一株海洋放线菌的分离鉴定及活性研究

从大连海域20~30 m深处生长的海绵中分离到一株有很高抗菌活性的链霉菌D164。根据培养和显微形态、生理生化数据、16S rRNA基因序列数据分析,菌株D164鉴定为娄彻氏链霉菌(Streptomyces rochei)。对菌株D164发酵产物进行抗农业病原菌、杀虫和除草活性检测,结果表明,菌株D164发酵产物具有很高的抗农业病原菌活性,同时又具有很高的杀虫和除草活性,其活性化合物值得进一步研究。     

Diversity and Community Quantitative Characteristics ofFloor Lichen in Yaoluoping National NatureReserve of Anhui,China

Twenty nine quadrats belonging to various habitats were sampled in Yaoluoping National Nature Reserve, lichen species in each quadrat were identified and the lichen coverage of each quadrat was measured, combined with several environmental indices, with the purpose of understanding the lichen distributing pattern and community quantitative characteristics. Factor analysis was used to appraise relationships among ecological factors, cluster analysis and Spearman rank correlation coefficient test were employed for ordination and Fisher’s exact test was applied to evaluate interspecific correlation. Factor analysis showed that the number of species decreased as the altitude increased, and there was significant positive correlation between dominant species quantity and coverage (P=0.034), very significant positive correlation between humidity and habitat type (P=0.001). Based on cluster analysis data, twenty nine quadrats were divided into 5 types of association. Fisher’s exact test indicates 10 species pairs were very significant positive association and four species pairs significant positive, but no species pair was negative significant association. Fisher’s exact test demonstrated that the competition between the species was low.     

湖羊6号染色体微卫星标记多样性与产羔数的关系

选择位于绵羊6号染色体上FecB基因紧密连锁的6个微卫星标记, 即LSCV043、BMS2508、GC101、300U、Bulge5和471U, 分析其在湖羊中的遗传多样性以及和产羔数的关系。结果表明, 6个微卫星位点均属多态性位点, 共检测到34个等位基因、53种基因型。LSCV043、BMS2508和300U属高度多态位点, 其多态信息含量分别为0.6674、0.6035和0.5615。对不同基因型群体的产羔率进行统计分析, LSCV043基因型为107 bp/123 bp所对应的总体产羔数明显高于110 bp/123 bp基因型群体所对应的产羔数(P<0.05); BMS2508基因型为154 bp/154 bp、154 bp/170 bp和154 bp/200 bp所对应的群体第一胎产羔数明显高于170 bp/170 bp所对应的产羔数(P<0.05), 基因型170 bp/170 bp的群体总体产羔数均低于该位点的其他基因型(P<0.05); 其他位点各基因型之间产羔数均无显著差异。     

闽江河口湿地植物氮磷吸收效率的季节变化

以闽江河口湿地土著种芦苇与入侵种互花米草为研究对象,测定了二者地上生物量和氮、磷吸收效率.结果表明：芦苇和互花米草地上生物量的季节变化呈典型的单峰值曲线,芦苇夏季地上生物量最大,达到2195.33 g·m^-2,互花米草则秋季最大,达到3670.02 g·m^-2;不同季节芦苇和互花米草氮、磷吸收效率均呈单峰值曲线,芦苇氮、磷吸收效率分别在夏季和秋季达到最高(21.06 和1.12 g·m^-2),互花米草均在秋季达到峰值(26.76和3.23 g·m^-2);芦苇和互花米草的氮吸收效率极显著大于磷(P<0.01),且互花米草的氮、磷吸收效率显著大于芦苇(P<0.05);植物N/P、C/N和C/P对植物氮、磷吸收效率有一定指示意义.     

嫁接对低温弱光下甜椒幼苗光合作用的影响

以‘卫士’和‘部野丁’为砧木,以‘赤峰特选’为接穂进行嫁接,在光照培养箱内对甜椒自根苗和嫁接苗进行低温(8 ℃/ 5℃)弱光(100 μmol·m^-2·s^-1)处理,处理7 d后在正常条件（25 ℃/18 ℃,PFD 550～600 μmol·m^-2·s^-1）下恢复3 d,研究低温弱光下甜椒嫁接苗和自根苗气体交换参数、羧化效率和荧光参数等的变化.结果表明：低温弱光胁迫3 d时,甜椒幼苗叶片的光合速率（P_n）、气孔导度（G_s）和羧化效率（CE）均下降50%以上,之后P_n、G_s趋于平稳,CE持续下降;胞间CO₂浓度（C_i）呈先下降后上升趋势.低温弱光下,甜椒幼苗的暗下最大光化学效率(F_v/F_m)、光下实际光化学效率（Ф_PSⅡ）及电子传递速率（ETR）显著降低,初始荧光(F_o)有所升高,表明其光合机构受到一定伤害,但处理结束3 d后基本恢复.与自根苗相比,嫁接苗在各处理阶段的P_n、G_s、CE、Ф_PSⅡ、F_v/F_m和ETR都有不同程度的提高,F_o明显降低.可见,嫁接可显著提高甜椒幼苗的光合功能,减轻低温弱光对其光合作用的影响.     

