玉米根围土壤中腐霉菌的分离鉴定及核糖体DNA-ITS序列分析

从兰州地区的红古、七里河等地采集玉米根围土壤标样,诱饵法与组织分离法相结合分离纯化到23株腐霉菌株,通过形态特征、培养特性、生长速度和对温度适应范围的研究,结合rDNA-ITS序列分析,将分离到的腐霉菌株鉴定为硬腐霉、终极腐霉和一个腐霉待定种。这是首次报道在我国分离到硬腐霉,为我国新记录种;终极腐霉也系首次在甘肃从玉米根围土壤中分离到。统计表明,3种腐霉菌种在兰州地区玉米根围土壤中的分离频率不同,终极腐霉出现次数最多,为优势种群,分离频率为60.9%;其次为腐霉待定种,分离频率为26.1%;而硬腐霉分离频率最低,为13.0%。     

甘肃河西马铃薯根际生防木霉菌对接骨木镰刀菌的拮抗筛选及鉴定

从甘肃省西部地区农牧交错区的马铃薯根际土壤中共分离到108株木霉菌株,通过平板对峙法筛选出10株对马铃薯干腐病主要病菌接骨木镰刀菌拮抗效果较好的木霉菌株,抗性系数均在0.826以上,其中天祝3株、永登4株、山丹3株。根据形态学特征、培养性状和ITS序列分析,将这10株生防木霉菌鉴定为哈茨木霉、长枝木霉、深绿木霉和粘绿木霉4个种。研究结果还表明,马铃薯根际土壤中的优势生防木霉菌种为哈茨木霉和长枝木霉,长枝木霉与深绿木霉对病原菌接骨木镰刀菌的拮抗作用最强。长枝木霉菌对接骨木镰刀菌有较好的拮抗效果,在国内系首次报道。     

能同时降解眍吐毒素、玉米赤霉烯酮和黄曲霉毒素的芽孢杆菌筛选

旨在筛选能够同时降解呕吐毒素、玉米赤霉烯酮和黄曲霉毒素的芽孢杆菌。先以呕吐毒素、玉米赤霉烯酮和黄曲霉毒素的混合物为唯一碳源,以母猪粪便为材料,进行霉菌毒素降解菌的驯化富集培养,得到能够降解这3种霉菌毒素的混合菌群,逐一对分离到的细菌进行呕吐毒素降解能力检测,得到10株对呕吐毒素降解率达70％以上的菌株。进而检测这10株细菌对玉米赤霉烯酮的降解能力,得到4株对玉米赤霉烯酮降解率达70％以上的菌株。再检测这4株细菌对黄曲霉毒素B1的降解能力,结果有1株细菌（ODS-1）对黄曲霉毒素B1的降解能力达78．9％。革兰氏染色结果表明ODS-1为革兰氏阴性芽孢杆菌。研究获得的ODS-1对呕吐毒素、玉米赤霉烯酮和黄曲霉毒素均有较好降解效果,为进一步开发具有霉菌毒素降解作用的产酶益生素奠定了基础。     

线叶嵩草内生真菌抗植物病原真菌活性测定

从线叶嵩草Kobresia capillifolia中分离得到7株内生真菌,经过形态学方法鉴定有3株属于镰孢属Fusarium sp.,1株属于枝顶孢属Acremonium sp.,1株属于黑团孢霉属Periconia sp.,另外有2株未产孢,不能用形态学方法鉴定。测定这7株内生真菌在不同温度下的生长速度,并以棉花立枯丝核菌Rhizoctonia solani（简称R 1）、小麦根腐离孺孢Bipolaris sorokiniana（简称B 1）、终极腐霉Pythium ultimum（简称P 1）和黄瓜枯萎病菌Fusarium oxysporum（简称F 1)作为试验菌进行了抑菌活性测定。结果表明,供试的内生真菌有71.43%表现出良好的喜低温生长的特性;7株菌株中有4株对小麦根腐离孺孢的抑制作用较强,菌株SY3的抑制作用最强,抑菌率达到了61.84%,抑菌区也在10 mm以上;有4株对棉花立枯丝核菌有抑制作用,但抑制作用较弱,抑菌区亦不明显;对黄瓜枯萎病菌的抑制作用都较弱,抑菌区不明显;仅有1株对终极腐霉有较强抑制作用,抑菌率为13.75%,抑菌区也达到了5～10 mm。     

