巴西橡胶树棒孢霉落叶病病原菌的生物学特性

研究多主棒孢菌(Corynespora cassiicola)的生物学特性,结果表明,菌丝生长的最适温度为28℃,最适pH为6～9,孢子萌发的最适温度为28～30℃。该菌能有效利用各种碳源和氮源,碳源以麦芽糖最好,氮源以蛋白胨最好。光照处理对菌丝生长速度影响不显著,交替光照有利于产孢。菌丝致死温度是60℃,15min;分生孢子的致死温度是55℃,5min。在PDA,PSA,Czapek等培养基上生长良好,但不能大量产孢,在保湿的卫生纸、玻璃片和橡胶离体叶片上,能大量产孢。     

椰子平脐蠕孢叶斑病病原鉴定及生物学特性测定

2012年10月,在海南省文昌市的椰子苗圃中,发现了一种新的叶斑病。显微观察表明,病原菌分生孢子稍弯曲,浅褐色,纺锤状或梭状,具有5~9个假隔膜、分生孢子梗多单生,直立或稍弯曲,表明其为平脐蠕孢属(Bipolari.sp)。ITS序列分析表明其和4株狗尾草平脐蠕孢的序列同源性(HE792936.1,JX462256,GUO73108.1,FJ606786.1)的同源性为99%。生物学特性研究结果表明:该菌菌丝适宜生长温度为20~30℃,菌丝生长和孢子最适萌发温度分别是25℃和30℃;最适p H值为4~11;玉米粉培养基(CAM)及马铃薯葡萄糖琼脂培养基(PDA)最适合菌丝生长,最佳碳源为蔗糖,甘油不适合菌丝生长;最佳氮源为蛋白胨,其次是磷酸氢二铵;完全光照有利于菌丝生长。菌丝及分生孢子的致死温度和时间分别是56℃,15 min。     

木薯棒孢霉叶斑病病原鉴定及其生物学特性测定

对中国木薯主产区的病害普查中,发现了一种新的叶斑病。病原菌形态鉴定和ITS序列分析表明其为山扁豆生棒孢(Corynespora cassiicola)。生物学特性研究表明,CMA或ME培养基、26~28℃、pH6、连续光照是其生长最适条件,光暗交替或连续光照适于产孢,孢子最适萌发温度和致死温度分别为28～30℃和55℃10 min。接种试验表明该菌株和2株来自于番木瓜、2株来自于橡胶的C.cassiicola菌株均能侵染木薯和番木瓜,但致病力存在着差异。除一株来自番木瓜的菌株外,其余4个菌株均能侵染橡胶。     

苦瓜双色平脐蠕孢叶斑病病原菌的生物学特性及其抑菌药剂筛选

为了明确苦瓜双色平脐蠕孢叶斑病菌（Bipolaris bicolor）的生物学特性及其对杀菌剂的敏感性,研究了不同培养条件对该病原菌菌丝生长的影响,并测定了10种杀菌剂对该病原菌的抑制作用。结果表明：该病原菌菌丝生长最适温度为25~30 ℃,最适pH范围为6~7,适宜培养基为马铃薯蔗糖培养基（PSA）和玉米粉培养基（CMA）,持续黑暗和光暗交替有利于菌丝生长;不同碳源和氮源对菌丝生长的影响差异显著,其中葡萄糖和蛋白胨分别为最适碳源和氮源,菌丝生长致死温度为45 ℃。250 g/L苯醚甲环唑乳油毒力最强,EC₅₀为0.0233 mg/L,其次为250 g/L吡唑醚菌酯悬浮剂、20%抑霉唑水乳剂和50%嘧菌环胺水分散粒剂。     

玉米穗腐病样本中温和镰孢菌的鉴定及其生物学特性

为明确引起玉米穗腐病的一种不常见镰孢菌病原菌及其生物学特性,对采集的镰孢菌穗腐病样本进行病原菌分离和纯化,并通过柯赫氏法则（Koch''s Rule）、形态学特征和分子生物学技术对菌株进行鉴定。结果表明,分离到的菌株ZBSF002为温和镰孢菌（Fusarium temperatum）,是玉米穗腐病的致病菌。对其生物学特性研究表明,温和镰孢菌的最适碳源是可溶性淀粉,最适氮源是酵母浸粉,生长温度范围为10℃~35℃,最适温度为30℃。在pH值为4~11的培养基上均能生长和产孢,在pH值7~10培养基上菌丝生长较快且产孢量较大。光照对菌丝生长和产孢量影响不显著,菌株在光照、黑暗、交替光照3种培养条件下均能生长和产孢,连续光照条件下菌丝生长较快,且产孢量较大。病原菌菌丝和分生孢子致死温度为65℃、10 min。     

