3种禾本科牧草抗旱性的初步鉴定

以当前贵州主栽品种努依黑麦草为对照，利用生物学鉴定方法对贵州省草业研究所选育的黔草1号、2号苇状羊茅的抗旱性加以初步鉴定。结果表明：在干旱逆境条件下，随着土壤的干涸，引起3种牧草失水，导致蛋白质合成减弱和分解增强，致使其含量下降，且叶绿素的形成受到抑制，含量迅速减少，甚至耗尽。3种牧草的抗旱性强弱顺序为：黔草1号〉黔草2号〉努依黑麦草。     

3种禾本科牧草抗旱性的初步鉴定

以当前贵州主栽品种努依黑麦草为对照,利用生物学鉴定方法对贵州省草业研究所选育的黔草1号、2号苇状羊茅的抗旱性加以初步鉴定。结果表明:在干旱逆境条件下,随着土壤的干涸,引起3种牧草失水,导致蛋白质合成减弱和分解增强,致使其含量下降,且叶绿素的形成受到抑制,含量迅速减少,甚至耗尽。3种牧草的抗旱性强弱顺序为:黔草1号>黔草2号>努依黑麦草。     

Na2CO3胁迫对牧草苗期生长的影响

测定了Na2CO3胁迫下五种禾本科牧草苗期的植株存活率、生物量、生长胁迫指数等生长指标与其耐盐性的关系.结果表明五种牧草的存活率(浓度＞0.5%)、鲜重与干重均随着Na2CO3胁迫浓度的升高而降低,草种间耐盐性差异显著,其耐盐性强弱顺序是野大麦＞披碱草＞肥披碱草＞老芒麦＞无芒雀麦.     

Na_2CO_3胁迫对牧草苗期生长的影响

测定了Na2CO3胁迫下五种禾本科牧草苗期的植株存活率、生物量、生长胁迫指数等生长指标与其耐盐性的关系。结果表明:五种牧草的存活率(浓度>0.5%)、鲜重与干重均随着Na2CO3胁迫浓度的升高而降低,草种间耐盐性差异显著,其耐盐性强弱顺序是野大麦>披碱草>肥披碱草>老芒麦>无芒雀麦。     

植物生长延缓剂和修剪对多年生黑麦草抗旱性的影响

对植物生长延缓剂和修剪处理下多年生黑麦草的抗旱性进行研究.结果表明在干旱胁迫的各个阶段,留茬6 cm处理叶片含水量和游离脯氨酸含量显著高于其他处理.各延缓剂处理下的叶片含水量和游离脯氨酸含量均高于对照,可显著增强多年生黑麦草的抗旱性.     

植物生长延缓剂和修剪对多年生黑麦草抗旱性的影响

对植物生长延缓剂和修剪处理下多年生黑麦草的抗旱性进行研究。结果表明:在干旱胁迫的各个阶段,留茬6cm处理叶片含水量和游离脯氨酸含量显著高于其他处理。各延缓剂处理下的叶片含水量和游离脯氨酸含量均高于对照,可显著增强多年生黑麦草的抗旱性。     

干旱胁迫对香根草生长及光合生理主要特征的影响

对干旱、半水淹和对照(正常灌水)等三种处理香根草在30 d后的生长状况,以及退水、复水40 d后三种处理香根草对光合有效辐射(PAR)增强的光合生理主要特征进行研究.结果表明复水、退水后,干旱、半水淹处理香根草Pn、Tr和WUE均已恢复正常,说明香根草具有相当强的抗旱耐涝能力.     

干旱胁迫对香根草生长及光合生理主要特征的影响

对干旱、半水淹和对照(正常灌水)等三种处理香根草在30d后的生长状况,以及退水、复水40d后三种处理香根草对光合有效辐射(PAR)增强的光合生理主要特征进行研究。结果表明:复水、退水后,干旱、半水淹处理香根草Pn、Tr和WUE均已恢复正常,说明香根草具有相当强的抗旱耐涝能力。     

西部大开发造就牧草种子大市场

生态建设是实施西部大开发战略的重要内容，作为生态建设和治理国土的基本材料－牧草种子的重要性日渐突出，草地生态建设，沙尘暴治理，退耦还林（草）和大面积的草原建设，水土流失治理等工程都迫切需要大量适应性强，能防沙治沙的优质牧草种子，巨大的需求必将刺激牧草种子业的大发展。     

