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。

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.

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.

Photosynthetic pigments and photosynthetic products of endophyteinfected and endophyte-free Lolium perenne L.under drought stress conditions

Endophyte-infected(EI)seeds of Lolium perenne L.were used to attain endophyte-free(EF)population by heating the seeds at 43℃for 15 min and then 57℃for 25 min.Relative water content(RWC),chlorophyll,soluble sugar and starch content of EI and EF populations under normal and drought stress conditions were compared to investigate the effect of endophyte infection on the host plant.Under severe stress,RWC of EI leaf was significantly higher than that of EF leaf,i.e.EI plants took more advantages over EF plants in water-holding ability.Under mild stress,endophyte could enhance soluble sugars in host plants to improve their osmotic ability.With stress intensification,the improvement of endophyte no longer existed,and more photosynthetic products(such as starch)accumulated in EI plants to survive through the undesirable conditions.In the next spring,EI populations will recover more rapidly than EF populations.The biomass of a population is closely related to its photosynthesis.Under severe stress,EI population significantly accumulated more biomass than EF population.As far as photosynthetic pigments were concerned,contents of Chla,Chlb and Car of EI plants were close to those of EF plants,which suggested that endophyte infection didn’t alleviate photosynthetic pigments from being destroyed by drought stress,and endophyte might improve photosynthesis ability of its host plant in other ways.

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。

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.

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.

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.

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。

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。

多年生黑麦草质膜型水通道蛋白基因LpAQP的克隆及功能分析

【目的】研究黑麦草在逆境胁迫下水分代谢的基因调控,克隆黑麦草质膜型水通道蛋白基因的全长cDNA序列,并对其表达模式进行研究。【方法】利用RACE技术从黑麦草(品种"顶峰")中获得LpAQP全长cDNA序列;运用生物信息学软件分析其编码蛋白;构建LpAQP与GFP融合的瞬时表达载体,采用基因枪法转入洋葱表皮细胞,观察其细胞定位;通过real time-PCR分析LpAQP的表达模式,并用Southern杂交分析其拷贝数。【结果】克隆获得LpAQP的cDNA序列,GenBank登录号为JX569791,其开放阅读框(ORF)为867 bp,编码288个氨基酸,蛋白质分子量为30.7 kD。该基因含有2个NPA单元,6个跨膜区,LpAQP含有与MIP家族完全一致的蛋白质保守区,其氨基酸序列与其它禾本科PIP类质膜型水通道蛋白同源性较高。物种间聚类分析表明LpAQP与大麦、小麦质膜型水通道蛋白同源性较高。LpAQP可能定位于细胞质膜上。通过Southern杂交分析,发现LpAQP在黑麦草基因组中以单拷贝存在。real time-PCR分析表明LpAQP在黑麦草茎部表达高于叶和根,持续干旱胁迫会导致LpAQP表达量先上调后下降。【结论】克隆获得黑麦草质膜型水通道蛋白基因LpAQP,其以单拷贝形式存在,在黑麦草根、茎、叶中均有表达,尤其是茎中表达最高。其表达受干旱胁迫影响。

NaCl胁迫下黑麦草种子萌发过程中DNA甲基化与基因表达分析

为了解黑麦草(Lolium perenne)种子在正常条件与NaCl胁迫下萌发过程中DNA甲基化动态变化以及重要盐胁迫相关基因的表达。运用甲基化敏感扩增多态性技术分析对照和150 mmol·L^(-1)NaCl处理下黑麦草种子萌发过程(0,1,2,4,7 d)的DNA甲基化水平及动态变化,并通过实时荧光定量PCR(QRT-PCR)检测8个重要的盐胁迫相关基因的表达情况。结果表明:黑麦草种子萌发过程中甲基化水平呈下降趋势,以双链甲基化方式为主,甲基化变化同时发生在编码序列和非编码序列中。NaCl处理下DNA甲基化程度高于CK,而去甲基化程度低于CK,最终导致NaCl处理下基因组净的甲基化位点数目增加。黑麦草种子耐盐萌发过程中代谢增强,8个盐胁迫相关基因表达量呈上升趋势,而NaCl胁迫延缓了种子萌发进程,在大多数时间点的基因表达低于对照。

镉(Cd)污染土壤接种丛枝菌根真菌(Glomus mosseae)对黑麦草生长和光合的影响

研究镉(Cd)污染土壤中接种丛枝菌根真菌Glomus mosseae对黑麦草(Lolium porenne L.)生长、根系活力、叶片膜质过氧化程度和叶绿素含量以及光合特性的影响。结果表明:镉污染降低了黑麦草的根系活力和根系生长,叶片丙二醛(MDA)含量和相对电导率增加,叶绿素含量降低。接种Glomus mosseae的黑麦草根系的菌根侵染率达50%～70%,同没有接种Glomus mosseae的黑麦草相比较,镉污染条件下黑麦草的根系活力增强,叶片的叶绿素增加,叶片膜质的过氧化程度减轻。镉污染条件下,Glomus mosseae侵染后的黑麦草叶片光合速率和气孔导度增加,提高了黑麦草的生物生长量。因此,接种Glomus mosseae改善了黑麦草耐镉的生长特性,而且增强了耐镉的生理功能,降低了镉对黑麦草的毒害。