青海弧菌Q67冻干粉急性毒性测试方法研究

[目的]研究利用青海弧菌Q67冻干粉进行急性毒性测试的方法。[方法]通过一系列试验,探讨青海弧菌Q67冻干粉复苏及与毒物反应接触时间对毒性测试的影响,筛选出适宜青海弧菌急性毒性测试的毒性参照物,在充分借鉴国际标准ISO 11348的基础上分析现行发光抑制率计算方法的不足,提出了优化的计算方法。[结果]青海弧菌Q67冻干粉复苏的30～120 min内进行毒性测试,与毒物的反应时间控制在15～20 min时,测得数据稳定、可靠。ZnCl2适合用作青海弧菌生物急性毒性测试的毒性参照物。[结论]该研究为制定青海弧菌Q67冻干粉急性毒性测试标准提供理论依据。     

石油脱硫微生物的筛选及特性研究

从泰安某加油站采集土壤样品,筛选到一株可以专一性降解二苯并噻吩(DBT)的菌株,经常规和生理生化鉴定判断为红球菌属(Rhodococcus sp.),命名为YY-5。对DBT的降解产物经分析为二羟基联苯(2-HBP)、二苯并噻砜(DBTO2)和硫酸根离子,完全符合"4S"途径。产物用gibb’s试剂结合分光光度计测试,测算出菌株的脱硫能力。脱硫试验表明,DBT浓度对菌株的脱硫能力也有影响,DBT浓度过高,会抑制菌株的脱硫能力。一般在54 h左右YY-5的酶活性开始降低,在80 h左右完成脱硫。在以正十二烷、正十六烷、液体石蜡、萘和柴油为碳源的培养基中生长不旺盛,不能利用上述烃类作唯一碳源和能源。说明YY-5在脱硫过程中不会明显降低燃油的燃烧值。另外试验也表明,有机氮对菌的脱硫活性有抑制作用。     

铜、镉胁迫对杨树叶片中防御蛋白活性的影响

为明确重金属胁迫对杨树抗性的影响,以1年生杨树扦插盆栽苗为试验材料,分析在重金属铜( Cu)、镉( Cd)胁迫下杨树叶片中防御蛋白活性的变化。分别用Cu、Cd的3种不同质量分数处理扦插盆栽苗的土壤,Cu为400、700、1000 mg·kg-1、Cd为1.0、3.0、6.0 mg·kg-1,30d后开始取样叶分析。结果表明：不同时间段中,防御蛋白CAT、SOD、PPO、PAL、CI、TI活性的变化规律性与重金属质量分数和时间有关,重金属胁迫30~40 d后,高质量浓度Cd、Cu处理样叶中的防御蛋白CAT、SOD、PPO、PAL、CI、TI活性显著高于对照,在第40天时达到最大,低质量分数Cd、Cu处理与对照相比差异不显著;处理50~60 d后,高质量分数Cd、Cu处理样叶中防御蛋白CAT、SOD、PPO、PAL、CI、TI活性显著低于对照,低质量分数Cd、Cu处理与对照相比差异不显著,在第60天的时降到最小。     

尖孢镰刀菌甜瓜专化型基因组规模分泌蛋白的预测与分析

利用Signal P、Wo LF PSORT、TMHMM、big-PI Predictor、Target P和Secretome P等软件,对尖孢镰刀菌甜瓜专化型(Fusarium oxysporum f.sp.melonis,FOM)全基因组26 811条蛋白质氨基酸序列进行了分泌蛋白的预测分析。结果表明,FOM全基因组编码蛋白中有1 145个经典分泌蛋白,占编码蛋白总数的4.3%;有8 471个非经典分泌蛋白,占编码蛋白总数的31.6%。对经典分泌蛋白特征进行分析,发现其氨基酸长度集中在100~600个氨基酸,信号肽长度集中在17~22个氨基酸。对经典分泌蛋白的功能预测分析表明,有605个分泌蛋白获得了注释,主要涉及糖代谢、转运过程、过氧化氢代谢和生物合成等。对碳水化合物酶类(CAZymes)进行分析,结果表明有277个分泌蛋白为CAZymes,占经典分泌蛋白总数的24.2%。     

