3株芽孢杆菌对刺参池塘有机物的降解效果及鉴定

为修复刺参Apostichopus japonicus养殖池塘底质环境,根据菌株对底泥中有机质(COD)、氨氮(NH_4~+-N)和亚硝酸盐(NO_2~--N)的去除率,从刺参养殖池塘底泥和商品益生菌中筛选高效降解刺参养殖池塘底质有机污染物的潜在益生芽孢杆菌,并对筛选出的优良菌株的产酶能力和降解特性进行了研究。结果表明:从分离的11株细菌中经过筛选最终获得3株优良菌株(N1、DL、R),它们能同时高效降解底泥中COD、NH_4~+-N和NO_2~--N,5 d内对COD的最大去除率分别为45.71%、23.98%、24.97%,对NH_4~+-N的最大去除率分别为60.54%、36.15%、36.74%,对NO_2~--N的最大去除率分别为52.10%、14.41%、28.82%;根据菌株生理生化特性以及16S r DNA序列分析,N1、DL、R菌株分别为白翎芽孢杆菌Bacillus baekryungensis、地衣芽孢杆菌B.licheniformis和解淀粉芽孢杆菌B.amyloliquefaciens。本研究结果可为进一步开发高效的刺参养殖池塘底质有机污染物降解益生菌及复方制剂提供参考。     

苹果轮纹病菌对苯醚甲环唑和氟硅唑的敏感性及其交互抗性

 为明确苹果轮纹病菌对苯醚甲环唑和氟硅唑的敏感性状况,本研究采用菌丝生长速率法检测了90个采自山东省各地区的苹果轮纹病菌对苯醚甲环唑和氟硅唑的敏感性。实验结果表明,苯醚甲环唑和氟硅唑对轮纹病菌的EC₅₀平均值分别为0.198 1±0.247 1 μg·mL^-1和0.117 4±0.121 8 μg·mL^-1。频次分布图显示,苹果轮纹病菌群体中出现了敏感性降低的亚群体。三唑类杀菌剂苯醚甲环唑、氟硅唑和戊唑醇之间具有交互抗性;而三唑类杀菌剂苯醚甲环唑、氟硅唑、戊唑醇与代森锰锌之间不存在交互抗性。田间试验结果表明,苯醚甲环唑和氟硅唑对高敏感性和低敏感性病菌引起的枝干轮纹病具有同等的防治效果。本研究结果为田间防控苹果轮纹病的杀菌剂合理轮换使用提供了理论依据。     

绒山羊USP9Y基因的BAC筛选与鉴定

USP9Y是与精子生成密切相关的基因,在动物繁殖育种中起非常重要的作用。为了进一步探讨其在绒山羊精子生成中的作用机理,提高育种率,本研究依据牛的USP9Y基因序列设计引物,运用PCR技术,对绒山羊BAC文库进行USP9Y基因的筛选、克隆、测序鉴定。并将测序所得的部分序列与不同物种进行序列比对,结果显示,目的片段与牛的同源性为98%,与家猫的同源性为95%,与人、恒河猴、黑猩猩等的同源性为89%,表明该基因在进化过程中具有一定的保守性。USP9Y基因的BAC筛选,为后续BAC测序,进一步获得USP9Y全序列及功能研究,充分开发绒山羊的经济价值奠定基础。     

江阴地区春季樱桃番茄品种比较试验

为筛选出适宜江苏江阴地区栽培的樱桃番茄品种,引进了7个樱桃番茄品种,并将其与当地主栽品种千禧樱桃番茄进行了比较试验。结果表明:粉娘樱桃番茄产量最高,果皮厚度适中,品质好,长势强,采收期长,建议春季种植,秋季尽量不要种植;金陵靓玉综合性状优于CK,早熟性好,果实硬度和果皮厚度均适中,果实商品性好;初恋番茄综合性状也优于CK,果实橘黄色,含糖量最高,口感偏甜,品质好;综合比较,粉娘樱桃番茄、金陵靓玉和初恋番茄3个品种较适合江阴地区春季设施栽培。     

丘陵山地区域双季晚稻机械化种植品种筛选研究

为了筛选适宜南方丘陵山地区域机械化高效生产的水稻品种,采用大田随机区组试验,研究了2个丘陵山地区域典型生态点不同供试晚稻品种机械化种植条件下的秧苗素质、茎蘖动态、产量与品种种植性状等。试验结果表明：低丘地区以品种‘Ⅱ优418’产量最高,达6.855 t/hm2;高丘地区以品种‘岳优9113’产量最高,达6.637 t/hm2。因此,在丘陵双季稻区晚稻机械化种植品种应具有分蘖力强、生育期短和抽穗整齐的特性。     

