放牧对草原植物的影响

较全面的研究了内蒙古典型草原在不同放牧条件下的植物种类组成、生活型谱和种群特性及其生产力的变化,发现适度放牧下草原生产力具有补偿或超补偿性生产的现象,且草原植物多样性最高.     

Plant hazards.

A variety of plants, seeds, and nuts can cause toxicosis in small animals. Some plants are not as toxic as commonly believed by the general public. Conversely, plants or nuts that are consumed by human beings can be toxic to their pets. Most plant toxins do not have specific treatments or antidotes. As a result, treatment is often limited to decontamination plus symptomatic and supportive care.     

Plant derived veterinary vaccines

Infectious diseases remain one of the main causes of death and economic losses in animals despite the fact that prophylactic vaccination has been extremely successful in disease prevention. New effective viral, bacterial and parasitic vaccines are needed, but unfortunately production costs still remain prohibitive. In this respect plants can offer a valid alternative. Production of antigenic proteins in plants relies on a well developed and proven technology, several expression platforms are available and many different plant species can be utilized. Plant based veterinary vaccine studies have addressed protection issues in model animals and, more interestingly, some of them have examined the relevant challenge model in the specific species of interest. A general overview of the topic will be outlined together with a few selected promising examples.     

Plant derived veterinary vaccines

Infectious diseases remain one of the main causes of death and economic losses in animals despite the fact that prophylactic vaccination has been extremely successful in disease prevention. New effective viral, bacterial and parasitic vaccines are needed, but unfortunately production costs still remain prohibitive. In this respect plants can offer a valid alternative. Production of antigenic proteins in plants relies on a well developed and proven technology, several expression platforms are available and many different plant species can be utilized. Plant based veterinary vaccine studies have addressed protection issues in model animals and, more interestingly, some of them have examined the relevant challenge model in the specific species of interest. A general overview of the topic will be outlined together with a few selected promising examples.     

Linking Plant Spatial Patterns and Ecological Processes in Grazed Great Basin Plant Communities

Observational studies of plant spatial patterns are common, but are often criticized for lacking a temporal component and for their inability to disentangle the effect of multiple community-structuring processes on plant spatial patterns. We addressed these criticisms in an observational study of Great Basin shrub-steppe communities that have been converted to a managed grazing system of planted crested wheatgrass (Agropyron cristatum [L.] Gaertn.) stands. We hypothesized that intraspecific interference and livestock grazing were important community-structuring processes that would leave unique spatiotemporal signatures. We used a survey-grade global positioning system to quantify crested wheatgrass spatial patterns along a chronosequence of stands that differed only in time since planting (9–57 yr), as well as in a 57-yr-old grazing exclosure to examine pattern formation in the absence of grazing. Three replicate survey plots were established in each stand, and a total of 6 197 grasses were marked with a spatial error of ≤ 2 cm. The data were analyzed using L-statistics in program R, and hypothesis testing was conducted using Monte Carlo simulation procedures. We detected fine-scale regularity, frequently considered a sign of interference via resource competition, in all stands including the exclosure. Coarser-scale aggregation, which we attributed to the effects of prolonged grazing disturbance, was only detected in the oldest grazed stand. Our results suggest that interference acts over finer spatial and temporal scales than grazing in structuring these stands, reinforcing the importance of interference in semiarid communities. Analysis of exclosure data suggests that, in the absence of grazing, crested wheatgrass stands organize into a statistically regular pattern when primarily influenced by interference. In the presence of prolonged grazing, crested wheatgrass stands become more heterogeneous over time, likely a result of seedling mortality via disturbance by cattle.     

准噶尔荒漠3种典型植物群系植物多样性及其影响因素

以准噶尔荒漠3种典型植物群系为研究对象,通过野外调查取样和室内测定,并结合环境因子,分析比较准噶尔荒漠3种典型植物群系群落组成和多样性特征。结果表明:准噶尔荒漠3种典型植物群系共记录6科13属15种植物,物种多样性总体较低,藜科植物在荒漠植物中占比超过55%。在3种植物群系中,伊犁绢蒿群系的Shannon-wiener指数和Simpson指数最高,分别为1.09和0.56;白梭梭群系的Pielou指数和Simpson指数最低,分别为0.54和0.42;盐生假木贼群系的Pielou指数最高,为0.85。准噶尔荒漠植物群落物种组成和多样性受多种环境因子综合作用,影响伊犁绢蒿群系最主要的环境因子是土壤有机碳和全氮含量,影响白梭梭群系最主要的环境因子是年平均气温,影响盐生假木贼群系最主要的环境因子是年平均降水量和土壤pH值,在整个研究区域年平均气温、年平均降水量、纬度和土壤有机碳含量在所有环境因子中起主导作用。     

