文化在不同的国家与地区具有不同的特征,并会随着时间的变化而发展。因此,对文化环境的研究要从静态与动态两方面开始,既了解目前的文化需求态势,也应该追踪其发展趋势。文化的变迁标志着人们需求的改变,必将影响企业的营销决策,并会带来新的营销机会。企业必须善于审时度势,提高应变能力,跟上流行趋势顺应文化环境的变化,才能抓住营销机会。美国管理学家戴维·A·利克斯曾说过:“大凡跨文化营销的失败,几乎都是仅仅因为忽略了文化差异基本的或微妙的理解和体会所招致的结果。”不管是国际营销还是国内营销,都要与不同民族、不同文化背景的人打交道,所以必须承认和重视文化差异的影响,通过文化营销,实现跨文化参与及融合,积极影响并引导消费需求,消除偏见,减少盲目性,与顾客、中间商和公众共同构筑沟通的桥梁,确保企业营销沟通活动的顺利进行和营销战略目标的实现。首先,企业异地营销必须重视对当地文化的研究,力求“文化适应”。通过“文化营销”创新,达到相互间的沟通和互融,消除文化障碍,实现消费认同与市场开拓。其次,企业要针对目标市场实施创新型的文化互动。这就要求在进行文化营销时不仅是被动地适应当地文化,而且主动地采用各种文化营销手段,向市场传递企业的经营思想与理念,介绍、传播新的产品与概念,示范、推广新的行为方式,从而迅速有效地将一个社会的文化特征移植到另外一个社会中去,创造新的市场。文化营销是企业对消费者文化需求的反映,其核心在于寻求为顾客所接受的价值信条作为立业之本,从而促进顾客对整个企业包括其产品的认同。因此,企业营销的不仅仅是自己的产品与服务,而且是一种观念,一种消费者需要的为企业所独有的价值理念。只有深刻地领会消费者的文化需求并实施于企业的营销及整个管理活动,才可能获得成功,这就要求企业以消费者文化为前提,构建企业文化,确保文化营销与市场变化相适应。文化营销的核心是消费者利益。文化营销的受体是消费者,最大受益者是消费者,它改变了信息传播、销售渠道、服务的方式,将营销费用降到最低。企业对营销进行引导和管理,为企业赢得更多的资源投入产品核心部分,消费者能够得到更完美的核心部分价值利益。文化营销的实施不是企业直接完成,企业提供的只是产品和企业文化,营销行为由经销商或消费者自己完成,这个过程中消费者既是产品的消费者又是产品的经营者,完成信息传播和销售服务的过程,直接参与企业产生的利润分配。因此,消费文化是“因”,企业文化是“果”,文化营销是“桥梁”,只有在消费者文化的前提下建设企业文化并强化营销,才是文化营销建树和推广的必由之路,反过来文化营销又起到统领与传播企业文化的作用,这样才使企业与内外部环境相互调适,表现出强有力的市场竞争力。消费者是企业赖以生存和发展的养分和基石。企业经营活动的核心是顾客,企业经营能否成功,关键在于企业是否赢得顾客的信任。从企业的角度而言,文化营销是企业向目标市场传递企业形象、企业文化、产品信息并与目标消费者群体建立稳固关系的载体。它通过产品设计、制造、定价、递送、服务、宣传等将自身的文化信息附加于品牌之上,形成品牌信息加以传递,事实上蕴涵着产品品质的担保及职责的承担。企业的诚信将成为文化营销成败的关键要素。可以预见的是,随着消费者对自身利益保护意识的提高,企业对经营发展的需要,国家物质文明与精神文明的不断发展,中国即将迎来一个崭新的文化营销时代。 -
报告黄瓜内生细菌对黄瓜灰霉病的生物防治研究?? 基金项目:教育部长江学者和创新团队发展计划资助项目(No.200558);杨凌农业科技开发基金项目(2004JA08)。
出版时间:2007灰霉病是保护地蔬菜栽培中危害十分严重的病害,传统的化学防治造成了严重的农药残留和环境污染。应用微生物进行生物防治能够克服上述缺点,是一种安全、有效和环保的方法。本研究旨在从黄瓜植株内分离、筛选能够抑制灰霉病的拮抗细菌,并测定拮抗菌株在不同处理下对灰霉病的防治作用。主要结果如下:通过平板对峙培养筛选出8株对黄瓜灰霉病菌具有较强拮抗作用的细菌,再对这8株菌发酵滤液的抑菌活性进行测定,选出抑制效果最好的两个菌株B12和B13,抑制率分别为84.0%和81.8%。在离体叶片上,B12、B13发酵滤液对灰霉病菌的扩展均有较强的抑制作用,抑制率分别为83.2%和81.4%。两菌株活性产物可引起病原菌菌丝扭曲,菌丝膨大成串珠状分枝,顶端膨胀后细胞壁破裂,原生质外溢,产生溶菌作用。B12、B13发酵液对于灰霉病菌孢子的萌发具有强烈的抑制作用。在孢子萌发试验中,经B12、B13发酵液处理的孢子萌发率仅分别为5.5%和8.6%,滤液对孢子萌发的抑制效果与发酵液相近。将两菌的发酵滤液置于不同的温度和pH环境下处理,当温度在100℃以下、pH值在6~9时,滤液的抑菌效果表现出较强的稳定性。在温室试验中,两菌发酵液对灰霉病有较好的预防效果,B12、B13的保护防效分别为70.5% 和68.7%,治疗防效分别为51.2%和47.8%。 -
报告Nitric Oxide and Hydrogen Peroxide Signaling in Tobacco Resistance to Tobacco Mosaic Virus Induced by Oligogalacturonic Acid
出版时间:2007Plant and fungal cells are surrounded by a cell wall rich in diverse polysaccharides and proteins.It has become apparent in recent years that the carbohydrates in the cell wall function not only to maintain cell shape and integrity,but also may serve as signals in plants(Mohnen et al.,1993).Oligogalacturonic acid(OGA),a well studied elicitor,is derived from plant cell walls(Nothnagel et al.,1983).When added to cultured plant cells,it induces an oxidative burst within minutes,releasing ROS via a pathway that involves receptor binding,activation of a G-protein,influx of Ca2+,stimulation of phospholipase C,and induction of a number of kinases(Apostol et al.,1989;Horn et al.,1989;Legendre et al.,1992;Chandra et al.,1995;Legendre et al.,1993).Purified OGAs 13 to at least 26 residues long stimulate pp34 thiophosphorylation in vitro(Philippe et al.,1995).OGAs are also involved in the induction of the jasmonate pathway during plant defense response to E.carotovora subsp.Carotovora attack(Cecilia et al.,1999).The first response observed after the addition of OGAs that is clearly involved in plant defense is the production of active oxygen species,including H2O2,and O2-.This response,termed the oxidative