5种不同镰刀菌的酶学特性分析

采用比色法和电泳技术对引起成年国槐根茎腐烂病的5种镰刀菌的酶学特性进行了分析,为镰刀菌的分类和生理分化研究等提供理论依据。结果表明,5种镰刀菌的可溶性蛋白含量及4种保护酶(EST、SOD、PPO和POD)活性的测定结果与电泳结果相一致,如5种镰刀菌的SOD活性都很高,介于2 263.09~6 134.42 U/mg,电泳图谱清晰,谱带颜色较深、较明亮,说明电泳法可半定量地确定保护酶活性的大小;供试的5种镰刀菌在可溶性蛋白和EST、SOD、PPO等同工酶水平上存在差异,不同镰刀菌之间某些同工酶谱带数和同一迁移率谱带的亮度和色泽差异非常明显,既存在共同谱带又有特异性谱带,如5种镰刀菌EST同工酶图谱的共同谱带占23.5%,特异性谱带占76.5%,说明5种供试病原菌均属于镰刀菌属,但分属于不同的镰刀菌种。     

16种植物源萃取物对2种植物病原菌的抑菌活性研究

为寻找和开发绿色环保且可有效抑制植物病原真菌的中草药资源,为植物源杀菌剂的开发奠定研究基础。本研究以黄瓜枯萎病菌和番茄早疫病菌为供试菌,对川芎、黄柏、连翘和地锦草乙醇提取物的16种萃取物的抑菌活性进行了测定,并观测了抑制菌丝生长效果最好的川芎石油醚萃取物对黄瓜枯萎病菌孢子萌发和菌丝形态的影响。结果表明：川芎石油醚萃取物、连翘乙酸乙酯萃取物和黄柏正丁醇萃取物对2种病菌菌丝生长均具有较好的抑制活性。其中,川芎石油醚萃取物对黄瓜枯萎病菌和番茄早疫病菌菌丝生长的抑制中浓度(IC₅₀)分别为3.68 mg/mL和5.82 mg/mL;川芎石油醚萃取物对黄瓜枯萎病菌孢子萌发也有一定抑制作用,IC₅₀为11.29 mg/mL,且在菌丝生长IC₅₀浓度下导致菌丝形态异常。川芎石油醚萃取物可作为新型植物源抑菌剂来源进一步研究。     

西瓜枯萎病菌遗传分化研究

本试验利用21个RAPD随机引物对50个西瓜枯萎病菌系进行了RAPD扩增,研究了病菌遗传多样性。结果表明,对供试菌系扩增出134条带,其中多态性带113条,占总带数的84.3%。菌系间的遗传相似系数变化在0.45~0.93之间,多数菌系间的同源程度较低。基于RAPD标记聚类分析表明,50个菌系划分为6个RAPD群(RAPDgroups,简称RGs),即RGⅠ,RGⅡ,RGⅢ,RGⅣ,RGⅤ和RGⅥ。其中RGⅠ和RGⅡ各含有一个菌系,分别来自秦皇岛和新疆;RGⅢ和RGⅤ包括2个菌系,分别来自秦皇岛、承德和廊坊、沧州;RGⅣ包括唐山、石家庄、邯郸和新疆菌系;其余的菌系属于RGⅥ。分类结果进一步说明西瓜枯萎病菌间存在着较大的遗传分化。     

Identification of Resistance Genes Against Powdery Mildew in Four Accessions of Hordeum Vulgare SSP. Spontaneum

Summary Four newly detected accessions of wild barley (Hordeum vulgare ssp. spontaneum) resistant to powdery mildew caused by Blumeria graminis f. sp. hordei were studied with the aim of finding the number of genes/loci conferring the resistance of individual accessions, the type of inheritance of the genes and their relationships to the Mla locus. F₂ populations after crosses between the winter variety ‘Tiffany’ and four wild barley accessions and use of microsatellite DNA markers were focused on the identification of individual resistance genes/loci by means of their chromosomal locations. In PI466495, one locus conferring powdery mildew resistance was identified in highly significant linkage with the marker Bmac0213. This location is consistent with the known locus Mla on chromosome 1HS. In the other three accessions the resistance was determined by two independent loci. In PI466197, PI466297 and PI466461, one locus was identified on chromosome 1HS and three new loci were revealed on chromosomes 2HS (highly significant linkage with Bmac0134), 7HS (highly significant linkage with Bmag0021) and 7HL (significant linkage with EBmac0755). Our prospective aim is identification of further linked DNA markers and the exact location of the resistance genes on the barley chromosomes.     

