不同丛枝菌根真菌种类对生姜生长的影响

研究盆栽条件下,接种不同丛枝菌根真菌（arbuscular mycorrhizal fungi, AMF）种类对生姜不同生育时期农艺性状的影响及其在生姜根内的定殖情况。采用生姜组培苗,于幼苗期分别接种12株AMF进行生姜农艺性状比较试验,在温室盆栽接种后每隔30 d对生姜根系进行取样分析,比较菌根侵染率、侵染强度和丛枝丰度的大小,以观察不同AMF菌株对生姜苗的侵染动态。结果表明,所有接种AMF组的生姜植株,其生长量均高于空白对照组。结合不同菌株在根系的侵染率,筛选出生姜AMF优势种类为：细凹无梗囊霉（Acaulospora scrobiculata）、网状球囊霉（Glomus reticulatum）、隐形球囊霉（Paraglomus occltum）、摩西球囊霉（Glomus mosseae）。说明苗期接种这4个优势菌种,能够促进生姜生长,是适宜生姜生长的优良AMF菌株。     

Wild Bonelli’s eagles (Aquila fasciata) as carrier of antimicrobial resistant Salmonella and Campylobacter in Eastern Spain

Wild birds have repeatedly been found to be involved in the dissemination of enteric bacterial pathogens in the environment. The aim of this study was to determine the occurrence of Salmonella and Campylobacter as well as the antimicrobial resistance in wild Bonelli’s eagles nestlings in Eastern Spain. In addition, we compared the efficiency of two sampling methods (fresh faecal samples from nest and cloacal swabs from nestlings) for detection of both bacteria. A total of 28 nests with 45 nestlings were analysed. In the nest, Salmonella occurrence was 61 ± 9.2%, while Campylobacter occurrence was 11 ± 5.8% (p < 0.05). In the nestlings, Salmonella occurrence was 36 ± 7.1%, while Campylobacter occurrence was 11 ± 4.7% (p < 0.05). Eight Salmonella serovars were identified, and the most frequently isolated were S. Enteritidis, S. Typhimurium, S. Houston, and S. Cerro. Only one Campylobacter species was identified (C. jejuni). Regarding antimicrobial resistance, the Salmonella strains isolated were found to be most frequently resistant to ampicillin and to tigecycline; however, the sole Campylobacter strain recovered was multidrug resistant. In conclusion, this study demonstrated that wild Bonelli’s eagles nestlings are greater carriers of Salmonella than of Campylobacter. Both Salmonella and Campylobacter isolates exhibited antimicrobial resistance. In addition, faecal samples from nests were most reliable for Salmonella detection, while cloacal swab from nestlings were most reliable for Campylobacter detection.     

河南省地方良种鸡蛋壳质量性状的对比

在了解了河南省地方良种鸡的蛋壳质量性状后,为对河南省4个地方良种鸡的蛋壳颜色、蛋的比重、蛋壳厚度及其占蛋重的比例进行了测定。结果：蛋壳颜色均以浅褐色和灰色为主,其中正阳三黄鸡蛋壳颜色偏深、淅川乌鸡蛋壳颜色偏浅;蛋的比重均在1．11以上;蛋壳重量占蛋重的比例以固始鸡最低（10．97％）、浙川乌鸡最高（11．84％）;平均蛋壳厚度以正阳三黄鸡最高（0．342mm）、卢氏鸡最低（0．325mm）。     

Pigmentation of the aortic and pulmonary valves in C57BL/6J x Balb/cByJ hybrid mice of different coat colours

Neural crest‐derived melanocytes have been recorded in several parts of the mammalian heart but not in the pulmonary valve. We report here the presence of melanin‐containing cells in the leaflets (cusps) of both the aortic and pulmonary valves. A total of 158 C57BL/6J x Balb/cByJ hybrid mice exhibiting four coat colours, namely black, white, agouti and non‐agouti brown, were examined. We sought for any relationship between the presence of melanocytes in the valves and the coat colour of the animals. The pigmentation levels of the leaflets were accomplished using a scale of five pigment intensities. White mice lacked pigment in the heart. In 10.5% of the remaining animals, there were melanocytes in the pulmonary valve leaflets. Thus, this is the first study to report the presence of such cells in the pulmonary valve of mammals. Melanocytes occurred in the leaflets of the aortic valves of 87.2% of mice. The incidence of melanocytes and the pigmentation level of the leaflets did not statistically differ according to the coat colours of the animals. This disagrees with previous observations, indicating that the amount of melanocytes in the heart reflects that of the skin. The incidence and distribution of melanocytes in aortic and pulmonary valves are consistent with the notion that the formation of the arterial valves is mediated by specific subpopulations of neural crest cells. We hypothesize that melanocytes, even not producing melanin, may be more frequent in the heart than previously thought, exerting presumably an immunological function.     

Recreational sandboxes for children and dogs can be a source of epidemic ribotypes of Clostridium difficile

Different studies have suggested that the sand of public playgrounds could have a role in the transmission of infections, particularly in children. Furthermore, free access of pets and other animals to the playgrounds might increase such a risk. We studied the presence of Clostridium difficile in 20 pairs of sandboxes for children and dogs located in different playgrounds within the Madrid region (Spain). Clostridium difficile isolation was performed by enrichment and selective culture procedures. The genetic (ribotype and amplified fragment length polymorphism [AFLP]) diversity and antibiotic susceptibility of isolates was also studied. Overall, 52.5% (21/40) of samples were positive for the presence of C. difficile. Eight of the 20 available isolates belonged to the toxigenic ribotypes 014 (n = 5) and 106 (n = 2), both regarded as epidemic, and CD047 (n = 1). The other 12 isolates were non‐toxigenic, and belonged to ribotypes 009 (n = 5), 039 (n = 4), and 067, 151 and CD048 (one isolate each). Nevertheless, all isolates (even those of a same ribotype) were classified into different AFLP genotypes indicating non‐relatedness. In conclusion, our results revealed the presence of epidemic ribotypes of C. difficile in children's and dog's sandboxes located nearby, which constitutes a major health risk.     

