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紫花苜蓿是优质的多年生豆科牧草,广泛种植于世界各地。豌豆蚜是紫花苜蓿的主要害虫之一,其不仅可危害植物生长,还会传播多种植物病害,从而降低牧草产量和品质,造成巨大的经济损失。丛枝菌根(AM)真菌可与80%的陆生植物根系共生形成互惠共生的菌根结构,其可促进植物对矿物营养的吸收,增强植株抗逆性。以紫花苜蓿为材料,探究AM真菌对植物应答豌豆蚜胁迫的生化机理。结果表明,AM真菌可以通过促进植物生长和养分吸收,改变植株防御性酶活性以及植物激素信号物质含量来调控植物自身对蚜虫的响应。2种AM真菌根内球囊霉和幼套球囊霉均显著提高了紫花苜蓿生物量、分枝数和植株N、P含量(P<0.05)。此外,根内球囊霉显著提高了植物过氧化物酶(POD)活性,且蚜虫处理下,较不接菌处理,根内球囊霉植株的POD、过氧化氢酶(CAT)活性以及激素信号物质水杨酸(SA)含量均显著增加(P<0.05)。在蚜虫处理下,相比不接菌处理,幼套球囊霉显著增强了植株POD活性(P<0.05)。蚜虫取食显著提高了植株SA含量,降低了超氧化物歧化酶(SOD)活性(P<0.05);且接种AM真菌后,蚜虫处理下的根系POD活性和SA含量提升程度更大,表明AM真菌可抑制蚜虫对植株造成的负效应。 相似文献
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《草业学报》2020,(1)
紫花苜蓿是优质的多年生豆科牧草,广泛种植于世界各地。豌豆蚜是紫花苜蓿的主要害虫之一,其不仅可危害植物生长,还会传播多种植物病害,从而降低牧草产量和品质,造成巨大的经济损失。丛枝菌根(AM)真菌可与80%的陆生植物根系共生形成互惠共生的菌根结构,其可促进植物对矿物营养的吸收,增强植株抗逆性。以紫花苜蓿为材料,探究AM真菌对植物应答豌豆蚜胁迫的生化机理。结果表明,AM真菌可以通过促进植物生长和养分吸收,改变植株防御性酶活性以及植物激素信号物质含量来调控植物自身对蚜虫的响应。2种AM真菌根内球囊霉和幼套球囊霉均显著提高了紫花苜蓿生物量、分枝数和植株N、P含量(P0.05)。此外,根内球囊霉显著提高了植物过氧化物酶(POD)活性,且蚜虫处理下,较不接菌处理,根内球囊霉植株的POD、过氧化氢酶(CAT)活性以及激素信号物质水杨酸(SA)含量均显著增加(P0.05)。在蚜虫处理下,相比不接菌处理,幼套球囊霉显著增强了植株POD活性(P0.05)。蚜虫取食显著提高了植株SA含量,降低了超氧化物歧化酶(SOD)活性(P0.05);且接种AM真菌后,蚜虫处理下的根系POD活性和SA含量提升程度更大,表明AM真菌可抑制蚜虫对植株造成的负效应。 相似文献
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为了研究苏打盐碱胁迫下紫花苜蓿的生理生化反应,试验采用不同浓度的Na2CO3和Na HCO3混合液对紫花苜蓿的幼苗进行盐碱胁迫,测定紫花苜蓿幼苗在受到不同浓度的苏打盐碱胁迫时各项生理生化指标,分析苏打盐碱胁迫对紫花苜蓿生理生化的响应机制。结果表明:苏打盐碱浓度为50~150 mmol/L时,紫花苜蓿叶片的甜菜碱、可溶性糖、脯氨酸含量三项生理指标和超氧化物歧化酶(SOD)、过氧化物酶(POD)两种抗氧化酶活性会随着苏打盐碱溶液浓度的增加而增加,在150 mmol/L时达到最大值;当胁迫浓度超过150 mmol/L时随着浓度的增加,紫花苜蓿叶片的甜菜碱、可溶性糖和脯氨酸含量及SOD、POD活性均下降。 相似文献
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以光叶紫花苕子为供体植物,采用生物测定法,研究供体材料地上部及地下部不同浓度浸提液(2.5、5.0、10.0、20.0、40.0 g·L-1)对燕麦、黑麦草、紫花苜蓿和白三叶4种牧草种子萌发过程的影响,以期为牧草间的轮作提供理论依据。结果表明:在供试浓度范围内,光叶紫花苕子地上部浸提液明显抑制紫花苜蓿和白三叶的种子萌发,且白三叶种子发芽率随着浓度的增加而降低,40 g·L-1处理下的白三叶种子发芽率与对照相比减少62.5%;光叶紫花苕子地下部浸提液抑制黑麦草、紫花苜蓿和白三叶幼苗根长,其中,40 g·L-1处理下紫花苜蓿根长与对照相比抑制作用最为显著,抑制率达64.94%;在地下部浸提液对4种牧草幼苗苗高的影响中,紫花苜蓿幼苗苗高在40 g·L-1处理下与对照相比差异显著。同时发现,不同浓度的浸提液处理均降低黑麦草、紫花苜蓿和白三叶幼苗叶绿素含量,而增加燕麦幼苗叶绿素含量,在20 g·L-1地下部浸提液处理下,燕麦叶绿素含量与对照相比增加144.23%;地下部浸提液均显著增加紫花苜蓿与白三叶幼苗过氧化物酶(POD)活性,与对照相比差异显著;浸提液处理可增加白三叶幼苗的过氧化氢酶(CAT)活性,但其降低紫花苜蓿幼苗的CAT活性。 相似文献