Involvement of polyamines, diamine oxidase and polyamine oxidase in resistance of barley to Blumeria graminis f. sp. hordei

Polyamine levels and diamine and polyamine oxidase activities have been investigated in the first leaves of barley (Hordeum vulgare L.) in the absence of or following inoculation with conidia of powdery mildew (Blumeria graminis f. sp. hordei). Two cultivars with varying sensitivity to powdery mildew, viz., Chariot (resistant) and Golden Promise (susceptible) were used. The levels of putrescine, spermidine and spermine were found to be higher in the leaves of Chariot than in the leaves of Golden Promise and, with the exception of spermine, were generally higher in both cultivars after inoculation. In inoculated leaves of Chariot, levels of putrescine and spermidine peaked at 9 days and 12 days, respectively. In controls (uninoculated leaves), the activities of these enzymes, and putrescine and spermidine levels also increased but not to the same extent as in inoculated leaves. With Golden Promise, the levels of putrescine and spermidine in the inoculated leaves changed very little over sampling times but were always higher than in the controls. In this cultivar, there was little difference between inoculated leaves and the controls in diamine oxidase activity which reached a maximum value at 9 days post-inoculation. Activity of the bound form of diamine oxidase was low in both the cultivars. Polyamine oxidase was not detected at 3 days after inoculation in either cultivar but activity at fairly low levels was recorded at later times, usually reaching a maximum value at 9 days. The results suggest that polyamine metabolism and diamine oxidase activity in particular may be involved in the mechanism conferring resistance to barley powdery mildew in Chariot.     

不同种类食用菌对黑粪蚊生长发育、繁殖及酯酶活性的影响

【目的】研究黑粪蚊(Scatopse sp.)取食不同食用菌后的生长发育、存活情况及体内磷酸酯酶和乙酰胆碱酯酶活力,为生产上利用不同种类食用菌的合理布局防止和减轻黑粪蚊危害提供科学依据。【方法】在人工控制温度(25±0.5)℃、黑暗、相对湿度(80±10)%条件下,人工接虫,系统饲养观察平菇、木耳、银耳3种食用菌对黑粪蚊生长发育、繁殖和磷酸酯酶、乙酰胆碱酯酶活力的影响。【结果】取食平菇的黑粪蚊全幼虫期的发育历期为10.4d,显著短于取食木耳(14.8d)和银耳(18.9d)的幼虫;黑粪蚊取食平菇时,幼虫存活率、蛹质量和雌虫产卵量均最大,分别为61.15%,0.74mg和145.15粒,其次为取食木耳,取食银耳的最低,分别为50.79%,0.48mg和85.79粒。取食平菇的黑粪蚊成虫寿命(3.0d)显著长于取食木耳(2.4d),取食银耳的成虫寿命居中。取食不同种类食用菌,对黑粪蚊蛹发育历期、羽化率和雌性比率影响不显著。取食平菇的黑粪蚊种群趋势指数达31.37,明显高于取食木耳(16.62)和银耳(13.49)。幼虫取食不同种类食用菌,其酸性磷酸酯酶和碱性磷酸酯酶的活力由高到低依次均为银耳>木耳>平菇,乙酰胆碱酯酶的活力由高到低依次为平菇>木耳>银耳。【结论】不同种类食用菌对黑粪蚊的生长发育、存活繁殖、磷酸酯酶和乙酰胆碱酯酶活力均有显著影响,其中平菇对黑粪蚊生长发育和繁殖最有利。