Effects of Nitrogen Fertilization on Some Turfgrass Characteristics of Perennial Ryegrass (Lolium perenne L.)

The paper aimed to study the effects of nitrogen fertilization on the yield and some plant characteristics of perennial ryegrass (Lolium perenne L.). The study was conducted at Agricultural Research and Application Center of the Faculty of Agriculture in Igdir University in 2013. In the experiment, eight levels of fertilizers: 0, 10.0, 20.0, 30.0, 40.0, 50.0, 60.0 and 70.0 kg N/ha per month were applied in perennial ryegrass (Lolium perenne L.) during the sixth growing season. A randomized complete block with three replications was used as the experimental design. Nitrogen application affected plant height, green grass yield, plant covering rate, canopy color and turfgrass quality values of perennial ryegrass positively. In both monthly and as the average of nitrogen application, times of application (spring, summer and fall) caused the most uniform turfgrass quality and establishment. Results indicated that although a significant impact was on the character investigated, such as the leaf length, green grass yield, plant cover ratio, canopy color and turfgrass quality, the doses of nitrogen fertilizer have created close to each other in groups. In the stand point of view of all characters, N1, N2 and N3 were located in first group, N4 and N5 in the second group, N6 and N7 in the third group, expect for control (N0). It can be concluded that 40.0-50.0 kg N/ha per month may be more suitable to be used in ryegrass production in the landscape.

Italian Ryegrass (Lolium perenne ssp. multiflorum) and Corn (Zea mays) Competition

Italian ryegrass is an annual/biennial grass that is typically used as a pasture crop or a cover crop along roadsides, rights-of-way, and industrial areas. Glyphosate-resistant (GR) Italian ryegrass populations have been documented around the world, mostly in orchard and vineyard situations. The first evidence of evolved GR Italian ryegrass in row/agronomic crops was reported from Washington County, Mississippi in 2005. GR Italian ryegrass populations can jeopardize preplant burndown options in reduced-tillage crop production systems, thereby, delaying planting operations. The effects of competition of Italian ryegrass on crop growth and yield are poorly understood. A field study was conducted in the 2012 growing season and repeated in the 2013 growing season. GR and susceptible (GS) Italian ryegrass populations were established in the greenhouse and transplanted in prepared corn row beds in the fall of 2011 and 2012 at 0, 1, 2, 3, and 4 plants·meter> of crop row. Italian ryegrass plants overwintered and developed over the following spring-summer. Glyphosate was applied at 1.26 kg·ae/ha (1.5× of labeled rate) in the spring to burndown the Italian ryegrass plants and corn was planted into the ryegrass residue 2 - 3 wk later. Current corn production practices were followed. Corn density (early and late season), height (early season), and yield and Italian ryegrass biomass (early-mid season) measurements were recorded during both years. Corn height was greater in 2012 than that in 2013 at comparable stages of the growing season, due to a cooler and wetter early season in 2013 than that in 2012. Averaged across weed densities, corn density (both early and late season) and yield were higher in the GS than those in the GR population, but Italian ryegrass biomass was similar for both populations. Averaged across Italian ryegrass populations, corn density (both early and late season), and yield were inversely proportional to Italian ryegrass density. In summary, Italian ryegrass significantly reduced corn density and yield and reduction was greater with the GR than that with the GS population. Studies are underway to study inter population competition in Italian ryegrass and investigate allelopathic effects of Italian ryegrass on selected crops.

Cu^2＋胁迫对黑麦草(Lolium perenne L.)去除富营养化水体中氮、磷效果的影响

为探讨不同浓度Cu2+胁迫对黑麦草去除富营养化水体中N、P营养盐效果的影响,采用小试培养的方法,研究了Cu2+存在条件下黑麦草对水体中N、P去除的动力学过程及黑麦草植株对不同浓度Cu2+胁迫的生态响应.结果表明,0.1~2.0 mg/LCu2+胁迫均降低了黑麦草对水中N、P营养盐的去除速率,其去除过程符合二阶动力学模型.黑麦草对水体中Cu2+亦有良好的去除作用,根部是积累重金属Cu的主要部位,其对Cu2+的吸收速率符合米氏动力学方程.较低浓度Cu2+(≤0.2 mg/L)胁迫对黑麦草去除N、P的效果影响不大,并且能促进黑麦草生物量的增加,而较高浓度Cu2+(≥0.5 mg/L)胁迫虽有促进根系数量增加的趋势,但明显抑制了黑麦草根伸长和叶片生长等作用,因而严重影响了黑麦草对水体中N、P的去除.

