践踏胁迫对两种暖地型草坪草叶片形态及生理的影响

通过测定践踏胁迫下野生假俭草和结缕草2种草坪草叶片的几项生理指标,初步探讨了在践踏胁迫下叶片的超氧化物歧化酶活性、可溶性总糖含量、脯氨酸含量、相对电导率和叶绿素含量等生理指标的变化特征.结果表明,1)践踏胁迫下假俭草和结缕草草层厚度、叶片长度和宽度均比对照有显著的减少.2)践踏胁迫下结缕草和假俭草的相对电导率、可溶性总糖、脯氨酸含量均显著高于对照;SOD酶活性要低于对照.3)践踏胁迫下可溶性总糖含量、脯氨酸含量、叶绿素和类胡萝卜素的含量均为:假俭草>结缕草.综合评价,通过形态和生理指标分析假俭草叶片耐践踏能力大于结缕草.     

践踏胁迫对上海“JD-1结缕草”生长及生理的影响

采用人工践踏方式对上海“JD-1结缕草”草坪进行践踏胁迫试验,研究了不同程度践踏胁迫对结缕草生长、生理的影响。结果表明:(1)随践踏肘期延长,重度践踏草坪草株高、叶长、密度、地上生物量和绿叶率均显著低于对照和轻度践踏(P<0.05);而中度与轻度践踏之间的株高、叶长、密度、地上生物量差异不明显;(2)中度和重度践踏的叶片脯氨酸和丙二醛含量、叶片细胞膜透性明显高于对照,重度践踏的群体光合速率则明显低于对照和轻度践踏处理(P<0.05);(3)对于上海“JD-1结缕草”草坪,若采用合理的养护管理措施如适时灌溉、修剪等,中等践踏强度可以维持较好的坪用质量。     

水分胁迫对结缕草种群特征和生理特性的影响

 采用大田试验,研究了“ＪＤ-１”结缕草在水分胁迫下的种群特征和生理特性变化。结果表明,水分胁迫能明显抑制结缕草的生长发育,结缕草也能通过自身生理生化调节来减弱由水分胁迫带来的伤害。在水分胁迫下,水分胁迫区结缕草密度、株高和生物量低于无水分胁迫区,且随水分胁迫的增加而明显降低。结缕草叶片相对电导率、游离脯氨酸含量和丙二醛含量在无水分胁迫区随试验期的延长呈缓慢增大的趋势;而在轻度和重度水分胁迫区随水分胁迫时间的延长呈波动状变化。复水期内结缕草密度、株高和生物量明显增大,水分胁迫区密度和生物量明显大于无水分胁迫区;结缕草叶片相对电导率、游离脯氨酸含量和丙二醛含量明显低于无水分胁迫区,且轻度和重度水分胁迫区各指标值差异不显著。     

干旱胁迫和施氮对结缕草种群特征和生理特性的影响

分析了氮、水分与上海结缕草(Zoysia japonica cv. Shanghai)生长之间的相互关系,为上海结缕草草坪科学施肥和灌溉提供依据。试验选择干旱胁迫和施氮2个因素,各设置3个水平,结果表明:轻度干旱胁迫+中氮组合处理的草坪品质非常好,草坪密度和地上生物量高于或接近无干旱胁迫+中氮组合处理,且显著好于轻度干旱胁迫的其他处理和重度干旱胁迫的全部处理(P0.05);高氮处理的结缕草株高在同一干旱水平中均明显高于其他处理(P0.05)。在相同干旱胁迫下,施氮后第19天,结缕草叶片的相对电导率、游离脯氨酸含量和可溶性糖含量均随施氮量的增加而呈现升高的趋势;与此相反,施氮后第41天时,则呈现出随施氮量的增加而降低的趋势;随着干旱胁迫程度的增加,叶片丙二醛含量呈现增加的趋势。研究结果表明,适度的干旱胁迫和适量的氮肥有助于维持上海结缕草较好的坪用品质。     