芒果可可球二孢蒂腐病菌生物学培养特性

对芒果可可球二孢蒂腐病菌(Botryodiplodia theobromae Pat.)的生物学培养特性进行了研究.结果表明:菌丝生长最适温度30℃;孢子萌发最适温度30℃;菌丝生长最适pH值5～6,孢子萌发最适pH值7～10;菌丝生长的最佳碳源是棉子糖、葡萄糖,最佳氮源是牛肉浸膏、蛋白胨:光照及振荡培养对菌丝生长无显著影响;菌丝的致死温度为60℃,30 min或65℃,10 min,孢子的致死温度50℃,15min.     

海南芒果果腐病病原菌鉴定及其生物学特性研究

对引起芒果果腐病的病原菌进行鉴定,并对该病原菌的生物学特性进行初步研究。结果表明：引起芒果果腐病的病原菌是芒果拟盘多毛孢[Pestalotiopsis mangiferae（Henn.）Steyaert],该菌菌丝生长最适温度为25～28 ℃,孢子萌发最适温度为32 ℃,致死温度为60 ℃,10 min;菌丝生长最适pH为4～5,而孢子萌发最适pH为4;最适碳源为甘露醇,而麦芽糖不利于菌丝生长;最适氮源为牛肉浸膏、蛋白胨,而尿素不利于该菌菌丝生长;该菌适合在暗光交替和黑暗中生长。     

火龙果黑斑病菌[Bipolaris cactivora（Petrak）Alcorn]生物学特性研究

为了明确分离自火龙果黑斑病的病原种类、生物学特性及防治方法,对该病菌进行了种类鉴定、生物学特性研究以及室内药剂筛选。结果表明,引起该火龙果病害的病原菌为仙人掌平脐蠕孢[Bipolaris cactivora（Petrak）Alcorn]。该病菌菌丝生长最适温度是30 ℃,产孢最适温度20 ℃。菌丝生长最适pH为5,产孢最适pH8。光照对菌丝生长无显著影响,黑暗条件有利于产孢。菌丝生长最佳碳源是葡萄糖和D-果糖,产孢最佳碳源为甘露醇。菌丝生长和产孢的最佳氮源均为蛋白胨,菌丝致死温度为70 ℃,10 min。     

鹤望兰叶斑病菌的鉴定及生物学特性

鹤望兰（Srelizia regne）叶斑病菌鉴定为柯氏帚梗柱孢霉菌（Cylindroclalium collouniperdl colouni）。该病原菌的菌丝在不同培养基里生长情况不一致,其中以Richards培养基最佳。在5种培养基中Richards培养基和PCA培养基不产孢。菌丝生长的适宜温度为15~35℃,适宜pH是5.01~6.49,分生孢子萌发的适宜温度为25~30℃.病原菌分生孢子在碳源的利用上,D-葡萄糖、蔗糖、淀粉明显优于麦芽糖、D-果糖和乳糖∶;对氮源的利用以酵母浸膏、牛肉浸膏、硝酸铵明显优于蛋白陈、L-天冬氨酸和硫酸铵。     

油茶叶枯病菌的鉴定及生物学特性研究

从海南五指山油茶园区采集到油茶叶枯病叶,进行病原菌分离鉴定并对其生物学特性进行研究.通过对其培养特性、形态特征的观察及rDNA的转录间隔区(ITS)序列测定,与Genbank中同源性较高的菌株进行序列比对,将该病原菌OC-12确定为小孢拟盘多毛孢(Pestalotiopsis microspora).生物学特性研究结果表明:OC-12菌丝在PDA培养基上生长最佳,在crapek培养基上不产孢,在燕麦培养基上最适合产孢.菌丝生长和分生孢子产生的适宜温度分别为20～30℃和25℃,适宜pH值为4～11.供试碳源中果糖较利于菌丝生长,D-葡萄糖较利于孢子产生;供试氮源中蛋白胨和硝酸钾较利于菌丝生长,且蛋白胨较利于孢子产生.分生孢子致死温度为52℃,10 min.     