能同时降解呕吐毒素、玉米赤霉烯酮和黄曲霉毒素的芽孢杆菌筛选

旨在筛选能够同时降解呕吐毒素、玉米赤霉烯酮和黄曲霉毒素的芽孢杆菌。先以呕吐毒素、玉米赤霉烯酮和黄曲霉毒素的混合物为唯一碳源,以母猪粪便为材料,进行霉菌毒素降解菌的驯化富集培养,得到能够降解这3 种霉菌毒素的混合菌群,逐一对分离到的细菌进行呕吐毒素降解能力检测,得到10 株对呕吐毒素降解率达70% 以上的菌株。进而检测这10 株细菌对玉米赤霉烯酮的降解能力,得到4 株对玉米赤霉烯酮降解率达70%以上的菌株。再检测这4 株细菌对黄曲霉毒素B1的降解能力,结果有1 株细菌(ODS-1)对黄曲霉毒素B1的降解能力达78.9%。革兰氏染色结果表明ODS-1 为革兰氏阴性芽孢杆菌。研究获得的ODS-1 对呕吐毒素、玉米赤霉烯酮和黄曲霉毒素均有较好降解效果,为进一步开发具有霉菌毒素降解作用的产酶益生素奠定了基础。     

饲料中霉菌及霉菌毒素的危害与控制

霉菌在自然界中分布广泛,种类繁多,大多数霉菌都能引起包括粮食及饲料在内的多种物质的霉腐变质。但不同饲料所产生的优势霉菌是不同的,而且有一定的规律性。目前,饲料中常见的产毒霉菌多为曲霉、青霉和镰刀霉。象黄曲霉毒素在玉米和花生中检出率较高,且花生上分离的...     

盐生草根际耐盐性木霉菌分离鉴定及其耐盐性评价

为获得耐盐性较强的木霉菌株,本试验采用平板分离法从采集的盐生草(Halogeton arachnoideus)根际土壤中分离鉴定了耐盐性较好的木霉菌株,并设置了不同浓度NaCl溶液模拟盐胁迫条件以评价其耐盐性.结果表明:经分离纯化共获得4株木霉菌株,其中获得1株耐盐性较好的木霉T-B菌株.结合形态学和分子生物学方法将分离获得的木霉T-B菌株鉴定为长枝木霉(Trichoderma longibrachiatum).同时,利用不同浓度NaCl溶液模拟盐胁迫条件,发现当NaCl溶液浓度为100?mmol·L?1时,在培养时间段(3～7?d)内长枝木霉菌株的生长速率与对照相比无显著差异(P?>0.05),而其产孢量显著高于对照(P?相似文献   

生防木霉菌T_2菌株对禾草腐霉病抑菌作用及机制研究

深绿木霉对引起禾草腐霉病原菌瓜果腐霉有明显的抑制作用。深绿木霉菌与瓜果腐霉对峙培养结果表明,深绿木霉菌可以包围、覆盖瓜果腐霉的菌落,同时产生大量孢子;当孢子悬浮液的浓度为4.65×106个/mL时,对瓜果腐霉菌的抑制率达53.56%。通过深绿木霉菌孢子悬浮液和3种药剂对草坪禾草腐霉病病原菌抑制效果的比较,深绿木霉孢子悬浮液浓度为1×107个/mL时与25%甲霜.霜霉的抑菌效果接近,分别为77.37%和79.57%。显微观察结果表明,深绿木霉菌丝缠绕在瓜果腐霉菌菌丝上,穿透菌丝在其内生长;或与瓜果腐霉菌的菌丝平行生长,再侵入瓜果腐霉菌内寄生。深绿木霉菌对瓜果腐霉的主要作用机制为重寄生作用。     