burst,occurs within a few minutes after the addition of OGAs to suspension-cultured soybean,tobacco,and tomato cells.Reactive oxygen species are thought to have direct(through cytotoxicity)and indirect(through signaling)roles in the plant cell death required for the HR.Reactive oxygen species induce the expression of defense related genes,and are implicated as second messengers that elicit other defense responses,including systemic acquired resistance(SAR)and the HR(Brent etal.,2001).Different elicitors are thought to activate different sets of second messengers.The two signaling events that appear to participate in the OGAs inducing plant defense include the oxidative burst and NO accumulation.Inhibitors of mammalian nitric oxide synthase reduced both OGA-induced NO ac-cumulation and NOS activity,suggesting that OGA-induced NO production occurs via a NOS-like enzyme(Hu et al.,2003). Nitric oxide(NO)is a highly reactive molecule that rapidly diffuses and permeates cell membranes.During the last few years NO has a significant role in plant resist-ance to pathogens by triggering resistance-associated cell death and by contributing to the local and systemic induction of defense genes.NO stimulates signal transduction pathways through protein ki-nases,cytosolic Ca2+mobilization and protein modification(María et al.,2004). Most of the ex-perimental data available on NO detection during plant-pathogen interactions come from studies of infections by biotrophic pathogens(María et al.,2004). Additionally,an increase in NOS activity correlated with the pathogen resistance response has been observed in resistant tobacco during TMV infection( Durner et al.,1998;Chandok et al.,2003).Here we report that OGAs induced a range of defense responses in tobacco,including oxidative burst,NO accumulation and stimulation of superoxide dismutase(SOD)activity and catalase(CAT)activity.Furthermore,we show that tobacco plant sprayed with OGAs developed a resistance against infection by tobacco mosaic virus.We also provide evidence that the defense response induced by OGAs was connected with H2O2 and NO pathway.Plants of tobacco(Nicotiana tabacum var.sam sun NN)were grown from seeds in a greenhouse and were used at the 4~6-leaf stage after 2 months in culture.The plants were kept in a growth chamber at(23±1)℃ with a photoperiod of 16 h and 70%~80%relative humidity for several days before treatments.Diphenylene iodonium(DPI),2-(N-morpholino)ethanesulfonic acid(MES),Sodium nitroprusside(SNP),catalase(CAT,from bovine liver),NG-nitro-L-arginine-methyl eater(L-NAME)and 4,5-diaminofluorescein diacetate(DAF-2 DA)were obtained from Sigma.2′,7′-dichlorofluorescin diacetate(H2DCF-DA)from Biotium.All other reagents were from Shanghai Chemical Reagent CO.,LTD,Tianjin Kermel Chemical Development Centre,or Beijing Chemical Plant.OGAs was prepared from enzymatic hydrolysis of pectin and separated with membrane according to the report(H Zhang et al.,1999).An aliquot of OGAs was dissolved in water and analyzed with a matrix-assisted laser desorption-ionization time-of-flight mass spectrometer(MALID-TOF-MS,Bruker,Germany).Tobacco mosaic virus(TMV)that came from our collection was multiplied in N.tabacum.TMV was extracted from systemic infected plants by homogenization of infected leaves in 0.05mol/LH3PO4 buffer(0.05mol/L KH2PO4,0.05 M Na2HPO4 pH 6.8)with subsequent clarification of