黑麦草种子及幼苗对镉胁迫的生理响应

为了探明不同黑麦草品种对镉(Cd)富集能力的差异及其生理机制,以6个黑麦草品种为材料,研究镉胁迫对其种子萌发、生物量、镉吸收、色素含量、光合特性及抗逆特性的影响。结果表明,与正常生长条件相比,镉胁迫对不同黑麦草品种种子萌发和根芽生长具有低促高抑作用。镉胁迫增加了黑麦草光合色素含量;镉胁迫增加了维纳斯、奔驰、维多利亚叶片的气孔导度、胞间CO_(2)浓度、蒸腾速率;镉胁迫增加了奔驰、维多利亚、蓝标叶片的POD活性;镉胁迫增加了卡特、维多利亚叶片的SOD活性;镉胁迫增加了维多利亚、维纳斯叶片的CAT活性。奔驰、维多利亚、维纳斯可能较其他品种具有更强的耐镉性,从而减少镉对自身的危害;镉胁迫增加了所有品种可溶性糖含量及除卡特外的5个黑麦草品种脯氨酸含量,奔驰、蓝标、维多利亚能产生较多的渗透调节物质来减轻镉胁迫对其造成的伤害;在正常生长条件下,黑麦草地上部镉含量和镉累积量都较低,品种间差异较小。镉胁迫明显增加了黑麦草地上部镉含量和镉累积量,奔驰地上部镉含量和镉累积量最高,显著高于其他品种。综上,奔驰、维多利亚抗镉性及富镉能力较强,是镉污染土壤修复的优选品种。

Study on the Degradation Trend of Ryegrass-White Clover Artificial Grassland

[Objective] The study aimed to explore the degradation law and trend of artificial grassland. [Method] Taking the ryegrass （Lolium perenne） - white clover （ Trifolium repens） artificial grassland in Maiping Township, Guizhou Province as the research object, the grassland vegetation of 40 quadrate from different areas （area around the sheep shed, hilltop, hillside, flatland at the foot of the hill） were analyzed by comparing the dominance and richness index. [ Result] Degradation of different degrees appeared in various areas of this artificial grassland. To be specific, the degradation of grassland around the sheep shed was not serious for less consumption by the sheep; however, the areas on the hilltop and hillside degenerated to the grassland types of dallis grass （ Paspalum dilatatum Poir. ） -Indian lovegrass （ Eragrostis pilosa） and dallis grass - cogongrass [ Imperata cylindrica （ Linn. ） Beauv. ], respectively, and the area at the foot of the hill degenerated to the grassland type dominated by garland chrysanthetnum （ Chrysanthemum coronarium L. ） and knotgrass （ Paspalum distichum L. ）. [ Conclusion ] This study provided a basis for grassland improvement as well as the efficient and sustainable utilization of grazing-type artificial grassland in South China.

Revegetation of Copper Mine Tailings with Ryegrass and Willow

To restore vegetation on metal mine tailings is very difficult because theyoften contain high concentrations of heavy metals, low nutrient content and low water retentioncapacity. This study involved 3 experiments that evaluated the effects of 4 treatment amendments:montmorillonite, rice straw, organic manure and chemical fertilizer on the growth of ryegrass(Lolium perenne L.) and willow (Salix viminalis L.) with Cu and Zn mine tailings from two miningareas. The results showed that ryegrass was the most tolerant of 4 crops to Cu toxicity. Also whenorganic manure, which contained high concentrations of inorganic salts, was added to the minetailings, it significantly hindered ryegrass growth (P = 0.05). Meanwhile, with ryegrass organicmanure significantly increased (P = 0.05) the extractable Cu concentration in both mine tailings.When montmorillonite was used as a mine tailings amendment with willow, the height and tress numberat the 1st cut were significantly greater (P = 0.05) than a control without montmorillonite. Howeverthere was no significant difference for height, tress number, dry weight or root dry weight at the2nd cut. So, amendment applications to reduce metal toxicity and increase nutrients retention inmine tailings were essential during revegetation of mine tailings.