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以紫花苜蓿幼苗为材料,用聚乙二醇(PEG-6000)作为渗透介质人工模拟干旱条件,外源喷施NO供体硝普钠(SNP)、钙信号试剂CaCl2、NO抑制剂亚甲基蓝(MB)和Ca2+通道阻断剂LaCl3,对紫花苜蓿幼苗光合特征、抗氧化酶活性及过氧化物酶(POD)同工酶图谱进行研究,探讨了渗透胁迫下NO介导的Ca2+信号对紫花苜蓿幼苗光合作用及抗氧化能力的影响。结果表明:在渗透胁迫条件下,施加SNP、CaCl2均能够有效缓解叶片叶绿素a、类胡萝卜素及总叶绿素含量降低,提高叶片净光合速率(Pn)、气孔导度(Gs)及气孔限制值(Ls),而对胞间CO2浓度(Ci)没有缓解作用。SNP、CaCl2及SNP+CaCl2处理提高了幼苗叶片中抗氧化酶活性和脯氨酸含量,降低了丙二醛(MDA)含量。其中共处理时效果最为显著,第4天 SOD、POD、CAT活性较PEG处理升高了39.29%、30.41%和56.24%,脯氨酸含量增加了45.59%,MDA含量降低了45.59%。POD同工酶图谱在第4天时酶谱带数最多,POD活性最强,且SNP+CaCl2共处理下出现新酶带。而添加外源NO的同时添加Ca2+通道阻断剂LaCl3,紫花苜蓿幼苗光合速率、抗氧化酶活性及脯氨酸含量均降低,丙二醛含量增加,添加Ca2+信号的同时施加NO抑制剂MB也具有相同的作用,说明Ca2+信号参与NO信号转导过程并相互作用共同调节渗透胁迫下紫花苜蓿幼苗的生理应答响应。 相似文献
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本试验以紫花苜蓿种子为试验材料,添加外源一氧化氮供体硝普钠(SNP)、CaCl_2及抑制剂亚甲基蓝(methylene blue,MB)和LaCl_3,对种子进行浸种处理,以研究NO介导的Ca~(2+)信号在干旱胁迫下紫花苜蓿种子萌发及抗氧化酶中的传导作用。结果表明,15%PEG胁迫下紫花苜蓿种子萌发受到明显抑制,当外源添加NO或Ca~(2+)处理后萌发指标均有上升,外施0.1mmol/L SNP或10mmol/L CaCl_2都能有效缓解PEG对紫花苜蓿种子的胁迫伤害。干旱胁迫下NO+Ca~(2+)共处理时效果最为显著,萌发率较SNP处理提高了8.96%,较CaCl_2处理提高了19.67%。共处理时比SNP、CaCl_2处理时提高了种子淀粉酶活性、淀粉含量、可溶性糖、可溶性蛋白及脯氨酸含量,降低了MDA含量和超氧阴离子产生速率,显著提高了SOD,POD,CAT活性。其中淀粉酶活性、淀粉含量、可溶性蛋白、可溶性糖、脯氨酸含量以及POD活性的变化中,均表现出:NO和Ca~(2+)共处理下各指标变化要慢于单一处理。当添加外源NO的同时添加Ca~(2+)通道抑制剂La~(3+),NO的促进效果受到抑制,而添加外源Ca~(2+)的同时添加NO抑制剂亚甲基蓝,Ca~(2+)的促进效果受到抑制,表明NO经由Ca~(2+)信号通路调控干旱胁迫下紫花苜蓿的信号传导。 相似文献
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为探究外源甜菜碱对镉(Cd)胁迫下紫花苜蓿幼苗生长的影响,设置叶施和根施两种不同施加方式以及6个外源甜菜碱(glycine betaine,GB)浓度(0、10、20、30、40、50 mmol/L),在镉(25 mg/L)胁迫下测定‘甘农3号’紫花苜蓿种子萌发以及相关抗逆生理指标。结果表明,与单独胁迫对照相比,施加适宜浓度的外源GB均能提高镉胁迫下紫花苜蓿种子的发芽率、发芽势、发芽指数以及活力指数,其中30 mmol/L的GB对Cd胁迫下抑制种子萌发的缓解作用最佳;叶施和根施30 mmol/L GB,对紫花苜蓿的叶绿素、根长、株高增加值、根部含水量均有显著提高;叶施30 mmol/L和根施50 mmol/L GB显著提高紫花苜蓿幼苗叶片中游离脯氨酸(Pro)含量、抗氧化酶(SOD、POD、CAT)活性,抑制丙二醛(MDA)含量的升高;通过隶属函数分析可知,叶施和根施30 mmol/L的外源GB对缓解苜蓿幼苗Cd胁迫的效果最佳。 相似文献
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PEG模拟干旱胁迫下硅对紫花苜蓿萌发及生理特性的影响 总被引：1，自引：0，他引：1
