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.

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.

Study on Sterilization Method of Endophytic Fungi in Tall Fescue(Festuca arundinacea)and Ryegrass(Lolium perenne)Seeds

[Objectives]This study was conducted to obtain the best solution for sterilizing tall fescue(Festuca arundinacea)and ryegrass(Lolium perenne)seeds by heating in a water bath for a short time.[Methods]The tall fescue and ryegrass seeds infected with endophytic fungi were sterilized by heating in a water bath to compare seed germination and initial growth of turfgrass seedlings under different treatment time.[Results]Sterilization in a 60℃water bath for 20 and 30 min both inhibited the germination of tall fescue and ryegrass seeds,while the 20 min treatment did not significantly affect the lengths of stems,leaves and roots of seedlings.The 20 min water bath sterilization treatment had no effects on the plant heights and biomass of the two turfgrass seedlings and the tiller number of ryegrass,but sterilization for 30 min significantly reduced the aboveground and total biomass of seedlings and the tiller number of ryegrass.[Conclusions]Sterilization in a water bath at 60℃ for 20 min achieved rapid sterilization in a short time,without significantly negatively affecting the growth of seedlings.

黑麦草(Lolium perenne L.)内生真菌的检测、分离及鉴定

从多年生黑麦草(LoliumperenneL.)5个品种———SR4000、Pinnacle、Topgun、CalypsoⅡ、Justus中分离出61个菌株。次培养后,所得形态稳定的菌株可分为4个形态群,依据其形态特征及APPCR的结果,确定其中的57个分离菌株为Neotyphodiumlolii。

黑麦草(Lolium perenne)根际细菌多样性对Ni污染沉积物修复效果的响应

应用黑麦草(Lolium perenne)对某滨海城市南排污河的重金属污染沉积物——底泥进行植物修复,并结合变性梯度凝胶电泳(DGGE)分析了黑麦草根际土壤的重金属Ni含量和细菌多样性的关系。结果表明,黑麦草对Ni的修复效果较好,种植黑麦草后根际土壤Ni浓度降低了11.8%。根际土壤中Ni有效态含量与根际土壤pH值的变化呈较好的正相关关系,相关系数为0.9688。对根际土壤细菌多样性进行分析,重金属Ni含量变化能够影响土壤细菌的多样性,根际土壤细菌多样性随黑麦草的生长而不断演变,且与根际土壤中Ni浓度变化有密切联系。对DGGE电泳后回收的部分片段进行测序并建立了进化树,结果表明,测序片段与非培养方法得到的菌种的同源性较高,且其均在土壤或河道底泥的相关研究中被发现。不同时期细菌群体组成和Shan non指数随着修复时间而变化,并与细菌总数有正相关关系。

普通小麦-黑麦草(Lolium perenne L.)易位系鉴定及其后代灌浆与产量性状分析

为明确外源染色体或片段对小麦籽粒灌浆和产量性状的影响,以普通小麦宁春4号和黑麦草远缘杂交后代为材料,借助分子细胞学手段鉴定其BC1代染色体组成,并对其BC1F3代籽粒灌浆和产量性状进行了分析。结果表明,ND99株系出现两个顶端小片段易位类型的GISH杂交信号,为真杂种;ND99的BC1F3后代中分离出有芒(ND99A)和无芒(ND99B)两种类型,并且同一个分子标记3EST-185能够追踪这两种类型。宁春4号和易位系后代(ND99A、ND99B)籽粒的体积、鲜重、干重、水分均表现为先增后降的变化趋势;宁春4号和ND99A的灌浆速率呈双峰曲线变化,而ND99B呈多峰曲线变化。宁春4号的灌浆时间早,快速增长期长,籽粒饱满指数和粒重最大;ND99A灌浆迟,持续期短,籽粒饱满指数最低,粒重仅次于宁春4号;ND99B灌浆的峰值出现较早、较大,灌浆持续期短,籽粒饱满指数居中,粒重最低。易位系后代的穗长、穗粒数和结实小穗数明显高于宁春4号,可能是影响其灌浆的关键因素之一。