the extract by centrifugation at 2000g for 6 min.The supernatant extract was used for mechanical inoculation.All leaves of plant were sprayed with 50μg/ml of OGAs,the control plants were sprayed with water.24h~25d after OGAs application,plants were inoculated mechanically with TMV.The lesion caused by TMV was investigated at 7d after inoculation.Results were analyzed using Duncan's multiple range test at P= 0.05.For measurements of SOD and CAT activities,tobacco leaves treated with OGAs were kept in liquid nitrogen.The enzymes in the frozen powders were extracted by adding 0.05g polyvinylpyrrolidone and 5ml 0.05mol/L sodium borate buffer at pH 8.8 and homogenized at 4℃.SOD activities were measured as described by Zhu Guanglian(Zhu Guanglian et al.,1990).CAT activity was determined using the method of Beers&Sizers(Beer et al.,1952).NO and H2O2 measurement was performed using their fluorescent indicator dye DAF-2 DA and H2DCF-DA as described previously by H.Kojima(H.Kojima et al.,1998)with slight modifications.The epidermis was peeled carefully from abaxial surface of the leaves and cut into 5-mm length.Epidermal strips were placed into Tris/KCl buffer(Tris 10 mmol/L and KCl 50mmol/L,pH 7.2)containing DAF-2 DA at a final concentration of 10μmol/L for 30min,or H2DCF-DA at 50μmol/L for 10min,at 26℃ in the dark.The epidermal sections were removed and transferred to a dish of fresh Tris/KCl buffer(without probe)to wash off excess fluorophore apart from light.Then the epidermal strips were placed in Tris/KCl buffer containing OGAs and inhibitors.Examination of peels was performed using laser scanning confocal microscopy(Leica,TCS SP2)with exciting wavelength 488 nm,emitting wavelength 505~530nm.Plants were sprayed with 0.01 and 0.1 mmol/L of sodium nitroprusside(SNP),50μg/ml of OGAs,1 mmol/L,10mmol/L and 100 mmol/L H2O2,H2O2 scavenger catalase(CAT,100unit/ml)and OGAs cotreatment,H2O2 scavenger ascorbic acid(0.1mmol/L)and OGAs cotreatment and NOS inhibitor L-NAME(1mmol/L)for 30min before OGAs respectively.The control plants were sprayed with water.In all cases,24h after OGAs and other materials applications,plants were inoculated with TMV.The lesion caused by TMV was investigated at 7d after inoculation.The effect of OGAs,SNP and H2O2 on local infection was calculated from the ratio of the number of local lesion produced on the treated leaves to that on the control leaves treated with water.The TOF-MS profiles of OGAs sample were showed in Figure 1.The mass spectrum indicated that peaks corresponding to the mass numbers of( M+ Na)+of trimer to enneamer were detected.So the sample was composed mainly of OGAs having degree of polymerization( DP)2-8.Figure 1 TOF-MS of oligochitosan sampleThe results of control effects on TMV with OGAs at different concentration(50~100μg/ml)showed that the best concentration was 50 μg/ml(data not shown).The effects of application of OGAs at different time were summarized in Table 1.It was found that tobacco leaves treated with OGAs were protected against TMV infection.When the inoculation occurred at 19d after spraying 50μg/ml OGAs on tobacco plants,the relative control effect was 53.42%.We concluded that the resistance induced by OGAs became better with the inducing time until 19d.The resistance was reduced after 