在已知硅能提高植物抗逆性的基础上,采用实验室发芽法研究PEG干旱模拟下,硅对紫花苜蓿(Medicago satiava L.‘Sadie7’)萌发及生理的影响。初步探讨硅肥对紫花苜蓿抗旱性的调控机制,以期筛选出有效提高紫花苜蓿抗旱性的适宜硅肥浓度。结果表明:在一定干旱程度和适宜硅浓度下,紫花苜蓿种子发芽率、发芽势和胚根长有所提高,过氧化物酶(POD)、超氧化物歧化酶(SOD)和过氧化氢酶(CAT)活性增加,而丙二醛(MDA)含量降低。在10%PEG胁迫下,施用1.00mmol·L~(-1)硅酸钾显著提高紫花苜蓿种子发芽势和发芽率,当硅酸钾浓度达到2.50mmol·L~(-1)时会抑制其发芽。在10%和15%PEG浓度下,1.00 mmol·L~(-1)硅酸钾处理后胚根长显著(P0.05)大于对照。在5%和10%PEG胁迫下,2.00mmol·L~(-1)硅酸钾处理显著提高了紫花苜蓿幼苗超氧化物歧化酶(SOD)活性;在15%PEG浓度下,2.50mmol·L~(-1)硅酸钾处理显著降低了幼苗丙二醛(MDA)含量,且提高过氧化物酶(POD)活性和过氧化氢酶(CAT)活性。干旱胁迫程度不同,所适宜的能提高紫花苜蓿抗旱性的硅酸钾浓度不同。研究表明,硅从紫花苜蓿种子萌发开始就作用其生理生化过程,并且提高其抗逆性。 相似文献
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为探究放牧方式对青藏高原高寒草地家畜的采食量和植物补偿生长的影响,本试验在环青海湖流域高寒草地设置放牧方式（牦牛单独放牧、藏羊单独放牧、牦牛和藏羊1：2混牧、牦牛和藏羊1：4混牧、牦牛和藏羊1：6混牧）控制试验,以期确定草地的承载力,并为制定合理的草地管理措施提供依据。试验结果表明：在群落水平上,家畜的采食量在藏羊（Ovis aries）单独放牧以及牦牛（Bos grunniens）与藏羊1：2混牧方式下,显著高于其他方式（P<0.05）;在功能群水平上,藏羊单独放牧与牦牛和藏羊1：2混牧这2种放牧方式下家畜对豆科植物的采食量较高;藏羊单独放牧与牦牛和藏羊1：2混牧植物的补偿生长能力显著高于其他放牧方式（P<0.05）。研究表明：藏羊单独放牧时,其采食量最高;牦牛和藏羊1：2混牧的放牧方式对植物补偿性生长的促进作用最明显。因此,从放牧家畜采食量与植物补偿生长两方面考虑,在青藏高原高寒草地藏羊单独放牧与牦牛和藏羊1：2混牧的放牧方式较为合理。 相似文献
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《Strength and Conditioning Journal》2007,60(1):71-78
Studies of Anderson and Scherzinger's forage conditioning hypothesis have generated varied results. Our objectives were: 1) to evaluate late summer/early fall forage quality of crested wheatgrass (Agropyron desertorum [Fisch. ex Link] J. A. Schultes), bluebunch wheatgrass (Pseudoroegneria spicata [Pursh] A. Löve), Idaho fescue (Festuca idahoensis Elmer), bottlebrush squirreltail (Elymus elymoides [Raf.] Swezey), Thurber's needlegrass (Achnatherum thurberianum [Piper] Barkworth), and basin wildrye (Leymus cinereus [Scribn. & Merr.] A. Löve) from ungrazed paddocks and paddocks grazed at vegetative, boot, and anthesis; and 2) test hypotheses that postgrazing regrowth yields were correlated with soil moisture content when grazing occurred. Crop–year precipitation for 1997 and 1998 was 134% and 205% of average. Crude protein (CP) and in vitro dry matter digestibility (IVDMD) of ungrazed grasses displayed expected declines in quality. Among ungrazed grasses, late summer/early fall CP was 5.7% in 1997 and 3.6% in 1998; IVDMD was 47% and 