热锻炼对高羊茅(Festuca arundinacea)和多年生黑麦草(Lolium perenne)抗高温能力的影响

夏季高温胁迫已成为限制冷季型草坪草生长和发育的一个主要问题。以两种耐热性不同的冷季型草坪草高羊茅和多年生黑麦草(前者较耐热)为材料,经过3d 30℃的热锻炼预处理后,分别在38、42、46℃的高温下处理14h。在这些高温条件下,研究了经过热锻炼预处理的高羊茅和多年生黑麦草叶片膜脂过氧化、抗氧化剂含量以及叶绿体超微结构的变化。结果表明:(1)热锻炼提高了高羊茅和多年生黑麦草的耐热性,显著缓减了高温条件下两种草坪草叶片膜脂过氧化程度的加剧,降低了叶片过氧化氢(H2O2)和超氧阴离子(O2.-)的产生速率。(2)高温条件下,热锻炼使高羊茅和多年生黑麦草叶片中抗氧化剂抗坏血酸(AsA)和谷胱甘肽(GSH)的含量下降程度有所缓减。(3)热锻炼减轻了高温胁迫对高羊茅和多年生黑麦草叶片叶绿体超微结构的损伤。这些结果说明热锻炼能够减轻高温对草坪草叶绿体的伤害可能与其在高温胁迫下和对照相比具有较高的抗氧化剂含量有关,这也可能是冷季型草坪草对高温的适应机制之一。

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.

Evaluation of a cost effective technique for treating aquaculture water discharge using Lolium perenne Lam as a biofilter

Wastewater stabilization ponds generate low cost by-products that are useful for agriculture. The utilization of these by-products for soil amendment and as a source of nutrients for plants requires a high level of sanitation and stabilization of the organic matter, to maintain acceptable levels of soil, water and air quality. In this study, two aquaculture wastewater treatment systems; recirculating system and a floating plant bed system were designed to improve the quality of irrigation water in local communities with low income. In both systems the grass species Lolium perenne Lam was used as a plant biofilter while vegetable specie Amaranthus viridis was used to evaluate the performance of the system and the suitability of the phyto-treated water for irrigation. It was found that the harmful material removal rate for recirculating system was 88.9% for TAN （total ammonia nitrogen）, 90% for NO2--N, 64.8% for NO3--N while for floating plant bed system 82.7% for TAN, 82% for NO2--N and 60.5% for NO3--N. Comparative analysis of the efficiency of waste element removal between the two systems revealed that both systems performed well, however, plant growth was not robust for floating plant bed system while recirculating system is energy consuming. Although both systems did not attain sufficient levels of TN （total nitrogen） and TP （total phosphorus） load reduction, the treatment with L. perenne remarkably improved the irrigation water quality. A. viridis plants irrigated with the phyto-treated discharge water had lesser concentrations of heavy metals in their tissues compared to those irrigated with untreated discharge. The control plants irrigated with untreated discharge were also found to be highly lignified with few stems and small leaves.

Phytoremediation of Heavy Metal Pollution in Urban Sewage River Sediment by Lolium perenne

[Objective] The aim was to restore heavy metal pollution of urban sewage river sediment by using Lolium perenne.[Method] Through cultivation test,the phytoremediation of heavy metal pollution in river sediment by L.perenne was analyzed from the aspects of removal effect,optimal removal time and the changes of sucrase activity,urease activity and microbe quantity.[Result] After planting L.perenne for three months,Ni content in sediment was basically stable,while the removal effect of Cr and Mn in sediment was optimal,and the removal rate of Cr reached the maximum value (57.1%).After 4-5 months,sucrase and urease activity were 4.59 and 10.34 times the previous activity respectively.In addition,the quantity of bacteria and fungi was 2-3 times the previous quantity after 3-4 months.In a word,L.perenne had obvious effects on the removing of heavy metal,improvement of enzyme activity and microbe quantity in polluted river sediment,and the optimal planting time of L.perenne was four months.[Conclusion] The study could provide theoretical foundations for the control of polluted sediment in river.

Transfer DREB into Lolium perenne L. to improve its drought tolerance

A method of Agrobacterium tumefaciens mediated transformation for perennial ryegrass was developed using the calli of ryegrass derived from mature enrbryos. The calli were inoculated with a disarmed A. tumefaciens strain EHA105 harboring binary vector p2328. Vector p2328 contained transcription factor DREB1B and neomycin phosphotransferase （npt H） genes which were driven by promoters of rd29B and CaMV35S, respectively. The inoculated calli were selected on paromomycin- or kanamycin-containing media till the established plants being transferred to soil. Six tmnsgenic plants with DREB1B had been obtained from perennial ryegrass strain Tove. PCR and Southern-blotting showed that npt Ⅱ and DREBIB genes were integrated in perennial ryegrass genome. Stress treatment confirmed that transgenic plants with higher drought tolerance were obtained.