过量表达拟南芥HD-START转录因子AtHDG11提高黑麦草(Lolium perenne)抗旱性的初步研究

本研究通过农杆菌介导法,获得了5个PCR和Southern杂交检测阳性的AtHDG11转基因黑麦草株系。相比野生型再生植株,转基因植株具有更发达的根系,同时在干旱胁迫下具有较低的MDA含量,并且具有较高水平的超氧化物歧化酶(superoxide dismutase,SOD)和过氧化氢酶(catalase,CAT)活性。这些结果均显示过量表达AtHDG11能够提高黑麦草的耐旱性。

添加糖蜜对青稞秸秆和多年生黑麦草混合青贮发酵品质及营养价值的影响

试验在青稞秸秆与多年生黑麦草以6∶4混合的基础上,添加3%,4%和5%的糖蜜,旨在进一步改善混合青贮发酵品质和营养价值,为西藏地区青稞秸秆青贮利用提供理论依据。结果显示,青贮前14天,糖蜜添加组乳酸含量快速增加,pH值迅速下降。对照组pH值未能降至4.2以下,而糖蜜添加组均在4.0左右,乳酸、水溶性碳水化合物含量和乳酸/乙酸显著高于(P<0.05)对照组,氨态氮/总氮均低于对照组,且添加3%糖蜜已达到优质青贮饲料标准。青贮第60天糖蜜添加组有较高的粗蛋白含量,较低的中性洗涤纤维和酸性洗涤纤维含量,各组体外降解率均高于青贮材料。综合考虑,在青稞秸秆和黑麦草以6∶4混合的基础上添加3%的糖蜜可获得优质青贮饲料。

铅梯度胁迫对多年生黑麦草幼苗生理生化特性影响

本试验以盆栽黑麦草幼苗为材料,研究了不同的胁迫时间(7,14,21,28d),不同的铅浓度(500,1 000,1 500mg/L)对黑麦草的抗氧化酶(SOD、POD)、细胞膜(MDA、相对电导率)及渗透调节物质(SS、Pro)的影响。结果表明,随着铅浓度的增加,黑麦草叶片中的SOD活性变化整体为先上升后下降,在低浓度(500和1 000mg/L)和短时间(7和14d)胁迫下SOD活性明显升高,之后快速降低。POD活性随着胁迫时间及铅浓度增加呈显著的下降趋势,在28d时,1 500mg/L浓度下,POD活性最低,为45.9U/g。随着胁迫时间及铅浓度的增加,MDA含量及相对电导率整体呈上升趋势,且MDA含量与铅浓度呈线性正相关(r2>0.96)。可溶性糖(SS)含量变化复杂,在较高浓度及较长时间作用下趋于减少。脯氨酸(Pro)含量在较低铅浓度胁迫下会明显增加,但浓度过高超过黑麦草忍耐极限,就会有所下降。表明黑麦草在重金属铅胁迫中经历了一个忍耐和逐渐受损的过程。

Zn胁迫对黑麦草幼苗生长、生理生化及Zn吸收的影响

采用营养液培养法,研究了不同Zn浓度(0,0.25,0.50,1.00,2.00 mm o l/L)对黑麦草幼苗生长、过氧化物酶活性、脯氨酸、根系活力及Zn吸收的影响。结果表明,低锌胁迫对黑麦草幼苗生长无抑制,过度锌胁迫(Zn≥2 mm o l/L)将降低黑麦草地上部干质量。幼苗叶内游离脯氨酸含量随锌胁迫时间、锌浓度增加而增加。随Zn胁迫时间增加幼苗POD活性先降后升、根系活力先升后降,锌处理的植株地上部POD活性随锌浓度增加先降低,然后增加,而根系活力随锌浓度增加而增加。黑麦草幼苗地上部和根系Zn含量随Zn浓度的增加而增加,当Zn浓度为2.00 mm o l/L时,地上部Zn含量最大值为775.0 m g/kg。

苏打碱胁迫对多年生黑麦草的生理影响

为研究苏打碱胁迫对多年生黑麦草幼苗的生长和生理特性的影响,采用水培实验,用0.1mol/L的Na2CO3和NaHCO3溶液配置pH=8.2、pH=9.1、pH=9.9、pH=10.9四个梯度的处理液,以去离子水pH=6.5作为对照,探讨pH值对黑麦草蒸腾速率、株高、根长、含水量、叶绿素含量、丙二醛(MDA)含量以及抗氧化酶系统中超氧化物歧化酶(SOD)、过氧化氢酶(CAT)、过氧化物酶(POD)活性的影响。结果表明,随着pH的升高,幼苗的株高、根长、含水量、相对蒸腾速率及叶绿素含量都显著下降,而根冠比呈先升后降的趋势。随着处理液的pH值从8.2递增至10.9,叶片中的MDA含量从对照的7.0nmol/g FW逐步上升到30.0nmol/g FW;而SOD活性先高后低,当pH=9.1时,最高含量为8.4U/mg蛋白;CAT的活性则从对照的118.5U/(min.g蛋白)逐步递减至47.1U/(min.g蛋白);而POD活性呈现递增的趋势,当pH达到最高时,POD活性是对照的4倍多。