41%, respectively. Late summer/early fall forage quality was elevated by vegetative, boot stage, or anthesis grazing. The phenologically youngest regrowth always ranked highest in CP and IVDMD. Among grasses, respective 1997 CP and IVDMD means were 9.0% and 55% for regrowth following anthesis grazing. No regrowth followed anthesis grazing in 1998, but CP and IVDMD means from boot stage treatments were 5.5% and 47%, respectively. With CP measures, a species by treatment interaction occurred in 1997, but species reacted similarly in 1998. Vegetative, boot stage, and anthesis grazing in 1997 caused respective late summer/early fall standing crop reductions of 34%, 42%, and 58%; and 34%, 54%, and 100% reductions in 1998. Forage conditioning responses were lower for bluebunch wheatgrass and crested wheatgrass than other grasses. Soil moisture content was a poor predictor of regrowth yields. Managed cattle grazing can successfully enhance late season forage quality. 相似文献
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Spectral analysis was used to relate dietary quality and herbage species to the behavior of grazing steers. Four .3-ha paddocks were established with either 'AU-Triumph' tall fescue (F; Festuca arundinacea Schreb.), 'Apollo' alfalfa (A; Medicago sativa L.), 1/3 fescue and 2/3 alfalfa (2/3A), or 2/3 fescue and 1/3 alfalfa (1/3A). Each paddock was stocked with 10 to 16 steers and defoliated in 5 d. Three steers on each paddock carried vibracorders to monitor grazing time. Daily forage samples were taken in 10-cm layers and weighed. Esophageal extrusa were collected from fistulated steers to measure diet quality. Daily grazing time did not differ (P = .37) among treatments; however, steers grazing mixtures grazed numerically longer (1.4 h/d) than steers on monocultures. Spectral analysis revealed that steers grazing A and 2/3A had many daily meals of short duration, but steers grazing 1/3A and F consumed three meals daily at 8-h intervals. Throughout the 4.67-d grazing period, quality of the diet linearly declined in crude protein