19d.Dayof50μg/mlgalacturonideappliedNumberoflesioncausedbyTMVRelativecontroleffect(%)vcdsaw1d125±5814.40a?4d116±3920.55a?7d120±4217.81a10d84±3742.47ab13d97±4433.56ab16d90±3238.36ab19d68±3453.42b22d71±3451.37b25d89±3739.04bck146±51—Table 1We examined the effects of OGAs on the activity of plant resistance correlated enzymes.The results(Figure 2 and Figure 3.)indicated that OGAs increased activity of SOD and CAT compared with the H2O-treated ones.There are no distinct differences on the activity of POD and PPO of tobacco leaves treated with OGAs or water(data not shown).SOD and CAT are concerned with eliminating oxygen free radical.Within one hour,activities of CAT and SOD were induced to maximum.Figure 2 Time course of SOD activity in tobacco leaves treated by 50μg/ml OGAs or H2O as CKFigure 3 Time course of CAT activity in tobacco leaves treated by 50μg/ml OGAs or H2O as CKBecause of activity of SOD and CAT induced by OGAs and the two enzymes correlative with oxygen free radical,we examined the production of H2O2 induced by OGAs.To study the effects of OGAs on the production of H2O2 in tobacco cells,the H2O2-sensitive fluorophore H2DCF-DA were used.The results of production of H2O2 in epidermal cells of tobacco leaves induced by OGAs were shown in Figure 4.It was found that OGAs caused an increase of intracellular H2DCF-DA fluorescence in epidermal cells and guard cells of tobacco leaves,indicating the production of H2O2.Fluorescence became visible along the plasma membrane and in organelles in the epidermal cells of tobacco leaves treated with OGAs(Figure 4C),but the fluorescence was very faint in the epidermal cells only loaded with H2DCF-DA(Figure 4A).The Figure 4E and G showed that CAT and DPI could inhibit the level of H2DCF-DA fluorescence in the cells of tobacco leaves treated with OGAs.The results revealed that CAT and DPI could suppress the production of H2O2.Figure 4 Laser scanning confocal microscopy of OGA-induced production of H2O2 in epidermal cells of tobacco leaves. (A) The cells loaded with H2DCF-DA. (B) Bright field image of the cells loaded with H2DCF-DA. (C) The cells loaded with H2DCF-DA before treatment with OGA. (D)Bright field image of the cells loaded with H2DCF-DA before treatment with OGA. (E) The cells loaded with H2DCF-DA and elicited by OGA in the presence of the CAT. (F) Bright field image of the cells loaded with H2DCF-DA and elicited by OGA in the presence of the CAT. (G) The cells loaded with H2DCF-DA and elicited by OGA in the presence of the DPI. (H) Bright field image of the cells loaded with H2DCF-DA and elicited by OGA in the presence of the DPI.The NO-sensitive fluorophore DAF-2DA was used to observe NO accumulation.The observed LSCM results of OGAs-induced production of NO in epidermal cells of tobacco leaves were shown in Figure 5.It was found that OGAs could enhance the level of intracellular DAF-2DA fluorescence in epidermal cells of tobacco leaves,indicating massive production of NO.Production of NO and/or accumulation was observed in organelles and along the plasma membrane in the epidermal cells of tobacco leaves treated with OGAs(Figure 5C).However,the DAF-2DA fluorescence indicating production of NO was not observed in the epidermal cells only loaded with DAF-2DA(Figure 5A).The results also indicated that CPTIO and L-NAME could inhibit the level of H2DCF-DA fluorescence in the cells of tobacco leaves treated with OGAs(Figure 5E and G).The results representedthat CPTIO and L-NAME could suppress