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干旱胁迫对六种观赏草枯叶率及生理指标的影响 总被引：3，自引：0，他引：3
在南京自然气候、土壤条件下,对花叶蒲苇、香茅、红叶白茅、花叶芒、斑叶芒和花叶虉草六种园林常见观赏草进行了外观形态及生理生化对干旱的响应研究。结果表明:随着干旱胁迫的加重,6个草种的叶片相对含水量、叶绿素含量呈下降趋势,枯叶率、叶片细胞质膜透性、丙二醛含量均呈上升趋势,超氧化物歧化酶(SOD)活性呈先上升后下降的变化趋势。耐旱性强的草种叶片相对含水量、叶绿素含量下降较慢,枯叶率、细胞质膜透性、MDA含量上升幅度明显低于耐旱性弱的草种。相关分析表明,除SOD活性外,其余指标之间的相关性均显著,表明枯叶率可以作为评价观赏草耐旱性的形态指标。综合评价六种观赏草的耐旱性为花叶蒲苇>香茅>斑叶芒>花叶芒>花叶虉草>红叶白茅。 相似文献
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以物候期、形态特征、越夏性、越冬性及抗病虫害能力为观测指标,系统研究了19种多年生观赏草在成都地区的适应性表现。结果表明,蒲苇属、芒属、狼尾草属等13种暖季型观赏草中除蒲苇、矮蒲苇、花叶蒲苇四季常绿外,其余草种均在11月末枯黄,次年3月初返青;除白美人狼尾草每年6月和10月2次开花外,其余草种只开花1次且花期均集中在7～11月,花期较长。蓝羊茅、细茎针茅、金叶苔草、细叶苔草、金边阔叶麦冬和黑麦冬6种冷季型观赏草中,细茎针茅和蓝羊茅夏季休眠,其余草种四季常绿;黑麦冬不开花,其余草种花期均集中在3～5月,花期较短。在成都地区19种观赏草除蓝羊茅越夏性差、死亡率高外,其余草种均能适应成都地区的气候环境。 相似文献
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13种观赏草在南京地区夏秋两季观赏价值的灰色关联分析 总被引：6，自引：1，他引：5
观赏草作为一种新型的植物造景材料,日益成为城市园林绿化的重要组成部分,对其观赏性的综合评价也变得尤为重要。以成活率、生长状况、植株观赏价值、花序美感及叶片颜色为评价指标,采用灰色关联分析对13种多年生观赏草夏秋两季的观赏价值进行了综合评价。结果表明:狼尾草Pennisetum alopecu-roides、红叶白茅Imperata cylindrical cv.‘Red Baron’、花叶虉草Phalaris arundinacea var. picta、香茅Cymbopogon citratus、花叶蒲苇Cortaderia selloanacv.‘Silver Comet’、金叶苔草Carex oshimensiscv.‘Ver-gold’和欧根金线蒲Acorus gramineus cv.‘Ogon’7种观赏草观赏价值较高,且夏秋两季观赏价值变化不大;斑叶芒Miscanthus sinensis cv.‘Zebrinus’、蒲苇C.selloana、细叶芒M.sinensiscv.‘Gracillimus’、花叶芒M.sinensis cv.‘Variegatus’4种观赏草秋季花序盛开,观赏价值较夏季有较大幅度的提高;蓝羊茅Festucaovina var. glauca叶片银蓝色,叶形色泽美观,初夏观赏价值较高,但随着时间的推进出现枯黄现象导致其观赏价值明显降低;细茎针茅Stipa tenuissima夏秋两季的观赏性评价均较低,不适合用于夏秋两季南京地区的景观绿化。 相似文献
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干旱胁迫对4种观赏草枯叶率及生理指标的影响 总被引：1，自引：0，他引：1
为了解观赏草的抗旱机制,在盆栽控水条件下,对红叶白茅(Imperata cylindrical‘Red Baron’)、花叶芒(Miscanthus sinensis‘Variegatus’)、斑叶芒(Miscanthus sinensis‘Zebrinus’)和花叶虉草(Phalaris arundinaceavar.picta)4种观赏草进行了外观形态及生理生化响应研究。结果表明:随着干旱胁迫的加剧,4个草种的土壤含水量、叶片相对含水量(RWC)均呈下降趋势,枯叶率、叶片细胞质膜透性(REC)、丙二醛(MDA)含量、脯氨酸(Pro)含量均呈上升趋势;超氧化物歧化酶(SOD)活性和可溶性蛋白含量均呈先上升后下降的变化趋势。抗旱性强的草种RWC下降最慢,枯叶率、REC,以及MDA和Pro含量上升幅度低于抗旱性弱的草种。综合评价4种观赏草的抗旱性顺序为斑叶芒>花叶芒>红叶白茅>花叶虉草。 相似文献
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南京地区观赏草的适应性和利用价值初步评价 总被引：10，自引：2，他引：8
对3科17属30种(27份从国外引进栽培的观赏草和3份南京本土引种的材料)观赏草外部性状、物候期、抗寒性、耐热性、抗病虫性和整株、花序、叶的观赏性进行跟踪观测,评价并分析其在南京地区的适应性和观赏价值,分成A-E 5个等级.A级:细茎针茅Nassella tenuissima、矮蒲苇Cortaderia selloana 'Pumila',具有很好的观赏性和南京地区适应能力,完全适合在南京地区推广;B级:紫田根Saccharum arundinaceum、柳枝稷Panicum virgatum 'Rehbraun'、发状苔草Carex albula、皱苞苔草C. chungii C.P.Wang、蓝灰石竹Dianthus gratianopolitanus 'Bath's pink'、甜茅S.ravennae、狼尾草Pennisetum、棕榈叶苔草C. muskingumensis、歌舞芒Miscanthus sinensis 'Cabaret'、芦竹Arundo donax、劲芒M. sinensis 'Strictus'、小盼草Chasmanthium latifolium,有较好观赏性和地区适应性,可以在南京地区推广;C级:宽叶苔草C.flacca、Sorghastrum nutans、金边苔草C. oshimenis 'Gold Strike'、巨针茅Stipa gigantea、斑叶苔草C.variegated、遍生芒M.sinensis 'Cosmopolitan'、花叶虉草Phalaris arundinacea 'Picta'、晨光芒M.sinensis 'Morning light'、拂子茅Calamagrostis overdam,具有一定的观赏价值,但个别指标评分低,应用时增加保护措施;D级:桔红苔草C.testacea、红叶白茅Imperata cylindrica 'Red Baron'、褐红苔草C.comans 'Bronze'、球茎燕麦Arrhenatherum elatius subsp.Bulbosum、花叶芦竹Arundo donax 'Variegata'、画眉草Eragrostis spectabilis,关于花序表现的几个指标评价均较低,影响总体评价,可以在南京地区推广但不适合观花,可以作为观叶植物;E级:金黄蒲苇Cortaderia selloana 'Aureolineata'各项指标评分都较低,不适合在南京地区推广. 相似文献