Heterologous expression of Lolium perenne antifreeze protein confers chilling tolerance in tomato

Antifreeze proteins（AFP） are produced by certain plants, animals, fungi and bacteria that enable them to survive upon extremely low temperature. Perennial rye grass, Lolium perenne, was reported to possess AFP which protects them from cold environments. In the present investigation, we isolated AFP gene from L. perenne and expressed it in tomato plants to elucidate its role upon chilling stress. The T1 transgenic tomato lines were selected and subjected to molecular, biochemical and physiological analyses. Stable integration and transcription of Lp AFP in transgenic tomato plants was confirmed by Southern blot hybridization and RT-PCR, respectively. Physiological analyses under chilling conditions showed that the chilling stress induced physiological damage in wild type（WT） plants, while the transgenic plants remained healthy. Total sugar content increased gradually in both WT and transgenic plants throughout the chilling treatment. Interestingly, transgenic plants exhibited remarkable alterations in terms of relative water content（RWC） and electrolyte leakage index（ELI） than those of WT. RWC increased significantly by 3-fold and the electrolyte leakage was reduced by 2.6-fold in transgenic plants comparing with WT. Overall, this report proved that Lp AFP gene confers chilling tolerance in transgenic tomato plants and it could be a potential candidate to extrapolate the chilling tolerance on other chilling-sensitive food crops.

Aquaculture Solids Management Using A Combination of Sand/Gravel or Unwoven Fabric Bed With Lolium perenne Lam as A Plant Biofilter

Objective This work is an evaluation of the efficiency of a sand-gravel or unwoven fabric bed system and Lolium perenne Lam as plant biofilter in the reduction of solids and nutrients removal from aquaculture discharge water. Methods The fzrst step consisted of the collection of wastewater in the tank and the distribution at three different hydraulic loading regimes （0.5, 1, 1.5 L/hour） to the different experimental systems. The second step was to evaluate the performance of the different systems. The fzrst system consisted of a bucket filled with a substrate of sand/gravel （20 cm in depth）, on the bottom of which was a 80 mesh/inch2 of nylon （S1）; the second was similar, but was planted with Lolium perenne lam （S2）; the third was planted with a grass plate consisting of 7 layers of unwoven fabric planted with L. perenne （S3）. Results The second system showed the best performance in reducing solids as well as in nutrients （TN, TP, and COD） reduction. The removal rates for TS, TN, and TP were negatively correlated with the loading regimes, with 0.5 L/hour being the most efficient and thus taken as the reference. Conclusions Solids management using a sand/gravel substrate as bed culture and Lolium perenne L. as plant biofilter has proved to be an efficient technique for solids reduction with low operating cost. This grass plays an important role in wastewater eco-treatment by absorbing dissolved pollutants （TAN） as nutrients for its growth.

Genome-wide markers for seed yield and disease resistance in perennial ryegrass

The market success of perennial ryegrass(Lolium perenne L.) cultivars depends on sufficient seed production, as they are propagated by seed. However, breeding for high quality forage production reduces seed yield, and breaking the negative correlation would help to overcome the problem. The foliar disease crown rust is another factor affecting reproductive capacity and thereby seed yield. We evaluated seed yield-related traits and resistance to crown rust in a collection of commercial cultivars and ecotypes of perennial ryegrass and identified genome-wide markers associated with the traits. The study revealed high variation between the ecotype and cultivar groups as well as between years. A genome-wide association study identified 17 DNA single-nucleotide polymorphisms(SNPs) of which eight were associated with crown rust and nine with flag-leaf length. The SNP markers were located within or near predicted genes functioning in defense against pathogens. The identified genes are strong candidates for a further in-depth functional study to continue unravel determination of leaf architecture and crown rust resistance in perennial ryegrass.

Effects of Condensed Tannins from Quebracho Extract on the Kinetic of in vitro Gas Production on Trifofium repens, Lotus corniculatus and Lofium perenne

The aim of this work was to study the effect of condensed tannins （CT） on the kinetic of gas production in vitro, on the three main species of Azorean pasture： Trifolium repens, Lotus corniculatus and Lolium perenne, using Quebracho extract as the source of CT, and also to calculate total tannins and condensed tannins on the species studied. Lotus corniculatus, Lolium perenne and Trifolium repens were tested in vitro with the inclusion of Quebracho extract in doses of 0%, 2.5% and 5% DM. The total content in tannins was determined in the 3 species. We have found, in comparison with standard tannic acid, that tannins exist in the flower of T. repens （0.81 equivalents of tannic acid） and in L .corniculatus （1.07 equivalents of tannic acid） but not in L .perenne （0 equivalents of tannic acid）. The concentration of condensed tannins in the 3 species was： 0.34 mg/mL for T. repens; 0.83 mg/mL for L. corniculatus and 0 mg/ml for L. perenne. We verified that a significant reduction （P 〈 0.05） of gas production happened for doses of 5% of CT in comparison with the other two concentrations： 0% and 2.5% of CT. The results of this study express a reduction of the fermentation rate, which implies a reduction of gas production, so, a reduction of methane emission to the atmosphere and an increase of exploitation of the protein by ruminants.