the production of NO.Figure 5 Laser scanning confocal microscopy of OGA-induced production of NO in epidermal cells of tobacco leaves. (A) The cells loaded with DAF-2 DA. (B) Bright field image of the cells loaded with DAF-2 DA. (C) The cells loaded with DAF-2 DA before treatment with OGA. (D) Bright field image of the cells loaded with DAF-2 DA before treatment with OGA. (E) The cells loaded with DAF-2DA and elicited by OGA in the presence of the CPTIO. (F) Bright field image of the cells loaded with DAF-2DA and elicited by OGA in the presence of the CPTIO. (G) The cells loaded with DAF-2DA and elicited by OGA in the presence of the L-NAME. (H) Bright field image of the cells loaded with DAF-2DA and elicited by OGA in the presence of the L-NAME.As H2O2 and NO appear to be a key factor associated with plant induced defense disease,it was interesting to test the effect of exogenous NO and H2O2.The effect of OGAs,NO donor SNP and H2O2 at different concentrations and some scavengers are summarized in Figure 6.It was found that treatment with OGAs,SNP and H2O2 protected tobacco leaves against TMV local infection.The least lesion was observed at the treatment of 50μg/ml OGAs among the all treatments.The inhibition effect of H2O2 showed dependence on the amount of H2O2.The lesion of co-treatment of OGAs and the H2O2 scavenger CAT or ascorbic acid on TMV infection was as high as CK.We also observed SNP inducing resistance was dose-dependent.When the tobacco plants were treated with L-NAME before OGAs,the induced resistance was depressed.Therefore,we can presume NO and H2O2 are important factors participating in OGAs inducing resistance to TMV.Figure 6 Effect of OGAs and exogenous NO and H2O2 on disease symptomPectic oligosaccharides,produced by microbial enzymes,are well-known oligosaccharins,eliciting defence responses in diseased plants(Dumville et al.,2000).A broad spectrum of OG-induced pathogenesis-related defense responses has been reported(M.T.Esquerré-Tugayé et al.,2000).Most defense and developmental responses are induced by OGAs with a degree of polymerization(DP)between 10 and 15 galacturonic acid residues.OGAs with a DP less than 8 can also trigger defense responses in plants:they induce accumulation of protease inhibitors(T.Moloshok et al.,1992),ethylene production(S.D.Simpson et al.,1998)and elicitation of genes involved in jasmonic acid metabolism in tomato(C.Norman et al.,1999).In this report,we observed the OGAs with a DP between 2~8 could induce tobacco resistance to TMV.The concentration of OGAs used was also discussed.OGAs-induced plant growth has been reported(LoSchiavo et al.,1991;Filippini et al.,1992),and the maximal effect to growth was about 10-4 M(Stephen et al.,1993).To elicit plant defense responses,OGAs concentration higher than those usually required for control developmental process.In our experiments,50μg/ml was the best concentration to induce resistance within 100μg/ml(data not shown).It showed the efficiency of the OGAs in inhibition of virus infection was not depended on the dose of OGAs.But the inhibition effect was dependent on the treatment time.We observed the inducing effect of resistance to TMV was gradually elevated before 19d,but the mechanism of this needed further study.Research showed that lag period of the induced resistance of glucohexaose was about 7days and the protection period was about 28 