不同微生物添加剂组合固态发酵对木薯渣品质的影响

本试验旨在研究布氏乳杆菌(LAB)、黑曲霉(AN)、热带假丝酵母(CT)、枯草芽孢杆菌(BS)与植物乳杆菌(LAP)组合对木薯渣品质的影响,筛选出发酵效果最优的混合菌组合。试验以木薯渣为发酵原料,对LAB、AN、CT、BS与LAP进行不同菌种的菌液以1∶1体积比组合,共设5个不同组合,组合1:LAB+AN+CT+LAP;组合2:LAB+AN+BS+LAP;组合3:LAB+CT+BS+LAP;组合4:AN+CT+BS+LAP;组合5:LAB+AN+CT+BS+LAP;各组合分别添加1%尿素或者1%尿素+0.6%红糖,空白组不添加任何添加剂,对照组Ⅰ添加1%尿素;对照组Ⅱ添加1%尿素+0.6%红糖,各组均用生理盐水调制含水量为65%左右,于聚乙烯薄膜袋中真空发酵10 d。结果表明:1)不同微生物添加剂组合发酵木薯渣对木薯渣营养成分改善效果5菌组合优于4菌组合。其中,LAB+AN+CT+BS+LAP+尿素+红糖组合发酵木薯渣效果最好,与空白组相比显著降低了发酵木薯渣p H(P0.05),提高了乙酸和丙酸含量;中性洗涤纤维(NDF)和酸性洗涤纤维(ADF)含量均为最低,显著低于空白组和对照组(P0.05);粗蛋白质(CP)含量最高,显著高于空白组和对照组(P0.05)。2)添加相应的菌种+尿素+红糖发酵木薯渣有利于产生丙酸。3)在发酵培养基中添加尿素能显著提高木薯渣CP含量(P0.05)。4)在木薯渣发酵过程中添加尿素+红糖比只添加尿素对木薯渣营养成分改善效果好。综上所述,LAB、AN、CT、BS与LAP组合添加尿素和红糖固态发酵木薯渣,可以有效改善木薯渣品质。     

北方棉区棉花黄萎病菌落叶型菌系鉴定

 采用RAPD扩增与温室致病性测定2种方法,以黄萎病菌Verticillium dahliae的5个落叶型、7个非落叶型菌系和V.albo-atrum的2个菌系为对照,对采自北方棉区6省(自治区)的34个棉花黄萎病菌菌系进行致病型鉴定。94.1%的菌系在2种鉴定结果中表现一致,与对照菌系相比较,确定其中26个菌系为落叶型菌系,6个菌系为非落叶型菌系。从而证实了黄萎病菌落叶型菌系在北方棉区河北、河南、山东3省的存在,并发现所确定的26个北方落叶型菌系中的22个与来自美国的对照落叶型菌系T₉、V₄₄的关系比与来自江苏的对照落叶型菌系V_B、V₉₉₁的关系更近。本实验还初步筛选到2条用于鉴别V.dahliae落叶型与非落叶型菌系的RAPD特异条带OPB-19₉₆₆和OPM-20₁₆₉₁,将它们用于对34个北方菌系的RAPD扩增鉴定,则与温室致病性测定结果的一致性分别为88.2%和94.1%,证明这2条特异条带在鉴定棉花黄萎病菌落叶型菌系上具有一定的实用价值,并为进一步制作特异探针以形成一套简便、准确、规范化的鉴定技术奠定了基础。     

马桑根瘤内生菌纯培养物的分离、回接及其生物学特性

多次采用根瘤切片法直接从野生的马桑根瘤中分离内生菌纯培养物均未获成功;但用同样方法从温室里人工接种形成的马桑根瘤中却分离到大量纯培养物。其中273株经盆栽回接后发现有24株能侵染结瘤;少数菌株还通过半固体斜面和珍珠岩盆栽回接成功。对10株纯培养物表型特性的研究表明,它们均具有Frankia的形态和培养特征;生理类型除有A、B两型外,尚出现有一类A、B混合型,其中凡属B型菌株的均能侵染结瘤,A型则不能,两株A、B混合型中有1株能结瘤,另1株却不能;碳、氮源利用特性和其它Frankia基本相似;细胞壁组分既有Ⅲ型也有Ⅱ型;全细胞鉴别性糖大多为木糖和半乳糖,少数菌株只含有半乳糖或木糖,或含有半乳糖、木糖和阿拉伯糖。DNA中G+C mol%为65%～74%。     

柔嫩艾美耳球虫耐药株与鸡3种球虫的同工酶的研究

对不同离子载体抗生素具有抗药性的柔嫩艾美耳球虫和药物敏感的柔嫩区美耳球虫、布氏匀美耳球虫和堆型艾耳球虫的孢子化卵囊,采用聚安凝胶垂直板电泳,进行了乳酸脱氢酶（ＬＤＨ）、葡萄糖磷酸异构酶（ＧＰＩ）和葡萄糖－６－磷酸脱氢酶（Ｇ６ＰＤ）等同工酶华不同离子载体抗生素具有抗药性的柔嫩艾美耳球虫和药物同工酶酶谱可以反应出球虫种间差异;而柔嫩艾耳球虫抗性虫株的ＬＤＨ酶谱是２条带,敏感虫株是３条带,抗性株比敏感株