Top Dressing of Feed with Desiccated Chlamydospores of Duddingtonia flagrans for Biological Control of the Pre-Parasitic Stages of Ovine Haemonchus contortus

Feeding trials were conducted with stall-fed sheep parasitized with Haemonchus contortus. For 10 days they were offered 250 g of a concentrate feed that had been top-dressed with desiccated chlamydospores of Duddingtonia flagrans at 1×10⁵, 5×10⁵, 1×10⁶ or 2×10⁶ chlamydospores/kg body weight. Pooled faeces from each group on day 7 of spore feeding were spread on different pasture plots. On day 28 after the start of spore feeding, further pooled faeces from each group were spread on the same plots. The larval burdens on the plots were monitored for 2 months and the larval harvest from in vitro faecal cultures were monitored regularly. The application of 1×10⁶ or more spores/kg body weight virtually eliminated larvae from both the pasture and the faecal cultures. The application of as few as 1×10⁵ spores/kg body weight had a profound impact on larval recovery. The effect persisted while the spores were being fed but not for more than 4 days following discontinuation of spore feeding. Top dressing supplementary feed with dried chlamydospores offers a potential way of using D. flagrans for biological control of the pre-parasitic stages of H. contortus.     

紫外线—氯化锂复合诱变选育泰妙菌素高产菌株

目的 筛选泰妙菌素高产菌株。方法 以TMⅡ09—003为出发菌株,经UV照射180s后,将菌悬液均匀的涂布于加有0.8%的氯化锂平板上,在避光条件下于温度26℃～27℃,湿度60%～65%的环境下培养成熟后,进行挑取单菌落、初筛、复筛。以HPLC法测化学效价。结果 经UV照射180s后,氯化锂加量为0.8%剂量对菌株的致死率为88.6%。对用此剂量处理获得的诱变菌株进行了筛选,最终获得4支高产菌株,分别为：TMⅡ09—236、TMⅡ09—253、TMⅡ09—441和TMⅡ09—447。     

救必应水提取物对产ESBLs细菌的抑菌机理研究

为了探讨救必应水提取物的抑菌作用及抑菌机理,采用2倍微量稀释法和琼脂平板稀释培养计数法,测定救必应水提取物对产ESBLs(extended spectrum β-lactamases)细菌的最小抑菌浓度(minimal inhibitory concentration,MIC)和最小杀菌浓度(minimal bactericidal concentration,MBC),通过对细菌生长曲线、细菌超微结构、细胞壁和细胞膜通透性变化试验、核酸合成抑制试验研究救必应水提取物的抑菌机理。结果表明,与不添加提取物的对照组相比,救必应水提取物能够影响细菌的生长规律,使细菌破损严重,细胞壁和细胞膜通透性增加,细胞质外渗,菌液中AKP含量、可溶性蛋白含量增多、大肠杆菌DNA荧光强度明显减弱。研究表明,救必应水提取物的抑菌机理是通过细菌细胞壁和细胞膜通透性的变化,抑制细菌核酸的合成实现的。     

不同草种对土著AM真菌的生长和群落结构的影响

以果园生草栽培为背景,果园土壤中土著AM真菌为研究对象,考察了柱花草、百喜草和藿香蓟对与之根系共生的AM真菌的生长与群落结构的影响。结果表明,柱花草根系的侵染率(62.2%)显著高于百喜草(36.5%)和藿香蓟(37.3%),丛枝率有相似的趋势;3种草地上部的生物量和含磷量没有差异,但是柱花草根系含磷量显著高于百喜草和藿香蓟;柱花草根际土壤中AM真菌的菌种丰度和菌丝密度均小于百喜草和藿香蓟,但是孢子密度大于藿香蓟而小于百喜草;藿香蓟根际土著AM真菌群落的多样性指数略高于柱花草和百喜草;PCR-DGGE分析结果与之吻合。试验表明,在果园土壤中,不同草种根际的土著AM真菌群落结构并不相同,在选择草种进行生草栽培的过程中应该考虑这些不同。     

滩羊土——草——畜系统中的微量元素及其意义

甘肃景泰滩羊典型产区草地土壤中含有Ｂｅ、Ｐｂ、Ｔｉ、Ｂａ、Ｍｎ、Ｇａ、Ｃｒ、Ｎｉ、Ｖ、Ｃｕ、Ｚｒ、Ｃｏ、Ｓｒ、Ｙ、Ｙｂ等１５种微量元素。草地混合牧草吸其中的１３种,其中Ｙｂ显著减少,缺少了Ｂｅ和Ｃｏ。羊毛中微量元素的种类和含量变化很大并且复杂。滩羊成年母羊毛中只含Ｐｂ、Ｔｉ、Ｍｎ、Ｃｕ等４种元素,而二毛期即１月龄羔羊毛中含有Ｂａ、Ｐｂ、Ｔｉ、Ｍｎ、Ｃｒ、Ｎｉ、Ｃｕ、Ｚｒ、Ａｇ、Ｚｎ、Ｓｒ、Ｍｏ和Ｙ     

粗酶制剂在大麦日粮中对产蛋鸡的影响

就粗酶制剂在大麦日粮中对产蛋鸡产蛋性能的影响进行了两次试验。按０．１％比例的酶制剂添加于含大麦２８．５％和５０％的日粮中,分别饲喂３３０和２４２日龄的产蛋鸡。结果添加酶制剂对鸡产蛋率无明显提高,而对每个蛋重和鸡蛋质量有所改善,同时使产蛋鸡外周血液中促甲状腺激素和生长激素显著提高,而使甲状腺素显著降低。     