高效降解棉酚菌株的筛选鉴定及毒性试验

为了筛选一株能高效降解棉籽饼中棉酚毒素的菌株,以棉酚为唯一碳源,从棉田土壤中分离筛选对棉酚具有降解作用的菌株,得到具有较高降解活性的菌株M-9,其降解率达到94.74%,对其进行了菌株形态观察和生理生化鉴定并结合其16S rDNA序列,初步确定其为枯草芽孢杆菌(Bacillus subtilis)。通过对M-9菌株的脱毒效果研究表明,其具有降解棉籽饼中游离棉酚的能力,脱毒后棉籽饼中游离棉酚的含量降至33.18 mg/kg,符合中国国家标准饲料卫生标准规定(GB13078-2001)：饲料原料棉籽饼中游离棉酚含量≤1200 mg/kg。并进行毒性饲喂试验,从而确定菌株M-9处理后的棉籽饼粉对小白鼠无毒性。     

牛鲜粪转化为民用燃料的原料配方筛选

为开发一种实用、便于普及的鲜牛粪环保处理新技术,明确原料最佳配合比例,实现其资源循环再利用。采用正交试验,把奶牛鲜粪、煤粉、除臭吸附粘合剂为原料均匀混合处理,对牛鲜粪转化民用燃料技术的环保再利用进行了研究。结果表明：含水量较高的奶牛鲜粪最低利用比率可达40%,除臭吸附粘合剂最适合添加比率为11%时,将牛鲜粪中大量粪水和挥发性污染大气有害气体吸附固定,便于加工成多种形状的民用燃料加以再利用,具有强大的环保功能和鲜粪便循环再利用特点,对推动养牛业健康可持续发展具有重大意义。     

Fungicide modes of action and resistance in downy mildews

Among oomycetes, Plasmopara viticola on grape and Phytophthora infestans on potato are agronomically the most important pathogens requiring control measures to avoid crop losses. Several chemical classes of fungicides are available with different properties in systemicity, specificity, duration of activity and risk of resistance. The major site-specific fungicides are the Quinone outside inhibitors (QoIs; e.g. azoxystrobin), phenylamides (e.g. mefenoxam), carboxylic acid amides (CAAs; e.g. dimethomorph, mandipropamid) and cyano-acetamide oximes (cymoxanil). In addition, multi-site fungicides such as mancozeb, folpet, chlorothalonil and copper formulations are important for disease control especially in mixtures or in alternation with site-specific fungicides. QoIs inhibit mitochondrial respiration, phenylamides the polymerization of r-RNA, whereas the mode of action of the other two site-specific classes is unknown but not multi-site. The use of site-specific fungicides has in many cases selected for resistant pathogen populations. QoIs are known to follow maternal, largely monogenic inheritance of resistance; they bear a high resistance risk for many but not all oomycetes. For phenylamides, inheritance of resistance is based on nuclear, probably monogenic mechanisms involving one or two semi-dominant genes; resistance risk is high for all oomycetes. The molecular mechanism of resistance to QoIs is mostly based on the G143A mutation in the cytochrome b gene; for phenylamides it is largely unknown. Resistance risk for CAA fungicides is considered as low to moderate depending on the pathogen species. Resistance to CAAs is controlled by two nuclear, recessive genes; the molecular mechanism is unknown. For QoIs and CAAs, resistance in field populations of P. viticola may gradually decline when applications are stopped.     

Assessment of fungicide systemicity in wheat using LC-MS/MS

BACKGROUND: Systemicity is an important attribute of fungicides that is difficult to measure in early‐stage screening without labeling the compound with a radioisotope. A method of measuring translocation that does not require potent fungicidal activity or a radiolabel would guide identification of compounds with desirable attributes. RESULTS: The authors developed an analytical technique that mimics field application, using LC‐MS/MS to screen compounds for translocation in wheat leaves. The method sorted commercial and experimental fungicides appropriately into systemic and non‐systemic categories. A model using LC‐MS/MS data was equivalent to a lipophilicity model and superior to a water solubility model at predicting compound systemicity. CONCLUSION: Early‐stage compounds can be screened for systemicity on whole plants using LC‐MS/MS. Copyright © 2008 Society of Chemical Industry     

抗性筛选在抗生素高产菌选育中的应用

抗生素产生菌的产抗能力与其对抗生素的抗性之间具有一定的相关性,这为抗生素高产菌株的定向筛选提供了一种有效方法,即抗性筛选。综述了抗生素高产菌选育中抗性筛选的机理及其应用。