甘肃野生草地早熟禾萌发期抗旱性鉴定与评价

采用-0.1,-0.3,-0.5和-0.7 MPa的聚乙二醇6000（PEG-6000）模拟不同程度的干旱胁迫,在萌发期分别处理8份野生草地早熟禾（Poa pratensis）种质和2个商用品种21 d,并测定发芽率、发芽势和活力指数等7个鉴定指标,并以其相对值作为评价指标,利用隶属函数法和聚类分析对供试的10份种质材料进行了综合评价和分类,同时,对各鉴定指标在草地早熟禾萌发期抗旱性评价中的作用进行了比较分析。结果表明,用于草地早熟禾萌发期抗旱性研究的适宜PEG-6000浓度为-0.1～-0.3 MPa,种子活力指数和发芽率受干旱胁迫的影响较大,且与抗旱性的关系最为密切,可作为草地早熟禾种质萌发期抗旱性鉴定的重要指标。10份种质材料抗旱性由强到弱依次为：秦州 > 西和 > 陇西 > 安定 > 渭源 > 天祝 > 榆中 > MidnightⅡ > 清水 > Baron;聚类分析可把供试材料按抗旱性强弱分为三类,其中清水和Baron属于干旱敏感种质;安定、渭源和MidnightⅡ等属于中等抗旱种质;秦州、西和和陇西属于抗旱种质,可作为抗旱育种材料。     

Opuntia Forage Production Systems: Status and Prospects for Rangeland Application

This paper reports recent findings in Opuntia genetics, nutrient fertilization, and cultivation with promise to overcome limitations for Opuntia-based forage production systems. The essentially spineless, fast-growing Opuntia ficus-indica (L.) Mill. has been planted on millions of hectares for forage in tropical areas of Brazil and North Africa. The spiny, cold-hardy Opuntia species have been used for forage in Mexico and the southwestern United States, after the cladodes have been chopped or singed to remove the spines. Due to the recent increases in fuel prices, burning of the spines is more costly. Where only spiny varieties exist, some range animals forage on them without manipulation. As a result, spines frequently penetrate and form lesions on mouth and esophageal tissues, leading to serious health issues. Slow growth and low protein (ca. 5%) of the native Opuntia spiny species on nonfertilized rangeland is an impediment to greater use of Opuntia for forage. The only spineless species adaptable to US Department of Agriculture cold hardiness zones < 8 (i.e., Opuntia ellisiana Griffiths) is relatively slow growing. Full sibling crosses indicate spine heritability is probably single-gene controlled. Interspecific hybrids between the frost-sensitive, fast-growing, and spineless O. ficus-indica with cold-hardy, spiny, slower-growing O. lindheimerii Engelm. have produced spineless progeny, with greater cold hardiness than O. ficus-indica, and greater productivity than cold-hardy, spineless O. ellisiana. Nitrogen limitations on water-use efficiency of Opuntia have been overcome for the 120 million ha of semiarid northeastern Brazil with added nitrogen and phosphorus fertilization. With control of competing vegetation and fertilization, this system has 40 t dry matter · ha^-1 of 9.2% crude protein forage with 600 mm rainfall in 16 mo. Opuntia ficus-indica plantations were profitable even though a duplication of fertilizer current prices was considered.     

The Effect of Herbicide Application During the Winter on Forage Production,Animal Performance,and Grain Yield of Winter Wheat

Winter wheat (Triticum aestivum L.) is used for both forage and grain production throughout the U.S. Southern Great Plains region. Management practices to increase grain yield may affect winter forage production and as a result, animal performance. The objective of this study was to determine the effect of applying herbicides in the winter to control broad leaf weeds on winter and spring forage production, animal performance, and subsequent grain yield. Four 8-ha wheat pastures at each of two locations were established under no-till practices each fall, then randomly assigned within location to receive one of the following four treatments: 1) no winter herbicides, 2) chlorsulfuron, 3) chlorsulfuron plus metsulfuron, or 4) triasulfuron. Herbicides were applied in December (yr 1) or January (yr 2) combined with 2,4-dichlorophenoxyacetic acid (2,4-D). Stocker steers were used as grazers to determine animal performance during winter (December to March) and spring (March to May) grazing periods. Animal performance and beef production per ha were not (P>0.10) affected by the application of herbicides. Animal productivity was related to climatic conditions, which affected both the energy required by the animal for maintenance and the amount of forage produced. Winter and spring forage production was not affected (P>0.10) by herbicide application. The amount of nonwheat biomass present at grain harvest was lower (P<0.03), the harvest index was higher (P<0.01), and the number of seed head was higher (P<0.01) for herbicide-treated plots than for control plots. Among the herbicides used, triasulfuron increased the number of seed heads and grain yield. Applying herbicides to winter wheat in the winter to control broadleaf weeds did not affect forage or animal production but did increase harvest index.     