渭北黄土高原旱地果园生草对土壤物理性质的影响

【目的】研究旱地果园生草土壤物理性状的变化特征。【方法】在黄土高原旱地苹果园生草区及清耕区设立标准地,在60cm土层内分层取样,测定土壤容重、孔隙度、水稳性团聚体的含量等土壤物理性状,分析果园生草土壤物理性质的变化特征。【结果】生草降低土壤容重,增加孔隙度,提高水稳性团聚体含量,其影响主要集中在0～40cm土层;生草种类不同,对果园土壤物理性状影响存在差异,种植白三叶效果更佳;随着生草年限的增加,果园土壤物理性状愈趋改善,土壤的入渗性能和持水能力得到较大幅度的提高。【结论】长期生草有利于果园土壤物理性状的持续改善。

海藻糖合酶基因转化黑麦草及耐旱性研究

以多年生黑麦草(Lolium perenne L.)种子成熟胚为外植体,在MS附加5mg/L2,4-D、500mg/L的L-脯氨酸、130mg/L天门冬酰氨、10mg/LAgNO3的诱导培养基(MSJ)上诱导胚性愈伤组织。用基因枪法将ubiqutin启动子驱动的海藻糖合酶基因(TPS基因)转入多年生黑麦草的胚性愈伤。在含有5mg/LBialaphos的选择培养基上经过2个月的抗性筛选,抗性愈伤组织在分化培养基上生成了898株再生植株,其中的220株检测为阳性株,检测的阳性率占供检株数的24.5%。PCR分析及PCR-Southern杂交鉴定表明,TPS基因已整合到黑麦草的基因组中。抗旱性鉴定表明,转基因黑麦草在干旱胁迫条件下的保水能力增强,电解质渗出率明显低于对照,耐旱性提高。

黑麦草对NaHCO_3胁迫的光合生理响应

为了探讨牧草对碱胁迫的光合生理响应,采用营养液砂培方法,研究了不同浓度NaHCO3(0,50,100,150,200mmol/L)胁迫对黑麦草幼苗叶片光合色素含量、气体交换参数、叶绿素荧光和叶黄素循环的影响。结果表明,1)随着NaHCO3浓度增大,叶绿素和类胡萝卜素含量逐渐降低,叶绿素a/b不断提高,净光合速率(Pn)、气孔导度(Gs)、蒸腾速率(Tr)和气孔限制值(Ls)下降,胞间CO2浓度(Ci)升高,表明非气孔限制是碱胁迫下Pn降低的主要因素。2)PSⅡ初始荧光(Fo)随NaHCO3浓度提高明显上升,最大荧光(Fm)、最大光化学效率(Fv/Fm)、实际光化学效率(ΦPSⅡ)和光化学猝灭(qP)显著下降,非光化学猝灭(NPQ)呈增加趋势。3)随着NaHCO3浓度提高,天线转化效率(Fv′/Fm′)降低,激发能在2个光系统间的分配不平衡性(β/α-1)增大,叶片吸收的光能中用于光反应的比例(P)下降,而天线热耗散的比例(D)增加,叶黄素循环脱环氧化状态(A+Z)/(V+A+Z)呈先升后降趋势,表明依赖叶黄素循环的天线热耗散是碱胁迫下黑麦草耗散过剩光能的主要途径。

多年生黑麦草高频再生体系的建立及优化

从外植体预处理方式、基本培养基、激素浓度等方面着手,对多年生黑麦草愈伤组织诱导、继代、不定芽分化及再生过程中的影响因素进行了研究,提高了再生频率。结果如下：切取胚端半粒种子,经75%乙醇处理1min,0.1%HgCl处理15min,在经无菌水清洗4～6次后接种方式较好;愈伤组织诱导培养基以MS＋2,4—D 8.0 mg/L（或另添加甘露醇25 g/L）为佳;愈伤组织接种于MS＋2,4—D 8.0mg/L＋甘露醇25 g/L上进行1～2次继代后于NB＋6—BA2.0 mg/L上进行分化;不定芽转接至MS＋6—BA2.0 mg/L上进行扩繁或于1/2MS＋NAA0.5mg/L＋IAA0.5mg/L上进行生根。