Physicochemical Studies on Resistant StarchIn VitroandIn Vivo

Resistant starch (RS), producedin vitroby hydrolysis of retrograded pea starch gels and amylose gels by porcine pancreaticalpha-amylase, was characterised by X-ray diffraction, size exclusion chromatography and methylation analysis. These techniques showed that RSin vitroconsisted of semi-crystalline, mostly linear material that was present in two main molecular size subfractions (DP_n>100 andDP_n20–30) with a third, minor subfraction (DP_n≤5). The extent of retrogradation of amylose was found to be of primary importance in determining the RS content of starch. Analysis ofin vivoRS, recovered during an ileostomy study, produced results that were similar to those obtained from RSin vitro. Anin vitromodel for the structure of resistant starch is proposed.     

Alpha-amylase/subtilisin Inhibitor Levels in Australian Barleys

An enzyme-linked immunosorbent assay (ELISA) was used to determine the bifunctional alpha-amylase/subtilisin inhibitor (BASI) content of barley grain from 11 cultivars grown in six diverse locations in Australia. The inhibitor ranged from 119 to 254 μg/g in 57 barley samples. Genotype had a significant (P<0·05) effect on BASI content but there was no effect due to environment. Total protein varied independently of BASI and was influenced by environment and genotype. BASI content was higher (P<0·05) in malting barley than in feed barley and was correlated positively (r=0·29;P<0·05) with alpha-amylase activity in corresponding malts. The ELISA used monoclonal and polyclonal antibodies raised against purified BASI. In immunoblot analysis the monoclonal antibody showed high specificity for the inhibitor in barley and also detected the inhibitor in wheat. Low levels of inhibitor (mean 3·2 μg/g) were found in 12 Australian wheat cultivars using the ELISA developed for barley. The assay had a linear working range of 5–50 ng/mL with a detection limit of 2 ng/mL. Reproducibility between assays was good (CV=4·9%) but mean recoveries were high, ranging from 116–129% when purified inhibitor was added to barley extracts. The ELISA may have useful applications in brewing research and barley breeding programmes.     

NR/ENR/SiO_2复合材料的阻尼性能研究

采用机械混炼的方法制备不同ENR含量的NR/ENR/SiO2复合材料,使用动态热机械分析仪(DMA)和橡胶加工分析仪(RPA)对NR/ENR/SiO2复合材料的动态力学性能和阻尼性能进行分析。结果表明:ENR对NR/ENR/SiO2复合材料的阻尼性能具有显著影响。动态热机械分析测试结果表明,随着ENR用量的增多,NR/ENR/SiO2复合材料在使用温度范围内的损耗因子积分面积增大,阻尼性能提高。橡胶加工分析频率扫描和应变扫描测试结果表明,在频率小于10 HZ不同应变时,加入了ENR的NR/ENR/SiO2复合材料的阻尼因子均高于NR/SiO2复合材料。扫描电镜分析结果证实,ENR的加入减少了SiO2的自聚,改善了填料在橡胶基体中的分散,从而使NR/ENR/SiO2复合材料力学性能得到提高。     

In VitroDigestion of Wheat Microstructure with Xylanase and Cellulase fromTrichoderma reesei

Resistant starch (RS), producedin vitroby hydrolysis of retrograded pea starch gels and amylose gels by porcine pancreaticalpha-amylase, was characterised by X-ray diffraction, size exclusion chromatography and methylation analysis. These techniques showed that RSin vitroconsisted of semi-crystalline, mostly linear material that was present in two main molecular size subfractions (DP_n>100 andDP_n20–30) with a third, minor subfraction (DP_n≤5). The extent of retrogradation of amylose was found to be of primary importance in determining the RS content of starch. Analysis ofin vivoRS, recovered during an ileostomy study, produced results that were similar to those obtained from RSin vitro. Anin vitromodel for the structure of resistant starch is proposed.     