and herbage digestibility, linearly increased in neutral detergent fiber and cellulose, and exhibited quadratic changes in lignin and ash. For most quality values, the tall fescue monoculture differed from the others (P < .05). Steers selected diets with similar quality for the A, 2/3A, and 1/3A treatments. This study illustrates how differences in forage diets alter grazing behavior of steers. 相似文献
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为探究划区轮牧对放牧型紫花苜蓿(Medicago sativa L.)人工草地产量与品质的影响,本研究开展周期为36 d的6个小区划区轮牧试验,通过对在牧期和牧后再生期紫花苜蓿地上生物量与粗蛋白、粗脂肪、粗灰分、中性洗涤纤维、酸性洗涤纤维指标含量的测定,研究在牧期和牧后再生期紫花苜蓿产量与品质的变化规律,以期为轮牧制度的合理制定提供依据。结果表明：7—8月进行划区轮牧时,在牧期紫花苜蓿的产量和品质均随放牧时间的延长而降低,根据地上生物量和粗蛋白含量的降低量计算出苜蓿草地平均每天为每只羊提供的干物质和粗蛋白量分别为1.65 kg和318 g。牧后再生期紫花苜蓿的产量随时间的延长而升高,品质则随时间的延长先升高后降低,在21 d时品质最好,经过30 d的再生,地上生物量可达3.73 t·hm-2,粗蛋白产量可达0.8 t·hm-2。另外,由于绵羊采食的选择性,导致仅剩木质化茎秆的残茬对再生初期苜蓿品质的影响较大,建议牧后对残茬进行刈割以提升再生期草品质。 相似文献
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喀斯特山区草地施肥对放牧乌蒙半细毛羊抗氧化系统功能的影响 总被引：1，自引：0，他引：1
为选择草地施肥的肥料种类,减少施肥对乌蒙半细毛羊产业的影响,在威宁县凉水沟种羊场多年生人工草地开展施肥和放牧试验。 结果表明:凉水沟种羊场人工草地牧草铜含量相对较低,但仍高于乌蒙半细毛羊营养需要标准;施肥极显著增加牧草氮含量(P<0.01),各施肥处理之间没有明显差异。硫酸铵施肥显著增加牧草硫和锌含量(P<0.01),显著降低了牧草硒的含量(P<0.01)。放牧试验结束时,施硫酸铵草地的乌蒙半细毛羊血液中铜、铁和硒的含量极显著低于施硝酸铵草地和对照组(P<0.01), 动物血液锌和硫含量极显著高于硝酸铵施肥牧场和对照组(P<0.01)。硫酸铵施肥牧场的乌蒙半细毛羊血红蛋白、红细胞压积容量极显著低于硝酸铵施肥牧场和对照牧场(P<0.01),血清铜蓝蛋白含量、血清超氧化物歧化酶活力、血清谷胱甘肽过氧化物酶活力和血清过氧化氢酶等抗氧化酶的活力极显著低于硝酸铵施肥牧场和对照牧场(P<0.01),丙二醛的含量显著高于硝酸铵施肥牧场和对照牧场(P<0.01)。血液其他矿质元素和血液指标及血清生化值在2个施肥处理和对照之间均差异不显著。 因此得出结论,草地施肥的种类需要根据土壤矿物质分布和含量情况确定,铜含量低的牧场不适合硫酸铵施肥,硫酸铵施肥明显影响了乌蒙半细毛羊机体抗氧化系统功能。 相似文献
17.
牧草如何生长--植物生长与放牧管理之关联 总被引：2，自引：1，他引：1
RonaldESosebee DavidBWester JCarlosVillalobos CarltonMBritton ChangguiWan HishamNofal 《草业学报》2005,14(1):117-125
适当管理饲料饲草资源的基本原则是理解多年生牧草如何生长.长期以来,对根系生长有了基本的了解,对去叶和环境对根系生长的影响也知之甚多.然而,对去叶、干旱及其他环境因素对多年生牧草的影响以及这些牧草对去叶的反应缺乏应有的理解.从牧草返青到开花,植物处于短枝阶段,适度放牧并不对多年生牧草的健康和活力造成危害,因为植物会弥补其失去的叶片.然而,当牧草从短枝向长枝阶段(节间伸长和开花期)转移时,碳水化合物主要用于节间伸长和开花过程.在开花后和休眠前期,碳水化合物主要向茎基和植物基部转移,以供来年新枝条的发育.因此,在花后和休眠前期,放牧系统必须被调节到"无放牧"状态."无放牧"状态,如休息、轮牧、延迟轮牧和快速轮牧制,其价值在于这种定期的禁牧可提高多年生牧草的活力,改善草地的健康状况,并且在不利的环境条件下,保证在植物去叶后的后续生产能力. 相似文献
18.