中国木霉新记录种俄罗斯木霉的分离鉴定及对马铃薯干腐病菌和黑痣病菌的拮抗作用简

利用稀释平板分离法从甘肃国营条山农场马铃薯连作田植株根围土样中分离到１株真菌菌株,经形态学特征、ＩＴＳ序列分析将其鉴定为俄罗斯木霉（Trichoderma rossicum）,为国内木霉新记录种。将其有伤接种马铃薯块茎,发现其对马铃薯块茎无致腐能力。对峙培养法测定该菌株对马铃薯干腐病优势病菌茄病镰刀菌（Fusarium solani）、接骨木镰刀菌（F．sambucinum）和黑痣病菌（Rhizoctonia solani）的拮抗效果,其拮抗系数均在０．７０以上,证明其具有较好生防应用潜力。     

奶牛场饲料霉菌毒素感染现状的调查与分析

随机抽取3家不同规模奶牛场饲料原料及自配料32份,采用进口ELISA试剂盒检测黄曲霉毒素、玉米赤霉烯酮、赭曲霉毒素和呕吐毒素等4种常见霉菌毒素含量。结果表明：所检测的4种霉菌毒素在所有样品中的检出率为100％,并同时含有2～3种霉菌毒素。其中,除豆粕、苜蓿干草、稻草、豆腐渣外,几乎在所有的饲料样本中玉米赤霉稀酮含量都超标,青贮玉米最高,超标4倍,TMR饲料中玉米赤霉酮含量超出了2倍以上;玉米副产品GGDS中赭曲霉毒素、玉米赤霉酮含量超标严重,呕吐霉素存在微量或少量超标;黄曲霉毒素在青贮玉米、稻草、豆腐渣中有超标,占总样品的15．63％。     

Comparisons of Angus, Charolais, Galloway, Hereford, Longhorn, Nellore, Piedmontese, Salers, and Shorthorn breeds for weight, weight adjusted for condition score, height, and condition score of cows

Breed differences for weight (CW), height (CH), and condition score (CS) were estimated from records (n = 12,188) of 2- to 6-yr-old cows (n = 744) from Cycle IV of the U.S. Meat Animal Research Center's Germplasm Evaluation (GPE) Program. Cows were produced from mating Angus and Hereford dams to Angus, Hereford, Charolais, Shorthorn, Galloway, Longhorn, Nellore, Piedmontese, and Salers sires. Samples of Angus and Hereford sires were 1) reference sires born from 1962 through 1970 and 2) 1980s sires born in 1980 through 1987. The mixed model included cow age, season of measurement and their interactions, year of birth, pregnancy-lactation code (PL), and breedgroup as fixed effects for CW and CS. Analyses of weight adjusted for condition score included CS as a linear covariate. The model for CH excluded PL. Random effects were additive genetic and permanent environmental effects associated with the cow. Differences among breed groups were significant (P < 0.05) for all traits and were maintained through maturity with few interchanges in ranking. The order of F1 cows for weight was as follows: Charolais (506 to 635 kg for different ages), Shorthorn and Salers, reciprocal Hereford-Angus (HA) with 1980s sires, Nellore, HA with reference sires, Galloway, Piedmontese, and Longhorn (412 to 525 kg for different ages). Order for height was as follows: Nellore (136 to 140 cm), Charolais, Shorthorn, Salers, HA with 1980s sires, Piedmontese, Longhorn, Galloway and HA with reference sires (126 to 128 cm). Hereford and Angus cows with reference sires were generally lighter than those with 1980s sires. In general, breed differences for height followed those for weight except that F1 Nellore cows were tallest, which may in part be due to Bos taurus-Bos indicus heterosis for size.     

Supplementation of broodmares with copper, zinc, iron, manganese, cobalt, iodine, and selenium

In experiment 1, 6 pregnant mares received a concentrate that contained a trace mineral premix that provided 14.3 mg Cu, 40 mg Zn, 28 mg Fe, 28 mg Mn, 0.08 mg Co, 0.16 mg I, and 0.16 mg Se/kg concentrate (group A). Seven mares received the same concentrate plus 502 mg Zn and 127 mg Cu once daily (group B). No differences (P > .05) in foal growth data, or Cu, Zn, and Fe concentrations of mare milk, mare serum, or foal serum were observed. In experiment 2, 6 pregnant mares received the same concentrate as group A (group C), and 8 mares received the same concentrate fortified with 4× the trace mineral premix (group D). Group C mares had higher serum Zn concentration at 1 day (P < 0.01) and 56 days (P < 0.04). Group C mares had higher milk Fe concentration at 28 days (P < .01), and group D mares had higher milk Cu concentration at 56 days (P < .01). Group C foals had higher serum Cu concentration at 14 days (P < .03). The results from this study provide no evidence to indicate that supplementing late gestating and lactating mares with higher dietary trace mineral levels than those recommended currently by NRC has any influence on foal growth and development, or on the Cu, Zn, and Fe concentrations of the mare milk, mare serum, or foal serum.     