days(Li Hongxia et al.,2005).Furthermore,tobacco plants treated by sulfated fucan or linear β-1,3 glucan showed resistance to TMV or bacterium E.carotovora after 5 days(Olivier Klarzynski et al.,2003;2000).So far no oligosaccharides were reported to have so long time inducing effect.Therefore,OGAs have more predominance to be applied in agriculture.Experimental results also showed that NO and H2O2 played important roles in OGAs inducing tobacco resistance to TMV.NO and H2O2 as important signaling active molecules in pathogen defense reaction has been extensively studied(Levine et al.,1994;Mehdy et al.,1996;Baker et al.,1995;Jabs et al.,1996;Delledonne et al.,1998;Rout-Mayer et al.,1997?;Binet et al.,1998).First,we examine the activity of plant resistance correlated enzymes.Because the activity of PAL has been confirmed elevated by many reports(Messiaen et al.,1994;Lapous et al.,1998;Dixon et al.,1989;Tepper et al.,1990),we just mensurated the PPO,POD,SOD and CAT.This includes the activity of SOD and CAT elevated,so we estimated the extra H2O2 production.To evaluate the stimulatory effect of OGAs on tobacco cells,we measured the production of H2O2 and NO in tobacco cells.The data indicated that OGAs induced the production of H2O2 and NO in epidermal cells of tobacco within a short time.These results were in agreement with the reports by Xiangyang Hu,who claimed OGAs stimulated NO accumulation in the growth medium of ginseng suspension cultures(Hu et al.,2003).Rout-Mayer and Binet discovered respectively H2O2 production within a few minutes after the addition of OGAs to suspension-cultured tobacco cells(Rout-Mayer et al.,1997;Binet et al.,1998).Many reports show H2O2 and NO exist are correlated to plant defense.H2O2 is involved in the induction and/or execution of hypersensitive reaction(C.S.Bestwick et al.,1997).H2O2 is required for the cross-linking of plant cell wall components as a part of the structural defense response(C.Lamb et al.,1997).The production of H2O2 may also lead to the development of an antimicrobial environment within the apoplast(M.Peng et al.,1992).In many cases,H2O2 collaborate with NO to execute invading pathogens.H2O2 and NO production were induced almost at the same time by cryptogein,a fungal elicitor(Foissner et al.,2000).NOS inhibitors compromise the hypersensitive resistance response in Arabidposis and tobacco(Delledonne et al.,1998?;Huang et al.,1998).TMV infection could elevate NOS(nitric oxide synthase)activity,and NO could induce PR-1 expression(Durner et al.,1998).NO,as well as other ROS,have been shown to stimulate the accumulation of SA(Durner et al.,1999),which play a critical signaling role in the activation of plant defense responses after pathogen attack.Furthermore,to test whether OGAs functions on inducing resistance in tobacco via NO and H2O2 pathway,we examined the effects of OGAs,exogenous NO donor SNP and H2O2 on inducing resistance to TMV.It was found that all of these treatments reduced lesion caused by TMV.But co-treatment with OGAs and H2O2 scavenger CAT or ascorbic acid blocked the inducing resistance.The tobacco plants inhibited NOS activity by L-NAME were not induced resistance by OGAs.So the defense response induced by OGAs was connected with NO and H2O2 pathway.The study reported herein reveals that OGAs can induce the production of H2O2 and NO,and induce the defense response against TMV.Our understanding of OGAs induced resistance is sketchy.The mechanisms of OGAs eliciting defense responses of tobacco need further investigation. -