铜、镉、铅对7种豆科牧草种子萌发和幼苗生长的影响

以蒸馏水为对照,研究了重金属铜、镉、铅离子对7种豆科植物种子萌发和幼苗生长的影响。结果表明,随着Cu²⁺,Cd²⁺和Pb²⁺浓度的增大,毛苕子(Vicia villosa)、红三叶(Trifolium pratense)、苜蓿(Medicago varia)、小冠花(Coronilla varia)、扁蓿豆(Medicago ruthenica)和百脉根(Lotus corniculatus)种子的发芽率、发芽指数、幼苗的根长和芽长均呈不同程度的降低趋势;但毛苕子的降低趋势相对较缓。经300 mg·L^-1的Cu²⁺处理后,红豆草种子发芽率显著高于对照(P <0.05),在200,300和400 mg·L^-1浓度的Cu²⁺下红豆草种子的发芽指数均显著高于对照;经150 mg·L^-1的Cd²⁺浓度处理下红豆草种子的发芽指数显著高于对照;在500和1000 mg·L^-1 的Pb²⁺处理下红豆草种子的发芽指数显著高于对照和2000 mg·L^-1 的Pb²⁺处理(P <0.05)。随着Cu²⁺,Cd²⁺和Pb²⁺离子浓度的增大,红豆草种子萌发后形成的幼苗的根长和芽长都呈降低趋势。采用模糊数学隶属函数法,对供试7种豆科植物种子相对发芽率、相对发芽指数、相对芽长和相对根长进行隶属函数值计算,得出种子萌发期耐重金属胁迫的隶属函数总平均值,耐Cu²⁺的强弱顺序为:红豆草 >毛苕子 >红三叶 >百脉根 >苜蓿 >扁蓿豆 >小冠花;耐Cd²⁺的强弱顺序为:红豆草 >毛苕子 >红三叶 >百脉根 >扁蓿豆 >苜蓿 >小冠花;耐Pb²⁺的强弱顺序为:红豆草 >毛苕子 >扁蓿豆 >红三叶 >小冠花 >苜蓿 >百脉根。综合分析,红豆草和毛苕子种子在萌发期对重金属Cu²⁺,Cd²⁺和Pb²⁺的耐性较好。     

甘肃省紫花苜蓿地方类型抗旱性的综合评判

对甘肃省紫花苜蓿地方类型的２１个抗旱性指标进行了测定,运用隶属函数法对１４个苜蓿品种的抗旱性进行了综合评判。根据综合评判值的大小,确定甘肃省紫花苜蓿地方类型的抗旱性强弱顺序为：民勤苜蓿、环县苜蓿、会宁苜蓿、榆中苜蓿、甘谷苜蓿、定西苜蓿、通渭苜蓿、镇原苜蓿、秦安苜蓿、临洮苜蓿、庆阳苜蓿、宁县苜蓿、礼县苜蓿、天水苜蓿。     

高温和干旱对白三叶生长发育及生理特性的影响

在夏季温室内分别对白三盆栽苗进行高温和土壤干旱处理，测定其植株生长发育和生理特性变化，以受胁迫伤害程度。研究认为，在保证土壤水分供应的情况下，白三叶能日均气温３６．２℃，极端最高气温４７．５℃的高温下正常生长发育，高温条件下土壤干旱会对白三叶生长发育造成逆境胁迫。随土壤干旱胁迫的增强，白三叶分枝生长量和分枝数的增加均受到不同程度的抑制，其中二级分枝的生长对土壤干旱较一级分枝的反应更敏感，叶片细胞膜     

四种紫花苜蓿在山东半干旱地区苗期生长的研究

就中牧一号、无棣苜蓿、阿尔冈金及金皇后4种紫花苜蓿在山东半干旱区的苗期生长进行了研究.结果表明,两种国产苜蓿(中牧一号及无棣苜蓿)出苗率较高,而进口苜蓿(阿尔冈金及金皇后)苗期生长较好.