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对热研10号、热研2号和有钩柱花草的种子进行不同浸种时间和不同浓度赤霉素(GA3)处理,从中筛选出适合的浸种时间和GA3浓度。结果表明,浸种24h时3种柱花草种子发芽率均最高,分别由10%,84%和24%提高到18%,86%和36%。经200mg/kg GA3处理的热研2号和有钩柱花草种子的发芽率、发芽指数、发芽势和活力指数最高,100mg/kg GA3处理的热研10号种子的发芽率、发芽指数、发芽势和活力指数最高,所以低浓度(100、200mg/kg)GA3处理有利于促进3种柱花草种子的萌发,但幼苗长度与GA3浓度之间未表现出明显的规律,500mg/kg GA3处理的热研10号和热研2号幼苗长度最长。 相似文献
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赤霉素和生长素浸种对野牛草种子萌发及幼苗生长生理的影响 总被引：1，自引：0，他引：1
为研究外源激素对野牛草(Buchloe dactyloides)种子破除休眠和幼苗生长生理的作用,本研究分别设置3个浓度的赤霉素(GA3)和生长素(IAA)对野牛草进行浸种处理,浸种后进行发芽试验,对浸种后种子的萌发及幼苗生长情况、非结构性碳水化合物和内源激素进行测定。结果表明,1)赤霉素浸种可以有效增强野牛草种子发芽力,提高发芽势、发芽率、发芽指数和种子活力指数,其中,2 000mg·L-1的赤霉素处理效果最显著(P0.05);适当浓度的生长素浸种可以有效增强野牛草种子的生活力。2)赤霉素处理有助于野牛草幼苗地上部的生长;生长素处理对野牛草幼苗地下部和根冠比有显著(P0.05)的增强作用,其中较低浓度(250mg·L-1)处理效果最明显。3)1 500mg·L-1赤霉素与450mg·L-1生长素浸种均可显著(P0.05)提高野牛草幼苗可溶性糖与淀粉的积累。4)较高浓度的外源赤霉素和生长素浸种处理会使野牛草幼苗内源生长素、赤霉素、脱落酸(ABA)含量上升,其中,2 000 mg·L-1的赤霉素和450mg·L-1的生长素浸种效果最佳。综上所述,打破野牛草种子休眠、促进地上部生长及其幼苗内源赤霉素含量的最佳试剂和浓度为2 000 mg·L-1的赤霉素,增加可溶性糖和淀粉在野牛草幼苗期积累的最佳试剂和浓度是1 500mg·L-1的赤霉素;促进野牛草幼苗地下部生长的最佳试剂和浓度是250mg·L-1的生长素,增加野牛草幼苗内源生长素和脱落酸含量的最佳试剂和浓度是450mg·L-1的生长素。 相似文献
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以杂花苜蓿阿尔冈金(Medicago varia cv.ALgonquin)为试验材料,采用沙培方法,研究了外源一氧化氮(NO)供体硝普钠(SNP)对Pb2+处理下杂花苜蓿种子萌发及幼苗生理特性的影响。结果表明,与对照比,用SNP(100μmol/L)、低Pb2+浓度(250mg/L)和SNP与低Pb2+浓度组合(100μmol/L SNP+250mg/L)处理均增加了杂花苜蓿种子的发芽势、发芽率、胚芽胚根长,提高了幼苗脯氨酸、可溶性糖及可溶性蛋白质的含量,增强了根系活力,降低了MDA含量。高Pb2+浓度(500mg/L)处理不利于杂花苜蓿种子萌发和幼苗生长,且100μmol/L SNP不能缓解高铅胁迫对种子萌发及幼苗生长的抑制作用。 相似文献
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种子休眠程度深、发芽率低是限制虉草栽培利用的重要因子.通过对3个年份采收的虉草种子发芽试验、吸水率测定及种子萌发抑制物活性的生物鉴定,揭示虉草种子休眠机理;并利用植物激素、硝酸钾和有机溶剂浸泡处理虉草种子,以探寻打破虉草种子休眠的最佳方法.结果表明:虉草种子休眠属于种皮吸水障碍、存在萌发抑制物和胚生理休眠的综合性休眠,其中萌发抑制物是限制种子萌发的首要因素.用100mg/L GA3、100mg/L 6BA、150mg/L KT或4g/L KNO3浸泡虉草种子24h可显著提高其发芽势、发芽率和发芽指数,其中以4g/L KNO3浸种24h效果最好,平均发芽率可提高到91 ％,比对照高137％;其次是100mg/L GA3浸种24h,平均发芽率为84％,比对照高118％. 相似文献
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促进偃麦草属植物种子萌发是偃麦草属植物栽培草地成功建植的关键。通过不同浓度外源赤霉素 GA3溶液(0、500、1 000、1 500 和 2 000 mg/L)对长穗偃麦草、中间偃麦草和偃麦草种子进行浸种处理,分析外源 GA3对 3 种偃麦草属植物种子萌发及生理特性的影响。结果表明：随外源 GA3处理浓度的增加,3 种偃麦草属植物种子发芽率和发芽势均显著提高,1 500 mg/L 是最适合打破种子休眠而萌发的浓度;GA3浸种处理促进了 3 种偃麦草属植物种子胚根和胚芽的生长,提高了内源生长促进物质 IAA 和 GA3 含量,降低生长抑制物质 ABA 含量,且提高了胚芽的 POD 活性,降低了 MDA 含量。 1 500 mg/L 外源 GA3浸种处理可较好地调控种子内源激素含量继而促进种子萌发,为偃麦草属植物种子高效生产和草地建植提供了理论依据。 相似文献