报告Optimization of Liquid Fermentation Conditions of Bacillus subtilis Xi-55
出版时间:2007枯草芽孢杆菌(Bacillus subtilis)是土壤和植物微生态的优势种群,内生芽孢,抗逆能力强,繁殖速度快,营养要求简单,对农作物安全。作为植物根际有益微生物,通过分泌抗生物质和生长竞争,在防治植物病害方面发挥多种有益作用[1]。剂型以活体芽孢为主,田间施用可以较长时间的发挥抑制病菌作用[2~3]。枯草芽孢杆菌Xi-55是本课题组从水稻植株上分离、筛选出来的一株活性较强的生防菌株,研究发现对多种植物病原菌具有良好的防治作用[4]。芽孢杆菌的发酵培养是工业化大规模生产芽孢杆菌制剂的前提。本文对所筛选出的枯草芽孢杆菌的发酵条件进行优化,进行20L发酵罐的放大培养研究,以提高其发酵水平,为芽孢杆菌制剂的工业化生产提供参考依据。1.1.1 供试菌株 枯草芽孢杆菌Xi-55,四川省农业科学院植物保护研究所分离获得。1.1.2 培养基 斜面培养基(LB培养基):酵母膏5g,蛋白胨10g,NaCl 10g,琼脂15g,蒸馏水1000ml,pH值7.0。种子培养基(BPY培养基):牛肉膏5g,蛋白胨10g,NaCl 5g,酵母膏 5g,葡萄糖 5g,蒸馏水1000ml,pH值7.0。基础发酵培养基(KB培养基):蛋白胨 20g,甘油 10ml,K2HPO4 1.5g,MgSO4·7H2O 1.5g,蒸馏水1000ml,pH值7.0。1.2.1 培养方法 将保存在斜面上的菌种用接种环以划线形式接入LB平板上,28℃恒温培养24h活化。将活化的菌株接入装有100ml种子培养基的250ml三角瓶中,在28℃,180rpm条件下,振荡培养36~48h,制备液体种。按1%的接种量接入发酵培养基(100ml/250ml三角瓶),摇床振荡培养,测定发酵菌数量。1.2.2 生长量的测定 采用平板菌落记数法。培养液用10倍梯度稀释法稀释6~7个梯度(101,102,103,……,107)后,选择3个稀释度较高的梯度稀释液,分别吸取50μl在LB平板上,然后用灭菌的L形玻棒将菌液涂匀,每梯度重复3次。28℃恒温培养24~36h后,调查平板上的菌落数,然后计算活菌数(cfu/ml)[5]。1.2.3 培养基的优化 采用正交表L9(34)[6],四因素三水平安排试验。1.2.4 发酵条件的优化 采用优化培养基通过单因子试验,测定不同时间、温度、初始pH值、接种量和装液量对发酵菌数的影响。1.2.5 扩大培养 采用德国产Biostat C 20L全自动液体发酵罐,配制发酵培养基10L,添加消泡剂CXX-910 0.5‰。种子培养及接种量均同摇瓶试验。发酵技术参数设为:发酵温度28℃±0.5℃,通气量10L/min,搅拌转速180rpm,溶氧控制设定为以通气量为主、转速为辅,罐压0.05~0.06MPa,初始pH值为7.2。每隔4h取样,测定发酵菌数和观察芽孢形成情况,同时记录罐体内pH值变化。分别以培养时间为横坐标,菌数和pH值为纵坐标,绘制枯草芽孢杆菌在发酵罐中培养的生长曲线和pH值曲线。采用L9(34)正交设计方案,分四因素三水平对Xi-55发酵培养,测定高峰期菌数,正交试验因素水平见表1,正交设计及结果见表2,极差分析见表3。结果表明:4种营养成分对其菌数影响的顺序是A>C>D>B,培养基成分优化组合为A3B2C1D3,即蛋白胨3%,甘油1.0%,K2HPO4 0.05%,MgSO4·7H2O 0.15%。试验因素Experimentalfactor水平(Level)(%)123蛋白胨(Peptone)123甘油(Glycerine)0.51.01.5K2HPO40.050.100.15MgSO4·7H2O0.050.100.15表1 培养基优化正交试验因素水平Table 1 Orthogonal experimental factor levels for medium optimization试验号Experimentalnumble水平(Level)(%)A[蛋白胨]PeptoneB[甘油]GlycerineC[K2HPO4]D[MgSO4·7H2O]菌数(Bacteriumamount)(109cfu/ml)111117.01212225.25313331.834212318.585223110.92623129.927313211.428321325.259332123.00表2 培养基优化L9(34)正交设计及结果Table 2 L9(34) orthogonal design and results for medium opitizationA[蛋白胨]PeptoneB[甘油]GlycerineC[K2HPO4]D[MgSO4·7H2O]K14.7012.3315.6113.64K213.1413.8114.068.86K319.8911.588.0615.22R15.192.237.556.36优化组合Optimization-groupA3B2C1D3因素顺序FactororderA>C>D>B表3 培养基优化L9(34)的极差分析Table 3 Range analysis of L9(34) for medium opitization2.2.1 时间对Xi-55发酵细菌数量的影响 每隔12h从摇床上取样,测定发酵液中细菌数量,绘制Xi-55生长曲线。结果显示(图1),在发酵0~12h 之间,菌体生长繁殖缓慢;12~36h 为菌体生长加速期,也为菌体繁殖高峰时期,发酵液内细菌数量明显增加;36~48h为稳定期,菌体数量基本稳定;60h以后为孢子衰亡期,活菌由于自身产生的分解物质而使菌体分解,发酵液变透明。根据该试验结果,36~48h为Xi-55适宜发酵时间。2.2.2 温度对Xi-55发酵细菌数量的影响 分别置于24℃、26℃、28℃、30℃和32℃摇瓶培养,测定不同培养温度的生长量,结果表明(图2),28℃细菌数量最高,28~30℃细菌数基本稳定,低于28℃和超过30℃菌数明显下降。所以28~30℃为Xi-55适宜发酵温度。图1 时间对发酵菌数的影响Figure 1 Effects of time on the bacteria amount图2 温度对发酵菌数的影响Figure 2 Effects of temperature on the bacteria amount2.2.3 初始pH值对Xi-55发酵细菌数量的影响 设定pH值分别为5,6,7,8,9的培养基摇瓶培养,测定细菌生长量。结果显示(图3),当pH值为7时,细菌数量最高,当pH值为 7~8时,细菌数量基本稳定;pH值低于7和超过8,菌数明显减少;且 pH值为9或5时,菌体数量急剧减少或为零,据此推断pH值高于9或低于5时,Xi-55生长可能严重受抑制甚至不能生长,有待进一步研究。所以发酵培养基的适宜初始pH值为7~8。2.2.4 接种量对Xi-55发酵菌数的影响 分别采用0.5%、1%、2%、3%、4%等5个接种量梯度摇瓶培养,测定细菌生长量,结果显示(图4),接种量在0.5%~2%范围内,菌量数随接种量的增加而增加,接种量为2%时,菌量数最高;接种量超过2%,菌数明显减少。总体上来看,菌体生长量并非随着接种量的增加而增加,而是有一个限度。所以,2%为最佳接种量。图3 初始pH值对发酵菌数的影响Figure 3 Effects of initial pH value on bacteria amount图4 接种量对发酵菌数的影响Figure 4 Effects of inoculation amount on bacteria amount2.2.5 装液量对Xi-55发酵菌数的影响 采用装液量分别为50ml/500ml、100ml/500ml、150ml/500ml、200ml/500ml锥形瓶摇床振荡培养,测定细菌生长量,试验结果表明,通过摇瓶装液量的不同来调节通气量对Xi-55发酵菌数有较大影响。