新型的植物抗生素——牛至油

牛至(Origganumvulgarelinn)俗称止痢草,是唇形科牛至属的一种多年生草本植物,主要分布在华北、西北至长江以南各地,主产于四川、云南、贵州等西南省份。牛至全草可提取挥发油,也可以用作香薷入药。它可用于治疗因暑热所引起的发热、头痛、身体困倦、呕吐、腹痛、腹泻等症状,也用于治疗急性胃肠炎、沙门氏菌感染等疾病。美国农业部的“植物化学和植物物种学”背景资料表明,牛至含有30多种抗菌化合物,是一种潜在的天然药物生长促进剂。1牛至油的抗菌机理研究发现,植物中的酚类化合物有天然的抗微生物作用,且酚类化合物的抗微生物作用最强。…     

植物提取物与微生态制剂

<正>化学合成类抗生素的推广使用带动了畜牧业的迅猛发展,极大地推动了规模化养殖的进程,使养殖成本不断降低。从以往的畜禽产品供不应求、城乡居     

人工湿地植物筛选的研究

为选择适应猪场废水处理中人工湿地的植物种,从野外采集12种植物,种在不同浓度猪场废水中作水培观察,并从耐污力、地上部生物量、根系、景观、易管理等5方面指标分别给予综合评定.筛选结果表明,风车草和香根草最适合用作猪场废水处理的人工湿地植物.风车草可以在COD 2 800 mg/L、NH3-N 390 mg/L以下猪场废水中生长,香根草可以在COD 1 300 mg/L、NH3-N 200 mg/L以下的猪场废水中生长.     

植物凝集素的研究进展

植物凝集素是一种能可逆地与单糖或寡糖结合的蛋白质,在自然界中广泛存在,是发现最早也是研究最为深入的凝集素。目前人们已经发现了几百种植物凝集素。它的最重要的营养特性就是在胃肠道中抵抗酶的降解,并和消化道表面的糖基受体结合,从而引起细胞和机体代谢发生改变。近年来对它的研究很多,甚至达到了基因水平。本文论述了它的分子结构,与糖结合的部位和方式,它的凝集性、抗营养性以及这些特性在科学研究和生产中的应用。作为饲料中的抗营养因子,还介绍了消除和检测方法。     

不同植物生长调剂对八宝景天株型和生理特性的影响

植物生长调节剂常被用来调节植物的生理和生态功能，提高植物种的综合优势。本研究通过5种商品植物生长调节剂细胞分裂素(Cytokinin，CTK)、赤霉素(Gibberellin，GA)、多效唑(Paclobutrazol，PP333)、矮壮素(Chlormequat chloride，CCC)及座果精(Pollination fruit essence，Pol)，以清水(CK)处理作为对照组，采用叶面喷施的方式，于盛花期测定八宝景天(Hylotelephium erythrostictum)的生长指标、叶片的叶绿素含量、光合参数、抗氧化特性。分析八宝景天对5种植物生长调节剂处理的响应，并运用模糊隶属函数法对处理效应进行综合评价，筛选对八宝景天株型和生理特性影响最优的植物生长调节剂。结果表明：5种植物生长调节剂对株高均存在促进作用，提高株高为2~6cm，对冠幅而言均出现了不同程度的抑制作用，冠幅直径平均缩小17~18cm；CTK与Pol可提高八宝景天叶片的叶绿素含量；Pol,PP333和CCC三种植物生长调节剂提高植物光合作用能力；CCC处理下植物内体的保护酶活性及丙二醛含量相较于CK降低，说明CCC处理下的八宝景天抗逆境、抗衰老能力最强。在Pol,CCC与PP333处理下，八宝景天光合作用增强。根据模糊隶属函数值综合评价得知，CCC处理下的八宝景天光合生理状况最具优势。