草坪型多年生黑麦草主要生长发育特性的研究

1997～ 1999年在宁夏引黄灌区研究了草坪型多年生黑麦草主要生长发育特性。结果表明 ,草坪型多年生黑麦草 5～ 9月各月出叶速度与月平均温度的关系可用一元二次方程来表示 :Y =9 4 986 +0 0 6 2 4t -0 0 10 4t2 (R =0 9987 ) ;主茎的叶序与分蘖之间存在数量上的同伸关系“三 0 ,四 1,五 2 ,六 4 ,七 7,八12”。花后 2 6～ 2 7d ,小穗干重最大 ,其含水量为 4 1 15 % ,种子不易落粒 ,为多年生黑麦草种子适宜收获期。

植物油脂包膜尿素的氮素释放及其对黑麦草养分吸收利用的影响

以环境友好的植物油脂为包膜材料制得2种包膜尿素,连续溶出试验以商品包膜尿素(CCU)为对照,测定POU1、POU2的氮素释放状况,盆栽试验设不施肥处理(CK)、不施氮处理(PK)、普通尿素处理(NU)、商品包膜尿素处理(CCU)、自制包膜尿素处理(POU1、POU2),研究新型包膜尿素对多年生黑麦草养分吸收及氮素利用状况的影响。溶出试验结果表明,POU1、POU2的氮素累积溶出量显著低于CCU(P<0.05),且POU2显著低于POU1(P<0.05);在等氮处理条件下,施用POU2处理的黑麦草地上部含氮量明显高于NU处理,甚至达到显著水平(P<0.05),3次刈割后,POU1、POU2处理的黑麦草地上部总干物量和氮、磷、钾总积累量显著高于NU处理(P<0.05)。另外,POU1、POU2处理的黑麦草氮肥表观利用率明显高于NU处理(P<0.05)或CCU处理。植物油脂包膜尿素,尤其是POU2,能改善黑麦草氮素营养状况,增加黑麦草地上部氮、磷、钾的吸收,促进黑麦草生长。说明植物油脂可以作为包膜材料,植物油脂包膜尿素可视为新型缓释尿素。

缺磷对黑麦草-内生真菌共生体生长和根中酚含量的影响

培养液中缺磷或内生真菌感染对黑麦草地上部生长的影响不显著 ,但二者的交互作用却有着显著影响。随着磷浓度的下降 ,感染内生真菌的黑麦草显示出较强的生长优势 。

利用流式细胞术鉴定黑麦草倍性方法的研究

为了测定几种不同倍性的黑麦草核DNA含量,利用流式细胞术(Flow Cytometry,FCM)检测黑麦草的染色体倍性,并通过传统的染色体制片的方法对其结果进行验证。结果表明不同品种间细胞核DNA含量差异显著,且随着倍性水平的增加,细胞核DNA相对含量随之成倍增加。流式细胞术检测结果与染色体制片检测结果一致。利用流式细胞仪测定黑麦草核DNA含量,具有样品制备简单,测量快速,精度高等优点,是进行倍性鉴定的理想方法。

多年生黑麦草成熟胚再生体系的建立及基因枪转化

目的 :建立以多年生黑麦草成熟胚为起始材料的再生体系 ,用于基因枪转化。方法 :多年生黑麦草成熟种子在附加 5mg L 2 ,4 D的MS培养基上诱导愈伤组织 ,转至新继代培养基上产生胚性愈伤组织。分化培养基为无激素MS培养基。再生植株在培养基成分减半的无激素MS培养基生根 ,之后移栽至土壤。基于这一再生体系 ,用含有水稻几丁质酶基因RC2 4的质粒pARN6和含有草丁膦乙酰转移酶基因Bar的质粒pDB1 ,通过基因枪轰击胚性愈伤组织。用附加PPT的继代培养基进行转化植株的抗性筛选。结果 :共获得 2 4 3株再生植株。通过PCR进行检测 ,获得1 8株整合有RC2 4基因的植株 ,1 5株整合有Bar基因的植株 ,同时转入 2个基因的植株 2株。