外源褪黑素对干旱胁迫下多年生黑麦草幼苗生理特性的影响

为了研究外源褪黑素(MT)对干旱胁迫下多年生黑麦草幼苗生长的影响,试验以多年生黑麦草为材料,先以叶片喷施法施加外源MT,再采用控水法进行干旱胁迫,共设置6个处理,即CK(干旱+喷施纯化水)、T1(干旱+喷施50μmol/L MT)、T2(干旱+喷施100μmol/L MT)、T3(干旱+喷施150μmol/L MT)、T4(干旱+喷施200μmol/L MT)、T5(干旱+喷施250μmol/L MT),在干旱胁迫第0,3,6,9,12天取样,测定叶绿素a、叶绿素b、游离脯氨酸(Pro)、可溶性糖、丙二醛(MDA)含量,以及过氧化物酶(POD)、超氧化物歧化酶(SOD)、过氧化氢酶(CAT)活性。结果表明:在干旱胁迫第3,6,9,12天,T1、T2、T3处理的叶绿素a(除第9天T2处理外)和叶绿素b(除第3,6,9天T1处理外)含量均显著高于CK处理(P<0.05),其中T3处理的叶绿素a、叶绿素b含量均最高;在干旱胁迫第6,9,12天,T3处理的MDA含量显著低于其他处理(P<0.05);在干旱胁迫第12天时,T3处理的Pro含量和T4处理的可溶性糖含量均显著高于其他处理(P<0.05),相较于CK处理增加了31.7%和50.4%;干旱胁迫第9天时,T3处理的POD和CAT活性均显著高于其他处理(P<0.05),相较于CK处理分别提高了41.4%和21.3%;干旱胁迫第12天时,T3处理的SOD活性显著高于其他处理(P<0.05)。说明添加外源MT有助于减轻干旱胁迫下多年生黑麦草幼苗的膜质损伤,提高叶绿素及有机渗透调节物质的含量,缓解植物失水带来的损伤,从而增强多年生黑麦草对干旱胁迫的耐受性。在本试验条件下,喷施150μmol/L MT溶液的效果最好。

三叶草根浸提液对3种牧草种子萌发及幼苗生长的影响

为探索三叶草的防控及利用提供理论依据,采用培养皿生物测定法分析,研究不同浓度(0、2.5、5.0、10.0 g·L-1)三叶草根浸提液对黑麦草(Lolium perenne)、高羊茅(Festuca arundinac)和赖草(Leymus secalinus)种子萌发及幼苗生长的化感作用,以及三叶草(Trifolium repens)的生长竞争力和成功入侵原因。结果表明,三叶草根浸提液对3种牧草种子萌发(发芽率、发芽指数)和幼苗生长(根长、苗长、根干重、苗干重)均有化感作用,且其化感作用效应存在一定的差异。三叶草根浸提液对黑麦草种子萌发具有抑制作用,对高羊茅和赖草的种子萌发有“低促高抑”作用,对黑麦草根长和干重、苗高和干重均具有抑制作用,对高羊茅和赖草则表现为低浓度的促进、高浓度的抑制效应。从综合化感效应指数来看,随着三叶草根浸提液浓度的增加,对黑麦草具有抑制作用,而对高羊茅和赖草有“低促高抑”的双重作用。3种供试牧草对三叶草根浸提液的敏感程度也有差异,表现为:黑麦草>高羊茅>赖草。入侵植物三叶草根浸提液对3种牧草的化感效应较为明显,在入侵严重的地方,可选择补播耐受力强的牧草。

双聚材料对干旱条件下多年生黑麦草幼苗生长的影响

干旱是限制工程创面植物生长发育的关键环境因子,双聚材料(Double polymers SJ)是用于边坡土体防渗固化的新型材料,对于工程扰损区植被恢复具有重要意义。本研究选择黑麦草(Lolium perenne L.)为研究材料,采用盆栽试验,分析不同干旱条件下SJ对黑麦草生长的影响,结果表明:中、重度干旱处理显著降低了黑麦草存活率、植株含水量及叶绿素含量,增加了植株·O^(2-)、H_(2)O_(2)、MDA等毒性物质的积累。添加SJ一方面提高了土壤的保水性(蒸发量减少约50%),另一方面显著增加了黑麦草植株的含水量和叶绿素含量,并降低了活性氧等有毒物质含量,有利于黑麦草生物量的积累及存活率的提高。因此,SJ的保水性及其对植物生长的促进作用,有利于干旱区工程边坡的生态修复。

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。

Lolium属黑麦草形态特征、种子细胞结构及其侵染病菌

通过对黑麦草植株、种子形态特征和内部细胞结构进行研究分析,并对其籽实是否含有诸如可使毒麦籽实产生毒麦硷(Temuline-C7H12N2O)的相关病菌进行了探讨,为口岸杂草检验检疫以及引进和发展优质牧草提供依据.