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干旱胁迫对4种观赏草枯叶率及生理指标的影响 总被引：2，自引：0，他引：2
以红叶白茅(Imperatacylindrica‘Red Baron’)、花叶芒(Miscanthus sinensis‘Variegatus’)、细茎针茅(Stipatenuissi ma)和金叶苔草(Carexoshi mensis‘Evergold’)4种观赏草为试验材料,进行干旱胁迫处理,分析4种观赏草枯叶率、叶片相对含水量、叶片细胞膜透性、丙二醛(MDA)含量、超氧化物歧化酶(SOD)活性、可溶性蛋白含量、叶绿素含量的变化。结果表明,随着干旱胁迫时间的推进,4种观赏草的细胞膜透性、MDA含量和可溶性蛋白含量不断增加,与枯叶率的增加呈显著正相关;叶片相对含水量、叶绿素含量不断降低,与枯叶率的增加呈显著负相关。比较形态和生理指标后,发现4种观赏草的抗旱性依次为金叶苔草细茎针茅花叶芒红叶白茅。 相似文献
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国外优良草坪草在中国的引种适应性研究 总被引：14，自引：5，他引：9
为在中国不同的气候和土壤环境中寻找最适应当地的草坪草种及品种 ,从国外 14家种子公司引入 131个草坪草品种 ,用田间试验方法对其适应能力和草坪品质进行了深入研究 ,结果证明 ,所有冷季型草坪草在沈阳、北京、兰州和昆明都能适应和生长 ;在过渡带 (成都和上海 )冷季型草越夏较难 ,冬季生长旺盛 ,而暖季型草都适应 ,但冬季枯黄期长 ;在广州除了高羊茅越夏能存活外 ,其余冷季型草坪草均不能越夏 ,只适于暖季型草如狗牙根等生长。 相似文献
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魏静 《四川畜牧兽医学院学报》2009,(4):28-32
在现代法律秩序中,商会自治规范是制定法的基础和必要的补充,甚至在某些方面替代了制定法;商会自治规范主要包括商会组织规范、行为规范、惩罚规范以及争端解决规范等;其效力仅及于其内部成员;商会自治规范和制定法之间存在冲突,但也存在整合的基础。 相似文献
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本文概述了猪的毛色类型、猪的毛色遗传模式,着重综述了猪毛色基因分子基础的研究进展,指出存在问题并就未来发展方向做了思考。 相似文献
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REASONS FOR PERFORMING STUDY: Centesis of the bicipital bursa using an 8.9 cm long spinal needle has been reported but the alternative of employing a 3.8 cm long hypodermic needle requires validation. OBJECTIVE: To compare the efficacy of 2 different methods of centesis of the bicipital bursa and to evaluate the usefulness of ultrasonographic imaging to determine the location of solution administered when centesis of the bursa is attempted. METHODS: For Trial 1, 6 clinicians, who had no previous experience of centesis of the bicipital bursa, attempted to inject a solution composed of an aqueous radiopaque contrast medium and physiological saline solution (PSS) into the bicipital bursae of 2/12 horses using the previously described distal approach to inject one bursa and a proximal approach to inject the contralateral bursa. The bicipital tendon and bursa were examined ultrasonographically before and after injection; and both shoulders were examined radiographically to identify the location of the medium. In Trial 2, another 6 clinicians, also with no previous experience of centesis, repeated Trial 1, using 6 horses, but the radiopaque contrast medium was mixed with air instead of PSS. RESULTS: Accuracy of centesis using the proximal approach was 39% and that of the distal approach 28%. Ultrasonographic examination of the shoulder