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为筛选出促进盐碱胁迫下紫苏种子萌发和幼苗生长的最佳外源物质及其处理浓度,本试验以紫苏种子为材料,研究不同浓度的氯化钙(CaCl2)、褪黑素(Melatonin, MT)、赤霉素(Gibberellin, GA)浸种24 h对盐碱胁迫下紫苏种子萌发和幼苗生长的影响。结果表明：3种外源物质浸种处理均能够有效缓解紫苏受到的盐碱胁迫,促进种子萌发、幼苗生长,提高抗氧化酶活性。CaCl2,MT,GA缓解盐碱胁迫的最佳浓度分别为10 mmol·L-1,100μmol·L-1,50 mg·L-1,其中,50 mg·L-1GA对促进种子萌发效果最佳,100μmol·L-1MT对促进幼苗胚根伸长和抗氧化酶SOD,CAT,POD活性升高效果最佳,而促进幼苗胚芽伸长和鲜重增加的最佳处理为300 mg·L-1GA。利用隶属函数综合评价得出,50 mg·L-1GA浸种24 h是盐碱胁迫下促进紫苏种子萌发和幼苗生长的最... 相似文献
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《北方蚕业》2019,(4):8-13
利用硫氢化钠溶液浸种处理,探讨外源施加硫化氢能否缓解重金属镉、砷对桑树种子萌发及幼苗生长的胁迫作用。结果表明:镉和砷胁迫对桑树种子的发芽率、发芽势、发芽指数、种苗生长量、种子活力指数均有显著抑制作用,对胚根伸长的抑制尤为严重,且抑制作用随浓度升高而增强;与重金属胁迫处理组相比,0.3 mmol/L、0.9 mmol/L、1.5 mmol/L硫氢化钠浸种处理能够显著提高镉或砷胁迫下桑树种子的发芽率、发芽势、发芽指数、种苗生长量以及种子活力指数,且提高的程度随着处理浓度的升高而加强,1.5 mmol/L硫氢化钠浸种处理的效果最好,但硫氢化钠浸种处理并不能显著改善重金属镉或砷胁迫对于胚根伸长的抑制作用。 相似文献
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以老化饲用燕麦种子为对象,探讨外源褪黑素对NaCl胁迫下老化燕麦种子萌发和幼苗相关形态和生理特性的影响。结果表明:在无胁迫时添加褪黑素可以提高老化燕麦种子的发芽率,并能增加幼苗游离脯氨酸和可溶性蛋白质含量且增强过氧化物酶活性,降低丙二醛含量;不同浓度的外源褪黑素(100μmol/L、300μmol/L、500μmol/L、800μmol/L、1000μmol/L)处理均能显著提高NaCl(浓度150mmol/L)胁迫下老化燕麦种子的发芽率、苗高、根长、苗鲜重、过氧化物酶活性、可溶性蛋白质和游离脯氨酸含量,显著降低幼苗根冠比和丙二醛含量(P<0.05)。加权隶属函数分析表明,提高老化燕麦种子NaCl胁迫下活力的最佳褪黑素浓度为500μmol/L,此时相对于NaCl胁迫,种子发芽率、苗鲜重、过氧化物酶活性和可溶性蛋白质含量分别提高了245.61%、325.55%、52.28%、121.27%。 相似文献
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模拟干旱胁迫下镁对高羊茅种子萌发的影响 总被引：1，自引：0，他引：1
采用PEG-6000(100,200,300g/L)模拟水分胁迫,研究不同浓度的硫酸镁溶液(0.2,0.4,0.6,0.8g/L)浸种对高羊茅(Festuca arundinacea)种子萌发的影响。结果表明:随着干旱胁迫程度的增加,高羊茅的发芽率,发芽指数,苗长,根长,幼苗鲜重及根鲜重等指标均呈下降趋势。在种子萌发阶段,轻度干旱胁迫(PEG=100g/L)下,硫酸镁浸种对高羊茅种子的萌发促进作用不明显,其发芽率、发芽势、发芽指数与对照差异不显著;中度干旱胁迫(PEG=200g/L)下,0.6g/L的镁使得高羊茅种子的萌发相对最佳,其发芽等指标与对照差异显著(P0.05);重度干旱胁迫下(PEG=300g/L),0.4g/L镁处理明显的促进了高羊茅种子的萌发,其发芽指标与对照差异显著(P0.05),而当镁浓度是0.8g/L时,则抑制了高羊茅种子的萌发。在幼苗的生长前期,轻度干旱和中度干旱胁迫下,0.6g/L镁处理对高羊茅的苗长、根长、幼苗鲜重及根鲜重等生长指标有显著的促进作用;重度干旱胁迫下,0.4g/L和0.6g/L的镁处理使其生长指标高于对照且差异显著(P0.05)。 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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以国际标准强毒Ｒ株人工感染非免疫产蛋鸡,定时扑杀,分别从鼻窦、眶下孔、气管、肺、气囊、卵巢和输卵管分离ＭＧ,并收集感染鸡所产蛋分离ＭＧ。结果表明,人工感染４８小时后上、下呼吸道及肺已被全面感染,９６小时气囊已被感染,１２０小时输卵管已能分离到ＭＧ,卵巢始终分离不到ＭＧ。人工感染鸡自１４４小时便能在其所产蛋中分离出ＭＧ。药物治疗能在７２小时内消除感染,油乳剂苗则需２４天后逐渐降低蛋内ＭＧ分离率,药物卵内注射、种蛋药浴、高温处理均能杀死卵内ＭＧ,但以研制的种蛋浸泡剂药浴效果为最好。 相似文献