纳米TiO_2/天然橡胶复合材料的抗菌性研究

采用溶胶凝胶法,以钛酸四丁酯掺杂金属Ag制备纳米二氧化钛(Ag-TiO2)水溶胶,并与天然胶乳湿法共混制备得到纳米TiO2/天然橡胶复合材料。紫外可见光谱表明,金属Ag能提高TiO2的光催化性能;透射电子显微镜观察到TiO2颗粒粒径为50nm左右,并且均匀的吸附在胶粒表面。研究此复合材料的抗菌性能结果表明,其具有良好的抗细菌和抗霉菌效果,对大肠杆菌的抗菌率达到90%以上,特别是硫化过后的纳米TiO2/天然橡胶复合材料的抗细菌率更达98.5%。     

Polymorphism of Low Mr Glutenin Subunits in Triticum tauschii

A collection of 173 Triticum tauschii accessions was analysed to evaluate the variability of low molecular weight (M_r) glutenin subunits. These proteins were analysed by one-step one-dimensional sodium dodecyl sulphate-polyacrylamide gel electrophoresis (SDS-PAGE) and were divided into B-, C- and D-subunits in accordance with their electrophoretic mobility. Extensive polymorphism, both in the number and electrophoretic mobility, was detected in lowM_r glutenin subunits present in T. tauschii. Thirty different patterns for B-subunits and forty-three for C-subunits were identified, some of which were with identical electrophoretic mobility than those observed in hexaploid wheat. Glutenin subunits with the same electrophoretic mobilities of low M_r D-glutenin subunits as well as subunits encoded at the Glu-D4 and Glu-D5 loci, were also detected in accessions of T. tauschii. These results provide new basic knowledge regarding the genetics variability of the low M_r glutenin subunits, as well as their potential to create novel germplasm for the improvement of wheat quality in breeding programs.     

巴西橡胶树AnnHb1基因的克隆及表达分析

根据一个从巴西橡树胶乳cDNA文库中获得的EST片段的序列设计引物,通过RACE的方法获得了橡胶树编码annexin的cDNA,命名为AnnHb1。序列分析表明,AnnHb1长为1 198 bp,含有945 bp的阅读框,62 bp的5'-UTR和191 bp的3'-UTR,编码314个氨基酸,分子量为35.99 ku,等电点为8.18。该氨基酸序列与蓖麻、麻疯树、棉花、苜蓿、烟草和拟南芥中的annexin的同源性分别为82%、72%、72%、64%、60%和60%。半定量RT-PCR分析结果表明AnnHb1基因在愈伤、花、树皮、叶、胶乳中均有表达,其中在愈伤组织中表达量最低,树皮中表达量最高。     

Protein Inhibitors ofAlpha-amylase in Mature and Germinating Grain of Rye (Secale cereale)

The activities of endogenous (R-type) and exogenous acting (D-type) protein inhibitors ofalpha-amylase and the activities ofalpha- and total amylase were determined in milling fractions of rye. High D-type amylase inhibitor activities were detected in the embryo (255 IU/g) and in the endosperm fraction (64·9 IU/g), low inhibitor activities were found in the aleurone layer fraction (25·9 IU/g). The highest R-typealpha-amylase inhibitor activity was found in the aleurone layer fraction (32·6 IU/g), and the lowest value in the epidermis containing fraction (5·0 IU/g). The D- and R-typealpha-amylase inhibitor activities varied with growing conditions. D-type amylase inhibitor activities were found to be high in those samples which grew under drought conditions and low in samples cultivated under wet and cool weather. Higher R-typealpha-amylase inhibitor activities were found in rye genotypes cultivated under wet conditions and lower values under dry weather. There were small variations inalpha-amylase inhibitor activities between sprout-stable and sprout-sensitive rye genotypes. The D- and R-typealpha-amylase inhibitor activities of all varieties were stable during 72 h of germination. Similar soil conditions will therefore lead to differentialalpha-amylase inhibitor activities depending on weather conditions during growth.     

环氧天然胶／天然胶／高乙烯基顺丁胶共混物研究

环氧化天然胶／天然胶／高乙烯基顺丁胶（ＥＮＲ／ＮＲ／Ｈｖ－ＢＲ）共混物形成ＥＮＲ和ＮＲ／Ｈｖ－ＢＲ两相体系，加入吸附剂ＡＣ能消除塑化剂渗出。ＥＮＲ／ＮＲ／Ｈｖ－ＢＲ共混物具有较好的减震性能、优异的力学性能及较高的低温应力保持率。