allowed the location of solution and air to be accurately predicted in all 12 shoulders examined. CONCLUSIONS: Clinicians who have had no previous experience performing centesis of the bicipital bursa are unlikely to be successful in centesis using either approach. Radiographic examination after injecting a radiopaque contrast medium may be necessary to assess the success of centesis especially if bursal fluid is not obtained during centesis. Injecting air along with the radiopaque contrast medium provides more accurate ultrasonographic confirmation of centesis and better radiographic definition than does injection without air. 相似文献
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Effects of size of ingestively masticated fragments of plant tissues on kinetics of digestion of NDF
Ingestively masticated fragments were collected and sized via sieving. Different sizes of esophageal masticate and ruminal digesta fragments, and ground fragments of larger masticated pieces were incubated in vitro, and undigested NDF remaining at intervals of up to 168 h of incubation was determined. The ruminal age-dependent time delay (tau) for onset of digestion of NDF was positively correlated (P < 0.004) with the mean sieve aperture estimated to retain 50% of the fragments between successive sieve apertures (MRA). Degradation rate of potentially degradable NDF (PDF) and level of indigestible NDF were not related (P > 0.10) to MRA of masticated and ground fragments. Estimates of tau were positively related to MRA, with slopes of bermudagrass < corn silage < ruminal fragments of corn silage. It was concluded that fragment size-, and consequently, ruminal age-dependent onset of PDF degradation of a mixture of different fragment sizes results in an age-dependent rate of degradation of the more rapidly degrading of two subentities of PDF. Models are proposed that assume a tau before onset of simultaneous degradation of PDF from two pools characterized as having gamma-modeled age-dependency and age-constant rates. The ruminal age-dependent pool seems to be associated with the faster-degrading pool, and its rate parameter increases with range in MRA in the population of fragments. Conceptually, the ruminal age-dependent rate parameter for PDF degradation seems to represent a composite of several effects: 1) effects of the size-dependent tau; 2) range in MRA of the population of ingestively masticated fragments; and 3) subentities of PDF that degrade via more rapid age-dependent rates compared with subentities of PDF that degrade via age-constant rates. The estimated fractional rates of ruminative comminution of ingestively masticated fragments (0.060 to 0.075/h) were of a magnitude similar to the mean fractional rates of PDF digestion (0.030 to 0.085/h), which implies that ruminative comminution