8种豆科灌木栽培种丛枝菌根真菌种类及分布

采集人工栽培决明(Cassia tora)、假木豆(Dendrolobium triangulare)、紫穗槐(Amorpha fruticosa)、白刺花(Sophora davidii)、猪屎豆(Crotalaria pallida)、多花木蓝(Indigofera amblyantha)、木豆(Cajanus cajan)和银合欢(Leucaena leucocephala)8种豆科灌木植物根际5-10、10-20和20-30 cm 3个土层的土样,研究其根际丛枝菌根(AM)真菌的侵染率、孢子密度、种类及多样性。结果表明,8种豆科灌木植物AM真菌侵染率普遍较高,最高的为猪屎豆,80.8%;土壤速效磷含量与侵染率呈显著负相关(r=-0.733,P=0.039);根际土壤中的AM真菌孢子主要分布于5-20 cm土层,5-10 cm土层猪屎豆孢子密度最大,为115.33个·10 g-1土壤;宿主植物种类与土壤层位对孢子密度交互效应影响显著(F=100.497,P0.001);AM真菌优势种枫香球囊霉(Glomus liquidambaris)、脆无梗囊霉(Acaulospora delicate)在8种豆科灌木植物的土壤中均有分布。本研究表明,喀斯特地区适生豆科灌木植物具有丰富的AM真菌资源,今后可以在喀斯特地区开展豆科灌木植物接种优势AM真菌和根瘤菌等相关研究,这将对农牧业生产和退化生态系统修复效应的影响具有重要意义。     

移动式太阳能牦牛乳产地保鲜贮藏设备的研究与设计

[目的]针对当前高原散养牦牛因缺乏电源、处理技术和装备,无法实现生鲜牦牛乳产地保鲜贮藏而造成浪费的问题。[方法]对牦牛乳热处理工艺进行研究,通过成本效益分析后,采用加热到60 ℃以上、保持30 min的巴氏高温杀菌工艺,研究了供电系统、杀菌保鲜系统以及辅助系统等。[结果]最终集成设计出加工鲜牦牛乳量达40 L/d的移动式太阳能牦牛乳产地保鲜贮藏设备。[结论]该设备能够延长牦牛乳保鲜时间,减少因不能及时产地保鲜牦牛乳造成变质损失,同时可提高牦牛乳商品转化率,促进藏区畜牧业生产效益提升。     

Stability of desiccated rhizosphere soil aggregates of mycorrhizal Juniperus oxycedrus grown in a desertified soil amended with a composted organic residue

Adequate soil structural stability favours the establishment and viability of a stable plant cover, protecting the soil against water erosion in desertified Mediterranean environments. We studied the effect of soil drying-rewetting, inoculation with a mixture of three exotic arbuscular mycorrhizal (AM) fungi (Glomus intraradices Schenck & Smith, Glomus deserticola (Trappe, Bloss. & Menge) and Glomus mosseae (Nicol & Gerd.) Gerd. & Trappe) and addition of a composted organic residue on aggregate stabilisation of the rhizosphere soil of Juniperus oxycedrus. The AM fungi and composted residue produced similar increases in plant growth, independently of the water conditions. Under well-watered conditions, the highest percentages of stable aggregates were recorded in the amended soil, followed by the soil inoculated with AM fungi. Excepting microbial biomass C, the soil drying increased labile C fractions (water soluble C, water soluble and total carbohydrates), whereas the rewetting decreased significantly such C fractions. Desiccation caused a significant increase in aggregate stability of the rhizosphere soil of all plants, particularly in the amended and inoculated plants. In all treatments, the aggregates formed after soil drying were unstable, since, in the rewetting, they disappear, reaching the initial levels before soil drying. Our results suggest that the aggregation mechanisms developed by rhizosphere microbial community of the amended and inoculated plants under water stress can be particularly relevant in desertified soils exposed to long desiccation periods.     

越冬前北京和云南葡萄溃疡病组织内相关真菌的鉴定

为了解我国不同地区在冬季修剪窗口期葡萄枝干组织中与葡萄溃疡病相关的病原微生物的种类,探索葡萄溃疡病组织中病原微生物的年周期变化,从栽培和植保角度制定防控措施,采用微生物分离、生物学特性观察,以及ITS测序的方法,对北京和云南葡萄溃疡病组织内相关真菌进行分离和鉴定。从北京的材料中分离鉴定出5种真菌:45.0%葡萄座腔菌属(Botryosphaeria),30.0%镰刀菌属(Fusarium),15.0%刺盘孢属(Colletotrichum),7.5%木霉属(Trichoderma),2.5%茎点霉属(Phoma);从云南的材料中分离鉴定出7种真菌,32.0%茎点霉(Phoma),27.0%壳囊孢属(Cytospora),14.0%拟茎点霉属(Phomopsis),14.0%葡萄座腔菌属(Botryosphaeria),4.5%附球菌属(Epicoccum),4.5%镰刀菌(Fusarium),4.5%链格孢属(Alternaria)。研究结果首次揭示出北京和云南葡萄越冬前溃疡病组织具有多种植物病原微生物共同存在的特征及主要相关真菌的种类。