一定范围内,装液量越少,则通气量越高,氧气供应越充足,那么细菌数量就越高。50ml与100ml装液量差别不明显,但从总生长量考虑,100ml/500ml锥形瓶为最佳装液量(图5)。图5 装液量对发酵菌数的影响Figure 5 Effects of pack amount on bacteria amount在摇瓶优化发酵条件的基础上,进行了20L发酵罐的扩大培养。从生长曲线(图6)可以看出,发酵罐扩大培养的发酵周期与摇瓶发酵周期基本一致。由于发酵罐的搅拌和通氧条件均优于摇瓶发酵,因此,菌体浓度和芽孢同步形成率都明显优于摇瓶发酵。36h菌体数量达到最高量,50.61×109cfu/ml;然后进入稳定期,开始大量形成芽孢,44h形成芽孢90%以上。分析pH值曲线(图6)发现,初始pH值7.2,随着菌体生长,pH值缓慢下降;对数生长期菌体迅速繁殖,pH值也急剧下降,表明菌体大量利用养分产生了酸性物质;稳定期随着芽孢逐渐形成,pH值回升,44~48h时,芽孢数量达到最大;52h以后pH值上升至7.4左右,可以看到菌体碎片,细胞自溶,表明生长和代谢受到抑制。因此,发酵终止应在52h前,最佳放罐时间应在44~48h。图6 20L发酵罐中的生长与pH值曲线Figure 6 The growth and pH curve in 20L fermentation tank从以上试验可以看出,培养基的组成和时间、温度、培养基初始pH值、接种量、通气量、摇床转速等培养条件均对菌株的生长有很大的影响。通过单因子试验和正交试验方法,确定枯草芽孢杆菌Xi-55优化培养基为:蛋白胨3%,甘油1.0%,K2HPO4 0.05%,MgSO4·7H2O 0.15%;优化发酵条件为:时间36~48h,温度28~30℃,初始pH值7~8,接种量2%,装液量100ml/500ml锥形瓶,摇床转速180~200rpm。并进行了发酵罐扩大培养,36h达到生长高峰期,最适放罐时间44~48h;此时所获得的菌体数量约为50亿个/ml,为大规模工业化发酵培养提供了有益借鉴。在发酵过程中发现,发酵液的黏度较大,很容易产生泡沫,必须用消泡剂来消除。而本试验中采用的发酵专用含硅消泡剂CXX-910对pH值有轻微影响,故添加消泡剂不宜过多。操作时可预先在培养基里添加少量消泡剂,然后通过发酵罐上的补料装置在发酵过程中自行控制补充,这样可以在满足消泡的同时尽量降低消泡剂的添加量,减少消泡剂对pH值的影响,比一次性添加或单纯通过补料装置添加效果要好。 -
报告“中二软占”空间诱变品系的抗稻瘟病研究
出版时间:2007中二软占是广东省农业科学院水稻所以粳籼21为母本,长丝占为父本杂交育成的早、晚兼用常规优质稻品种,于2001年通过广东省农作物品种审定。中二软占的丰产性和适应性好,米质良好,但中感稻瘟病。作者等将中二软占品种的种子经密封后送到酒泉卫星发射基地(部分中二软占种子留在地面作为非诱变原种对照),于2003年11月3日随“中国返回式科学试验卫星”升空,经过18天的太空旅行,于11月21日返回地面。2004年早造将中二软占诱变和非诱变原种对照单株种植,采用稻瘟病菌株GD0193接种到3到3片半叶的种苗上,发病7天后调查,792株经过空间诱变的种苗,病级为0~3级的抗病植株有208株,占总数的26.3%;病级为4~5级的植株有368株,占46.5%;病级在6级以上的有216株,占27.3%;80株原种对照种苗的病级均在6级以上。试验结果表明,中二软占的种子经过返回式卫星搭载后,对稻瘟病产生抗性变异,其中抗性明显提高的占26.3%;抗性比原种提高(病级0~5级)的植株数占72.7%。对中二软占空间诱变SP2代材料的抗性分离规律进行研究。从空间诱变中二软占SP1中选取33株抗病和2株感病植株的种子作为SP2的接种材料,原种中二软占作对照,接种稻瘟病菌株采用GD0193菌株。空间诱变中二软占SP1的2个感病植株在SP2抗性没有产生分离,33个抗病植株在SP2抗性产生分离,而且各株系抗感分离的比例也不一样。对33个抗病SP2株系抗感分离的比例进行X2分析,结果表明有21个株系抗感分离比例符合理论比值3:1,说明这21个株系可能受一个位点的抗性基因控制;有8个株系抗感分离比例符合理论比值15:1,说明这8个株系可能受两个位点的抗性基因控制。另外,有4个株系抗感分离比例既不符合3:1也不符合15:1。表明这4个株系的遗传基础比较复杂。由于目前对水稻空间诱变的染色体变异的遗传机理还不是很清楚,诱变除了导致基因的位点突变以外,也可能导致染色体的缺失、重复、倒位、易位等畸变。这些畸变将影响水稻的性状,而且使其在SP2的基因的分离规律变得更复杂。从33个空间诱变中二软占抗病植株的SP3-SP4代株系中连续两造各筛选出5株农艺经济性状较好的单株,考种及抗病性鉴定结果表明,与原种中二软占比较,抗病性有不同程度的提高,而且穗长、总粒数、结实率、粒长、谷粒长宽比、千粒重等性状与原种中二软占的相比,也有不同程度的提高。将33个空间诱变中二软占抗病植株和1个感病植株的SP4代株系进行抗谱测定,采用38个不同致病型代表菌株接种结果,原种中二软占和空间诱变感病株系的抗谱分别为29.0%和34.2%,33个空间诱变抗病株系中,抗谱达到80%以上的诱变株系有32个,其中抗谱在90%以上的诱变株系有24个,抗谱在80%~90%间的诱变株系有8个。中二软占是优质但中感稻瘟病的品种,从其空间诱变后代中有望筛选出对稻瘟病抗性及农艺经济性状比原种好的株系,可为抗稻瘟病育种提供新材料及优良抗源。目前作者等正重点开展有关优质、抗病的中二软占诱变品系的抗性遗传基础分析、抗病基因标记定位、空间诱变抗性变异机理研究等。 -
报告Identification of Pathogens Causing Brown Patch of Festuca arundinacea
出版时间:2007褐斑病又称夏枯病,是草坪上最为流行的病害之一,在世界范围内的冷、暖季草坪草中都有发生。高羊茅褐斑病的发病部位主要是叶片和茎部,病斑椭圆形或不规则形,初为水渍状,后变褐至灰白枯死,边缘红褐色。湿度大时,清晨可在病部外缘观察到大量白色菌丝形成的“烟圈”及深褐色颗粒状菌核。感病草坪草的褪色及萎陷可造成大块黄褐色或枯黄色的病斑,多个病斑合并可致使草坪草大面积枯死。从华中农业大学草坪基地高羊茅田块采集发病植株,按照常规组织分离法分离、纯化得到病原菌。致病性测定采用4mm菌丝块接种离体高羊茅叶片,28℃保湿培养2天后,叶片上可形成不规则形水渍状病斑,边缘褐色。再次分离发病叶片的病组织,可得到与接种病原菌菌丝体形态与培养性状一致的病原菌,证实该病原菌为高羊茅褐斑病的致病菌。将得到的病原菌置于PDA培养基28℃培养,生长速度较快,2天可长满直径为9cm的培养皿。菌丝初无色,2天后菌落颜色从白色到浅黄色、浅黄褐色,培养5~6天后,菌落呈褐色。菌丝体长绒毛状,较稀疏,放射分布。菌丝直径3.4~10.5μm,直角或锐角分支,分枝处明显缢缩,距分枝不远处有一分隔。通常5天后菌丝纠结形成白色菌核,颜色从浅白色到灰色、褐色或黑色,近圆形至不规则形,单生或聚生。菌核内外颜色一致。将培养1~2天的菌丝经DAPI(5μg/ml)染色后于荧光显微镜下观察为多核,平均每细胞3~15个细胞核。根据对分离物的培养特征和形态学鉴定,将引起高羊茅褐斑病的病原菌鉴定为立枯丝核菌(Rhizoctonia solani)。对该菌核糖体DNA的ITS区域进行PCR扩增,测序结果与GenBank中核酸数据库进行同源性比较。该病原菌与Rhizoctonia solani AG 1-IB的序列同源性为99%。其结果与形态学鉴定结果一致。对病原菌寄主范围测定结果表明,该病原菌除侵染高羊茅外,还可为害黑麦草、早熟禾、狗牙根。