may be first-limiting to fractional rate of PDF digestion. The in vivo roles of ingestive and ruminative mastication of fragments on PDF degradation must be considered in any kinetic system for estimating PDF digestion in the rumen. These results and others in the literature suggest that the rate of surface area exposure rather than intrinsic chemical attributes of PDF may be first-limiting to degradation rate of PDF in vivo. 相似文献
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乳酸杆菌作为益生菌广泛用于人和动物.本文综述了乳酸杆菌改善宿主健康的机制.乳酸杆菌可通过产生抗菌物质如乳酸、过氧化氢、细菌素,或者通过竞争营养或肠道黏附位点来抑制致病菌;通过诱导黏附素的分泌或阻止细胞凋亡而增强肠道的屏障功能,从而保护肠道.文章重点讨论了乳酸杆菌表面成分(表面蛋白、脂磷壁酸和肽聚糖)与肠道受体(C型凝集素受体、Toll样受体和Nod样受体),阐述了他们结合后启动免疫调节信号,调控肠道免疫功能以发挥改善健康作用的机制. 相似文献
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Billinghurst RC Brama PA van Weeren PR Knowlton MS McIlwraith CW 《American journal of veterinary research》2004,65(2):143-150
OBJECTIVE: To determine whether serum concentrations of biomarkers of skeletal metabolism can, in conjunction with radiographic evaluation, indicate severity of osteochondrosis in developing horses. ANIMALS: 43 Dutch Warmblood foals with varying severity of osteochondrosis. PROCEDURE: 24 foals were monitored for 5 months and 19 foals were monitored for 11 months. Monthly radiographs of femoropatellar-femorotibial and tibio-tarsal joints were graded for osteochondral abnormalities. Serial blood samples were assayed for 8 cartilage and bone biomarkers. At the end of the monitoring period, foals were examined for macroscopic osteochondrosis lesions. RESULTS: Temporal relationships were evident between certain serum biomarkers and osteochondrosis severity in foals during their first year. Biomarkers of collagen degradation (collagenase-generated neoepitopes of type-II collagen fragments, type-I and -II collagen fragments [COL2-3/4C(short)], and cross-linked telopeptide fragments of type-I collagen) and bone mineralization (osteocalcin) were positive indicators of osteochondrosis severity at 5 months of age. In foals with lesions at 11 months of age, osteochondrosis severity correlated negatively with COL2-3/4C(short) and osteocalcin and positively with C-propeptide of type-II procollagen (CPII), a collagen synthesis marker. Radiographic grading of osteochondrosis lesions significantly correlated with macroscopic osteochondrosis severity score at both ages and was strongest when combined with osteocalcin at 5 months and CPII at 11 months. CONCLUSIONS AND CLINICAL RELEVANCE: The ability of serum biomarkers to indicate osteochondrosis severity appears to depend on stage of disease and is strengthened with radiography. In older foals with more permanent lesions, osteochondrosis severity is significantly related to biomarker concentrations of decreased bone formation and increased cartilage synthesis. 相似文献