不同水分胁迫下水杨酸对分枝期扁蓿豆生长及光合生理的影响

为明确水杨酸对扁蓿豆分枝期抗旱性的调控作用,采用盆栽试验研究正常供水(80%田间持水量)、轻度水分胁迫(60%田间持水量)、中度水分胁迫(40%田间持水量)以及重度水分胁迫(20%田间持水量)条件下,不同浓度[0(对照),0.02,0.10,0.50,2.50 mmol/L]水杨酸处理对扁蓿豆分枝期生长、抗性生理及光合特性的影响。结果表明,轻度、中度水分胁迫下,0.10 mmol/L水杨酸显著提高了叶片相对含水量、叶绿素含量、可溶性蛋白含量,同时使超氧化物歧化酶(SOD)、过氧化物酶(POD)、过氧化氢酶(CAT)活性以及叶片光合速率(Pn)、气孔导度(Gs)得到显著提高,而气孔限制值(Ls)显著降低;重度水分胁迫下,0.50 mmol/L水杨酸显著提高了株高、一级分枝数、叶面积、叶片相对含水量、叶绿素含量、游离脯氨酸含量、可溶性蛋白含量,同时SOD、POD、CAT活性以及叶片Pn、Gs、水分利用效率(WUE)显著提高,而使电导率、丙二醛(MDA)含量以及LS显著降低。可见,适宜浓度水杨酸可以改善干旱胁迫下扁蓿豆分枝期的生长,提高其抗旱能力。     

氮磷钾复合肥对上海"JD-1结缕草"草坪耐践踏性的影响

通过践踏器模拟践踏,研究氮、磷、钾复合肥对践踏胁迫下上海"JD-1结缕草"草坪耐践踏性的影响,结果表明:非践踏区和践踏区内,结缕草Zoysia japonica的地上生物量和绿叶率随着复合肥用量的增加而增加.践踏胁迫下,50 g/m2处理的地上生物量和绿叶率显著高于不施肥(P＜0.05);施肥可使践踏结缕草叶片中游离脯氨酸含量增加,丙二醛含量和细胞膜透性降低,光合作用增强,从而,提高了上海"JD-1结缕草"的耐践踏性.氮、磷、钾复合肥能够有效减轻践踏对结缕草的胁迫程度,提高结缕草草坪的耐践踏性.     

硅对磨损胁迫下狗牙根和结缕草表观质量与生理代谢的影响

为探究外源硅对磨损胁迫下的暖季型草坪草表观质量和生理代谢的影响,本研究以狗牙根属的Tifgreen杂交狗牙根和普通狗牙根,结缕草属的兰引Ⅲ号结缕草和青岛结缕草为对象,设置对照和施外源硅两组,进行不磨损处理和磨损处理,并测量其表观质量指标和生理指标。结果表明,外源硅可以通过促进狗牙根和结缕草的分蘖和生长,以及降低叶片丙二醛、游离脯氨酸含量和相对电导率,同时提高叶片超氧化物歧化酶活性和可溶性糖含量,一定程度上减轻磨损胁迫对狗牙根和结缕草生长的影响。综合比较表观质量指标和生理指标的变化,外源硅能够一定程度上提高狗牙根和结缕草的耐磨损性,其中对提高狗牙根的耐磨损性效果更好。     

滞绿剂和践踏对马尼拉草坪冬季保绿能力的影响

在践踏和非践踏条件下,研究了滞绿剂对马尼拉结缕草秋冬枯黄的调控效应。结果显示:滞绿剂处理能显著延缓马尼拉结缕草的枯黄进程,保绿效果随着滞绿剂剂量的增加而增大;与对照相比,滞绿剂处理显著增加了草坪密度、单茎绿叶数、单茎鲜重和叶绿素含量,降低了枯叶率和叶片电导率;对照区践踏显著降低了草坪高度、密度和单茎绿叶数,加速了草坪的枯黄进程;1000和200 g/hm²滞绿剂处理可以逆转践踏的负面作用,草坪密度、单茎绿叶数和叶绿素含量显著高于非践踏处理,而枯叶率和叶片电导率则显著低于非践踏处理,表明高、中剂量的滞绿剂处理增加了结缕草的耐践踏能力。     

不同盐浓度下3种结缕草的耐盐性比较研究

以大穗结缕草、沟叶结缕草和日本结缕草为试材,研究了不同浓度NaCl(0.20%,0.40%,0.60%,0.80%)处理40 d后对3种草坪草叶片中保护酶(POD,SOD,CAT)活性、丙二醛、脯氨酸、叶绿素及可溶性蛋白含量的影响,以确定各自的耐盐性强弱。结果表明,随盐浓度增加,3种草坪草叶片中的保护酶活性、丙二醛、脯氨酸含量呈上升趋势。在0.80%盐浓度下,大穗结缕草叶片中的保护酶活性较高而丙二醛、脯氨酸含量较低;低盐浓度下(<0.40%),3种草坪草叶片的叶绿素含量、可溶性蛋白含量随盐浓度升高而升高,高盐浓度下(>0.60%),随盐浓度升高而下降。在0.80%盐浓度下,大穗结缕草叶片的叶绿素及可溶性蛋白含量较高且下降值较小。表明大穗结缕草具有较高的耐盐性。     