氮素添加对科尔沁沙质草地物种多样性和生产力的影响

物种多样性和生产力是生态系统结构和功能的重要指标.以科尔沁沙质草地为对象,通过对其进行不同梯度的氮素添加处理,研究氮素添加对沙质草地生态系统物种组成、物种多样性和生产力的影响.结果表明：氮素添加改变了群落物种组成和群落中的优势种,使植被的高度和盖度增加,植被的透光率减小;随着氮素水平的增加,群落中物种丰富度减小,物种多样性降低;不同水平的氮素添加均显著增加了(P<0.01)群落地上生物量;物种丰富度与植被透光率呈线性正相关(P<0.01),与植被盖度呈线性负相关关系(P<0.01),说明长期的氮沉降与人为氮素输入将影响沙地生态系统的物种组成、物种多样性以及生产力.     

Polymorphism of FecB Gene in Nine Sheep Breeds or Strains and Its Effects on Litter Size, Lamb Growth and Development

Nine sheep breeds or strains, including 615 individuals were screened with forced PCR RFLP method for the FecB gene to study the polymorphism and its effects on litter size, body weight and body size. Results showed that the polymorphism frequencies of FecB gene were significantly imbalanced in these breeds or strains. The Hu sheep were all homozygous carriers of FecB gene(BB). In the Chinese Merino prolific meat strain, the genotype frequencies of BB, B+ and ++ were 51%, 30% and 19%, respectively, whereas all the other flocks had only the wild-type (++) genotype. Results within the Chinese Merino prolific meat strain showed that the mean litter size of ewes with genotype BB and B+ were 2.8 (±0.74) and 2.3 (±0.63) (P<0.05). whereas ++ genotype ewes had a litter size of only 1.2 (±0.68) (P<0.01). At day 90 after birth, the body weights of BB/B+ genotype lambs were higher than that of ++ genotype lambs (18.6±3.70 kg. 18.0±3.71 kg vs 15.6±2.22 kg, P<0.05). In addition, the heart girth and chest width of BB/B+ genotype lambs were significantly longer than those of the ++ lambs (P<0.05). No significant differences were observed in either body weight or body size at day 120. Litter size at first lambing from Hu at Natural Source Conservative Region was found to be significantly higher than that from the other two regions sampled (P<0.05). In addition to the additive effect on litter size, these findings showed for the first time that the FecB gene had a positive effect on early postnatal body growth.     

CKLF1作为缺血性脑卒中治疗的潜在靶点

缺血性脑卒中是一种血液循环障碍疾病,可导致严重的神经功能缺损.卒中病人中约有87％的病例为缺血性卒中.神经炎症是中风损伤的主要病理状态之一.CKLF1是2001年发现的非经典CC型趋化因子,对单核细胞、中性粒细胞和淋巴细胞表现出很强的趋化活性.CKLF1在胎儿大脑中含量最高,但在健康成人阶段不存在.越来越多的证据表明,...     

灰胸竹鸡血清某些生化参数的测定

运用自动生化分析仪测定了21只野生成年灰胸竹鸡的血液生化参数,结果表明:雌性在总蛋白、白蛋白和球蛋白水平,以及谷丙转氨酶活性均高于雄性(P>0.05),雌性白蛋白/球蛋白却较雄性低;同样,雌性个体的总胆红素、总胆固醇和甘油三酯的含量分别较雄性高8.33%、23.08%和15.38%(P>0.05).提示雌性个体的代谢较雄性个体要强,可为深入探讨竹鸡的机体代谢规律提供资料.     

D-半乳糖致衰老模型大鼠肝肾功能和自由基代谢与中药的干预作用

目的观察D-半乳糖致衰老模型大鼠血糖血脂、肝肾功能和自由基代谢的变化,探讨中药的干预作用及其抗衰老的机制。方法大鼠每日皮下注射D-半乳糖,连续造模7周,建立大鼠衰老模型,造模同时,用抗衰老片和首乌延寿片进行干预,测定试验大鼠的血糖血脂、肝肾功能和SOD、MDA、Na＋-K＋-ATPase和Ca＋＋-Mg＋＋-ATPase等自由基代谢指标。结果造模7周后,模型对照组衰老大鼠TG、BUN明显升高（P〈0.05,P〈0.01）,AST、ALP、CREA呈上升趋势（P〉0.05）,肝、肾组织SOD活性明显降低（P〈0.05）,肾组织MDA含量明显升高（P〈0.05）,肝组织Na＋-K＋-ATPase和Ca＋＋-Mg＋＋-ATPase活性均显著降低（P〈0.05,P〈0.01）;给予抗衰老片和首乌延寿片后,衰老大鼠TG、AST、BUN、CREA和UA均显著降低（P〈0.05,P〈0.01）,肝、肾组织MDA含量显著降低（P〈0.05）,SOD活性显著升高（P〈0.05,P〈0.01）,肝组织Na＋-K＋-ATPase和Ca＋＋-Mg＋＋-ATPase活性均显著升高（P〈0.01）。结论D-半乳糖致衰老大鼠模型的血脂上升、肝肾功能异常和抗脂质过氧化的能力下降;给予抗衰老片和首乌延寿片后,可有效改善衰老大鼠的糖脂代谢和肝肾功能,提高肝肾组织的抗脂质过氧化的能力,提示中药的抗衰老作用可能与其抗氧化作用有关。