Concentrations of strontium,barium, cadmium,copper, zinc,manganese, chromium,antimony, selenium,and lead in the liver and kidneys of dogs according to age,gender, and the occurrence of chronic kidney disease

This study was conducted to measure the concentrations of strontium (Sr), barium (Ba), cadmium (Cd), copper (Cu), zinc (Zn), manganese (Mn), chromium (Cr), antimony (Sb), selenium (Se), and lead (Pb) in canine liver, renal cortex, and renal medulla, and the association of these concentrations with age, gender, and occurrence of chronic kidney disease (CKD). Tissues from 50 dogs were analyzed using inductively coupled plasma mass spectrometry. Cu, Zn, and Mn levels were highest in the liver followed by the renal cortex and renal medulla. The highest Sr, Cd, and Se concentrations were measured in the renal cortex while lower levels were found in the renal medulla and liver. Female dogs had higher tissue concentrations of Sr (liver and renal medulla), Cd (liver), Zn (liver and renal cortex), Cr (liver, renal cortex, and renal medulla), and Pb (liver) than male animals. Except for Mn and Sb, age-dependent variations were observed for all element concentrations in the canine tissues. Hepatic Cd and Cr concentrations were higher in dogs with CKD. In conclusion, the present results provide new knowledge about the storage of specific elements in canine liver and kidneys, and can be considered important reference data for diagnostic methods and further investigations.     

电感耦合等离子-质谱法测定饲料中钠、镁、铬、锰、铁、铜、锌、砷、硒、镉和铅

应用电感耦合等离子-质谱技术(ICP-MS),建立饲料中钠、镁、铬、锰、铁、铜、锌、砷、硒、镉和铅等元素的测定方法。对饲料样品的前处理方法、仪器工作参数和11种元素标准曲线进行优化;并以加标回收、分析方法比对和重复测试说明方法的准确性和精密性。方法在0～1 000 ng/ml范围内线性良好,仪器检出限为0.557 7～5.072 ng/ml,具有良好的精密度,其回收率在88.1%～104.4%之间,相对标准偏差小于5.0%。同时与原子吸收和原子荧光方法进行比对,测定结果相近。所建立的方法简单、快速,可替代原子吸收和原子荧光方法测定饲料中的11种金属元素,为饲料的质量控制提供理想的元素分析方法。     

Granulocyte isolation from whole blood of goat, sheep, cattle, horse, dog, pig, and man

A simple two step procedure for the isolation of caprine, ovine, bovine, equine, canine, porcine and human peripheral blood granulocytes is described. After enrichment of granulocytes by centrifugation, contaminating erythrocytes are lysed hypotonically. Recovery, purity, and viability of the granulocyte suspensions are determined. FACScan analysis of the cell suspensions measuring cellular size by forward and sideward light scatter is compared with the corresponding analysis of whole blood leukocytes. Constituencies of the isolated cell suspensions and loss of granulocyte subpopulations through isolation procedure is discussed with regard to granulocyte function assays.     

Department of Clinical Veterinary Practices, School of Veterinary Medicine, University of Dublin, Trinity College, Ballsbridge, Dublin 4

Circular excised skin wounds in the thoracic and metatarsal regions of the dog were studied. A similar sequence of events took place in the two regions although differences did occur due to the different reactions of the tissues which surrounded the wounds. None of the wound cavities became filled with exudate during the early stages of healing. In the thoracic wounds the cavities were largely filled by the swelling and inward movement of adipose tissue. Epithelium first grew on the wound surface in the sector of the wound that was situated in the direction of hair flow. The average time to complete epithelization was similar in both sets of wounds. A zone of alopecia developed around the wounds.