《Strength and Conditioning Journal》2020,73(1):53-60
Knowledge of herbivory tolerance of dominant plant species and their responses to varying grazing intensity is required for sustainable grazing management in semiarid rangeland ecosystems. In a field experiment, we studied the effects of simulated grazing 0%, 30%, 50%, and 80% leaf removal (control, partial, intermediate, and heavy leaf removal) of three dominant perennial legumes: Astragalus cyclophyllon, Astragalus effuses, and Hedysarum criniferum in semiarid rangelands of southwestern Iran for 2 yr and tested 1) differential herbivory tolerance in terms of regrowth ability of belowground and aboveground biomass (AGB), fecundity, and nonstructural carbohydrate reserves; and 2) trade-off between forage quantity and quality—less defoliated plants produce larger amount of biomass with less forage quality and vice versa. The results showed a reduction in AGB and reproduction in each of the three plants. However, three forbs exhibited some sort of variations in shoot and root growth, reproduction and forage quality under intermediate and heavy leaf removal. Leaf removal in individuals of A. effusus and H. criniferum are more likely to compensate for tissue loss by allocating the available resources to the expansion of root biomass, at the cost of AGB and reproductive effort. Leaf removal also led to an increase in forage quality in each of the three forb species, depending on the level of height removal. The control plant had a higher amount of biomass production and lower amount of crude protein compared with heavy leaf removal treatments (i.e., 80%), by contrasting responses of acid detergent fiber and neutral detergent fiber, indicating a trade-off between forage quality and forage quantity. The results indicate that there is a balance among forage quantity, quality, and regrowth ability of belowground and aboveground tissues in intermediate leaf removal treatments of these forb species. This balance is used to develop principles for grazing management of steppe rangelands because such a regime meets different criteria including forage quantity, quality, and nonstructural carbohydrate reserves. 相似文献
19.
Our objective was to determine the short-term response of bluebunch wheatgrass and medusahead to defoliation of wheatgrass designed to stimulate regrowth through tillering. We hypothesized that defoliating bluebunch wheatgrass by 20% at the 3 to 3.5 leaf stage followed by a 50% defoliation at peak standing crop would increase its tillering and biomass production. Consequently, we expected a reduction of the density and biomass of medusahead over that of bluebunch wheatgrass defoliated 50% at peak standing crop. Treatments included four initial medusahead densities (200, 333, 444, 600 plants · m-2) created by hand-pulling and three defoliation regimes factorially arranged (12 treatment combinations) in a randomized complete-block design and replicated four times at two sites. In 2006 and 2007, defoliation was accomplished by hand-clipping bluebunch wheatgrass 1) by 50% once at peak standing crop (late June); 2) by 20% at the 3 to 3.5 leaf stage, then again to 50% at peak standing crop (mid May, late June); or 3) plants were not clipped. Density was sampled in 2006 and 2007, and biomass was harvested only at Star Mountain (near Riverside, Oregon) in 2007 because Warm Springs (near Drewsey, Oregon) was burned by a wildfire before final 2007 data could be collected. In 2006, no treatments applied at either site detectably altered the number of tillers produced by bluebunch wheatgrass nor did they affect bluebunch wheatgrass density or biomass in 2007 at Star Mountain. Changes in medusahead density were not detected in 2006, but this annual invasive grass increased in density and biomass in 2007 at Star Mountain in plots receiving two defoliations. The relatively short growing period caused by summer drought and the relative intolerance of bluebunch wheatgrass to grazing make the twice-over grazing an unlikely practice for arid rangelands in the western United States. In fact, it could possibly increase the risk of annual grass invasion. 相似文献
20.
D. L. Barnes 《African Journal of Range and Forage Science》2013,30(1):138-145
Although an adequate knowledge of growth patterns and defoliation effects in perennial grasses is a prerequisite for the rational use of veld and pastures for animal production, our knowledge of this subject is far from adequate. The results of various physiological and clipping studies on tropical and subtropical grasses are appraised and their weaknesses in providing information applicable in practical management are indicated. It is suggested that there is a need for increased emphasis on studies of growth patterns and defoliation effects giving priority to (a) defining and evaluating the extrinsic and intrinsic factors affecting differential response to similar defoliation treatments in different circumstances, (b) applying defoliation treatments with a practical bias, and (c) determining actual defoliation patterns under grazing. 相似文献