假俭草和结缕草在昆明地区的抗逆性及草坪质量比较

假俭草(Eremochloa ophiuroides)和结缕草(Zoysia japonica)是我国分布广泛的野生暖季型草坪草,为了充分了解在昆明的适应性,在干旱持续90d时,从草坪质量及叶绿素、丙二醛、游离脯氨酸、可溶性糖等方面进行了综合比较。试验结果表明:在持续干旱下,游离脯氨酸、可溶性糖在假俭草中含量显著高于结缕草(P 0.05),叶片相对含水量(LRWC)和叶绿素含量显著低于结缕草(P 0.05),而丙二醛的含量差别不明显。从外观质量来看,假俭草和结缕草草坪在冬季的综合评分均大于5分,且差异不明显(P 0.05),草坪外观质量可以接受。从生理指标的差别来看,假俭草的抗寒性优于结缕草,抗旱性不如结缕草,由于昆明地区旱季缺水的时间较长,在管理粗放的条件下建议选用结缕草。     

H9N2亚型禽流感病毒传播途径特性的比较及其表面基因序列分析

选择中国大陆最早分离的H9N2亚型禽流感病毒(avian influenza virus,AIV)A/Chicken/Guangdong/SS/94(H9N2)(缩写为SS株)和1998年大流行时期分离的H9N2亚型AIVA/Chicken/Shanghai/F/98(H9N2)(缩写为F株)为研究对象,对其在SPF鸡体内的复制能力和传播途径特性比较后发现,F株在4周龄SPF鸡气管中的复制能力高于SS株,F株可以经气溶胶传播途径传播,SS株不能经气溶胶传播途径传播;利用反转录-聚合酶链反应(RT-PCR)方法获取F株和SS株的HA和NA基因的cDNA,序列分析得知,F株和SS株的HA和NA基因的同源性分别是96.6%和98.1%;HA基因的裂解位点氨基酸序列都是PARSSR↓GL,但有5个氨基酸的差异,即166位N(F)→D(SS)、198位A(F)→V(SS)、217位V(F)→I(SS)、335位G(F)→R(SS)、504位L(F)→S(SS);2株病毒的NA基因在63~65位都存在氨基酸缺失,但在NA基因红细胞吸附位点的氨基酸序列不同,分别是IKKDSRSG(F)和IKEDLRSG(SS)。F株和SS株的传播特性差异是否与其表面基因序列有关,有待进一步研究。     

禽类的起源、演化及我国主要家禽品种类型与分布

家禽是重要经济价值动物.本文从禽类种群进化学说出发,简介了禽类的起源、演化、动物学分类和家禽的驯化(养)与品种的形成,并对我国主要家禽(鸡、鸭、鹅)地方品种和培育品种(配套系)的分布与类型作了描述,以期为研究我国家禽起源系统,保护与利用我国家禽品种,促进家禽生产可持续发展提供参考.     

一起猪链球菌病和伪狂犬病的混合感染的诊治

近年以来,由于市场因素的刺激,生猪的存养量大幅上升,再加上由于流通环节较多,流通非常频繁,流通距离越来越远。这对繁荣经济,增加养殖效益起了重要的推动作用,但也同时给疾病的感染和传播创造了有利条件,给猪病的防治带来了困难。有的猪场感染了传染病后,由于治疗不及时不得法,而造成了惨重的经济损失。2008年7月中旬,我街道一养猪户因盲目从外地购进中猪,发生猪病疫情,引起猪只连续死亡,造成一定的经济损失。根据流行病学、临床症状、剖检变化和实验室诊断,诊断该病为猪链球菌病和猪伪狂犬病混合感染,现报告如下。     

秋冬季预防和治疗虫媒性传染病鸡白冠病和鸡痘

１前言１．１鸡白冠病鸡白冠病是由卡氏住白细胞原虫寄生于鸡的红细胞和单核细胞而引起的鸡的贫血性疾病。吸血昆虫蚋和库蠓叮咬鸡引起传播，是主要的传播媒介，一般在夏末和秋季多发，由于夏季降雨量较大，部分沟渠积水，库蠓和蚋多孳生，因此在多雨水涝的年份发病率明显增高。１９９８年中国从南到北发生洪涝灾害，吸血昆虫的孳生格外严重，出现了一个白冠病多发年，而后两年发病稍轻，并有地区性，今年８月中旬以来白冠病的发病呈抬头趋势，有一定的死亡率，对蛋鸡产蛋率也会引起一定程度的降低，应引起养鸡户的重视。１．２鸡痘鸡痘也是…     

