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。

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.

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.

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.

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.

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。

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.

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。

多年生黑麦草VQ家族基因的鉴定及分析

VQ(Valine-glutamine)是植物特有的一类蛋白,在植物生长发育及抵御生物与非生物胁迫中发挥着重要作用,但在多年生黑麦草(Lolium perenne L.)中鲜有VQ基因的相关研究报道。本研究利用生物信息学方法在多年生黑麦草基因组中鉴定了52个LpVQ基因,其不均匀地分布于7条染色体上。亚细胞定位结果显示,LpVQ蛋白主要定位于细胞核,仅LpVQ45定位于细胞膜。系统进化分析表明,LpVQ基因被分为7个亚家族,与拟南芥(Arabidopsis thaliana(L.)Heynh.)只存在4对直系同源基因。基因结构分析结果表明,46个LpVQ基因无内含子。荧光定量PCR分析结果显示,从各亚家族中随机选取的21个LpVQ基因不同程度地响应黑暗、高温及盐胁迫,且在胁迫早期快速响应。

氧化石墨烯对黑麦草种子内生真菌群落结构和多样性的影响

为了探究氧化石墨烯(GO)对黑麦草种子内生真菌群落结构和多样性的影响,将黑麦草种子在0.4%、0.8%和1.2%水平的GO溶液中胁迫4 d,采用高通量测序技术,分析GO胁迫下黑麦草种子内生真菌群落组成和多样性的变化。结果显示,4个样本所有样品共分离获得303种真菌,归属于10门39纲84目160科240属。在门分类水平上,子囊菌门(Ascomycota)和担子菌门(Basidiomycota)是主要的内生真菌类群;在属分类水平上,各处理的共有优势菌属为链格孢属(Alternaria)。不同GO处理黑麦草种子内生真菌群落结构存在差异,随着GO浓度的增加,子囊菌门的丰度出现下降,0.8%和1.2%GO处理较对照分别显著降低了19%和20%(P<0.05);所有GO处理的担子菌门丰度均显著高于对照(P<0.05);1.2%处理链格孢属的丰度较对照显著降低了37.36%。与对照相比,1.2%GO处理内生真菌的丰富度和多样性显著增加,ACE、Chao1和Shannon指数分别增加了123.5%、127.4%和117.5%(P<0.05)。主坐标分析(PCoA)分析表明,1.2%GO处理内生真菌群落结构与其他处理有较大差异;线性判别分析(LEfSe)分析发现,各处理差异指示种明显不同。可见,GO改变了黑麦草种子内生真菌群落的组成和多样性,尤其是高浓度处理(1.2%)。研究可为碳纳米材料暴露对共生物种的潜在影响研究提供参考。

果树凋落叶浸提液对多年生黑麦草和紫花苜蓿的化感效应

【目的】探讨陕北地区红枣、核桃及苹果凋落叶的化感效应,为选择经济林下适生草种提供理论指导。【方法】以室外盆栽牧草多年生黑麦草和紫花苜蓿为材料,设置不同浓度红枣、核桃和苹果凋落叶浸提液(0.1,0.05,0.025,0.0125 g/mL)处理,测定牧草生长和生理指标。【结果】(1)牧草单株干质量在3类凋落叶各浓度浸提液处理下大多比对照显著降低,且红枣浸提液的降幅较小。(2)牧草丙二醛含量在3类浸提液处理下均高于对照,而红枣浸提液的增幅较小,其叶绿素含量、抗坏血酸含量和抗氧化酶活性变化在3类浸提液间存在明显差异,且多年生黑麦草的变幅明显大于紫花苜蓿。(3)3类浸提液对牧草根系性状的影响存在明显差异,均抑制其根长生长,明显抑制多年生黑麦草根尖数,而促进紫花苜蓿根尖数。【结论】3种果树凋落叶浸提液对2种牧草生长多表现出显著抑制作用,并以红枣浸提液的抑制作用最小,且多年生黑麦草生长受抑制程度小于紫花苜蓿。

镉胁迫对3种草坪草生理特性及叶片超微结构的影响

重金属胁迫是常见的环境胁迫之一,对植物的生长发育及其生产力和生态功能具有重大影响。为探究不同草坪草种对镉胁迫的生理差异及耐性机制,并将其合理应用至景观营造,本研究以白三叶(Trifolium repens)、高羊茅(Festuca arundinacea)和黑麦草(Lolium perenne)为试验材料,采用盆栽试验法,将Cd2+处理浓度设置为:0,200,500,1 000,2 000 mg·kg^(-1)。经处理60 d后测定草坪草各项生理指标并观察叶片细胞超微结构。结果表明:随Cd2+浓度增加,3种草坪草的光合色素含量呈下降趋势,超氧化物歧化酶(Superoxide dismutase, SOD)、过氧化物酶(Peroxidase, POD)活性和丙二醛(Malondialdehyde, MDA)含量总体上为上升趋势,过氧化氢酶(Catalase, CAT)活性呈先升后降趋势;高浓度的镉胁迫对3种草坪草叶片超微结构造成损伤,其叶绿体内基粒片层结构模糊或溶解,部分细胞发生质壁分离。因此,建议在Cd污染较重的土壤选用高羊茅和黑麦草,Cd污染较轻的土壤选用白三叶。