种鹅矛形剑带绦虫与背孔吸虫混合感染的诊治

2005年9月份,大庆市红岗区个体养鹅专业户送检6只病死的5月龄左右隆昌鹅和长白鹅,经过实验室诊断确诊为矛形剑带绦虫与背孔吸虫混合感染。矛形剑带绦虫属膜壳科     

Evaluation of lysozyme and lactoferrin in lacrimal and other ocular glands of bison and cattle and in tears of bison

OBJECTIVE: To evaluate lactoferrin and lysozyme content in various ocular glands of bison and cattle and in tears of bison. SAMPLE POPULATION: Tissues of ocular glands obtained from 15 bison and 15 cattle and tears collected from 38 bison. PROCEDURE: Immunohistochemical analysis was used to detect lysozyme and lactoferrin in formalin-fixed, paraffin-embedded sections of the ocular glands. Protein gel electrophoresis was used to analyze ocular glands and pooled bison tears by use of a tris-glycine gel and SDS-PAGE. Western blotting was used to detect lactoferrin and lysozyme. RESULTS: Immunohistochemical staining for lactoferrin was evident in the lacrimal gland and gland of the third eyelid in cattle and bison and the deep gland of the third eyelid (Harder's gland) in cattle. Equivocal staining for lactoferrin was seen for the Harder's gland in bison. An 80-kd band (lactoferrin) was detected via electrophoresis and western blots in the lacrimal gland and gland of the third eyelid in cattle and bison, Harder's glands of cattle, and bison tears. An inconsistent band was seen in Harder's glands of bison. Lysozyme was not detected in the lacrimal gland of cattle or bison with the use of immunohistochemical analysis or western blots. Western blots of bison tears did not reveal lysozyme. CONCLUSIONS AND CLINICAL RELEVANCE: Distribution of lactoferrin and a lack of lysozyme are similar in the lacrimal gland of cattle and bison. Differences in other tear components may be responsible for variability in the susceptibility to infectious corneal diseases that exists between bison and cattle.     

Shape and size of teeth of dogs and cats-relevance to studies of plaque and calculus accumulation

Crown width, height and buccal surface areas were measured on heads or skulls of four dogs and four cats, and were compared with similar measurements on models of human dentition. Buccal surface area variability was greater in dogs and cats than in humans, and teeth of cats were smaller. Horizontal (gingival and occlusal halves) and vertical (mesial, middle, and distal thirds) buccal surface area variability was also greater in canine and feline teeth compared with human teeth. This increased variability suggests the need for testing of reliability and repeatability of scoring when using plaque and calculus indices based on horizontal or vertical segmentation. Buccal surface area variability between teeth also prompts questioning the validity of equal weighting of smaller, irregularly-shaped teeth when calculating a mean mouth score. Whether equal or more reliable results would be obtained from scores of whole teeth in comparison with segmentation indices used currently has yet to be determined.     

Description and classification of abnormal cercariae of Schistosoma mattheei and a method of concentration and collection

Over a period of about 12 years, 30 abnormal Schistosoma mattheei cercariae were found among a total of approximately 2.8 million examined. Initially seven were recovered from about 1.02 million (0.0007%), which were examined individually while being counted with the aid of a stereoscopic microscope. Subsequently, on the strength of relatively high percentages of abnormal individuals recovered when counting cercariae that failed to penetrate into oxen, it appeared that the morphologically abnormal cercariae were unable to swim and would mostly sediment out of a suspension while most of the normal cercariae would remain swimming. This surmise is supported by recovery of 23 morphologically abnormal cercariae (0.001%) from about 1.8 million, by examining the sediment after the cercarial suspension had been left standing undisturbed in glass measuring cylinders. The abnormalities ranged from aberrant tails only (e.g. an underdeveloped tail, or different degrees of schism) or aberrant heads only, to abnormalities of both the heads and tails. A suggested schematic classification of abnormal cercariae is presented. A young, adult hamster was exposed to eight S. mattheei cercariae with complete schism of the shaft of the tail, by pipetting the cercariae onto the shaved abdominal skin of the anaesthetised animal. Two underdeveloped females were subsequently encountered in squash preparations of the liver when the hamster was killed for worm recovery 10 weeks after infection, thus showing that some of the abnormal cercariae were viable. A method is also described for killing and fixing cercariae while retaining some of the shining brilliance of live cercariae, without them becoming shrivelled, granular and semi-opaque, as occurs when cercariae die spontaneously or are killed with heat. This is apparently the first report of abnormal cercariae of S. mattheei. In addition, a method of concentrating abnormal cercariae after emergence from a snail, a schematic classification of abnormal cercariae and a method for killing and fixing cercariae while retaining much of the shiny brilliance of live cercariae are also reported for the first time as far as is known.