The Effect of Light Intensity during Growth on the Subsequent Rate of Photosynthesis of Leaves of Tall Fescue (Festuca arundinacea Schreb.)

Leaves of tall fescue (Festuca arundinacea Schreb.) plants grownin bright light had higher rates of apparent photosynthesisper unit leaf area in bright light, and slightly lower ratesin dim light than did those of plants grown in dim light. Darkrespiration rates were higher in plants grown in bright lightthan in plants grown in dim light and the decline of photosynthesiswith increasing leaf age was faster. The rate of apparent photosynthesis in bright light of the firstleaf to become fully expanded after plants were transferredfrom bright to dim light was lower than that of plants remainingin bright light. The decline in the rate of photosynthesis ofa leaf already fully expanded at the time of transfer was notaffected. Transferring from dim to bright light increased therate of photosynthesis of the next expanded leaf; it also increasedthe rate of an already fully expanded leaf during the firstweek in bright light. After this, photosynthesis fell at a ratesimilar to that of plants remaining in dim light.     

Temperature Effects upon Inflorescence and Seed Development in Tall Fescue (Festuca arundinacea Schreb.)

The effects of three temperatures 15, 20, and 25 °C uponinflorescence and seed development in tall fescue (Festuca arundinaceaSchreb) between inflorescence emergence and seed maturity werestudied. Increasing temperature over this range reduced culmlength and the number of florets per spikelet, hastened theonset of anthesis and pollen release, increased relative growth-rateof the florets 9 days after peak anthesis, reduced the periodof seed development and 1000 seed weight No large effects oftemperature upon the percentage of florets setting seed werefound. The practical implications of these results are discussed.     

土施多效唑对高羊茅生长的效应

土施条件下,多效唑用量与高羊茅生长速率存在显著的二次函数关系,其矮化效应随着多效唑用量的增大而增大,剂量超过0.65g·m-2时效应减弱;植株地上部生物量和生长速率有类似关系,剂量超过0.8g·m-2时效应不显著,但地下部生物量随多效唑供给量增加而递减。多效唑低于0.35g·m-2的高羊茅叶色深绿,超过此剂量叶片即枯黄,且随着剂量增大而更加严重。高羊茅叶片总含水量随着多效唑用量增大而减小,但在干旱胁迫条件下,叶中总含水量随着多效唑用量增大而增大;束缚水含量也有上升。高羊茅在严重干旱后的生长恢复能力随着多效唑用量增大而增大,超过0.95g·m-2时即下降。     

The Effects of Nitrogen Fertilization and the Growing Season on Photosynthesis of Field-grown Tall Fescue (Festuca arundinacea Schreb.) Canopies

Canopy gross photosynthesis of tall fescue receiving three tofour rates of N fertilization was studied under field conditionsduring three contrasting growing seasons. Under non-limitingN growing conditions, the growing seasons did not have a significanteffect on the maximum canopy gross photosynthesis (canopy grossphotosynthesis at saturating PAR) and the maximum light yield(quantum efficiency of the canopy at low PAR). In the absenceof N fertilization and for a similar LAI, the values of themaximum canopy gross photosynthesis were approximately equalto 70% of those obtained under non-limiting N conditions. Thisresponse of the tall fescue canopy to N concentration is muchsmaller than that reported at the leaf level. The reductionin canopy photosynthetic capacity with no N applied comparedto non-limiting N conditions is much less than the reductionobserved previously in above-ground dry matter accumulation.The effect of N fertilization on above-ground dry matter accumulationis due primarily to changes in C partitioning and the resultingfaster leaf area development and greater light interceptionrather than the effect of N on the canopy photosynthetic capacityper se .Copyright 1993, 1999 Academic Press Festuca arundinacea Schreb., photosynthesis, nitrogen, grass, carbon     

The Effect of Age on the Rate of Apparent Photosynthesis in Leaves of Tall Fescue (Festuca arundinaceaSchreb.)

n apparatus is described in which the rate of apparent photosynthesisof single attached or detached grass leaves was determined bymeasuring with an infra-red gas analyser the uptake of carbondioxide from a stream of air passed over the leaves. In one experiment the apparatus was used to determine the apparentphotosynthesis at one time of the three youngest leaves removedfrom a tiller of tall fescue plants grown in the field. Resultsshowed that each older leaf had a lower rate of apparent photosynthesisthan its successor. To determine the real effect of age of theleaf without any possible interaction with position of the leafor an after-effect of environment, measurements of apparentphotosynthesis were made in two further experiments on leavesattached to the main stem on plants grown in controlled environments.Results were obtained from samples of the fifth leaf of increasingage from full expansion. These showed a progressive declinein apparent photosynthesis with increasing age: in one experimentthis was preceded by a small initial rise after complete leafexpansion. There were no marked changes in the weight of theleaf as it aged and, in consequence, the form of the resultswere similar when expressed on either a leaf area or dry weightbasis.     

高羊茅叶片表皮蜡质含量与其抗旱性的关系

以14个高羊茅品种为试验材料,在田间试验中对干旱高温胁迫下的叶片表皮蜡质含量、净光合速率、蒸腾速率、气孔导度、胞间CO2浓度等生理指标测定分析。结果表明,干热胁迫下高羊茅品种间的叶片表皮蜡质含量和水分利用效率均存在极显著差异(P<0.01);叶片蜡质含量与综合抗旱性和水分利用效率的等级相关系数分别为0.78(P<0.01)和0.68(P<0.01);蜡质含量越高的品种,其叶片气孔导度和胞间CO2浓度越低,水分利用效率越高,但所有品种的水分利用效率绝对值都较低。研究发现,在干热胁迫时,高羊茅叶片表皮蜡质可通过对气孔导度的调节来减少气孔蒸腾,提高水分利用效率,最终提高其抗旱性;表皮蜡质含量可以作为高羊茅品种抗旱性鉴定的一个新指标。     

The Effects of Nitrogen Fertilization and the Growing Season on Carbon Partitioning in a Sward of Tall Fescue (Festuca arundinacea Schreb)

The effect of N fertilization on the relative carbon partitioningto the roots of tall fescue (Festuca arundinacea Schreb ), grownunder field conditions, was studied with a ¹⁴C-labelling techniqueon three regrowths representing contrasting growing seasonsUnder non-limiting N growing conditions, the relative carbonpartitioning to the roots averaged 17.0, 15 8, and 11 1% inthe summer, autumn, and spring regrowths, respectively The relativecarbon partitioning to the roots increased during the summerand autumn regrowths but decreased during the spring regrowthIn the absence of N fertilization, the relative carbon partitioningto the roots averaged 31 3, 26 5, and 26 7 in the summer, autumn,and spring regrowths, respectively The results were interpretedin terms of a functional equilibrium between the shoots andthe roots It was concluded that, for a dense canopy of a perennialgrass growing under fluctuating conditions of solar radiationand temperature, the relative growth of the roots compared tothe relative growth of the total biomass is primarily a functionof the shoot biomass Festuca arundinacea Schreb, carbon, partitioning, nitrogen, root growth, fertilization, grass     

Ascorbic Acid Enhances the Accumulation of Polycyclic Aromatic Hydrocarbons (PAHs) in Roots of Tall Fescue (Festuca arundinacea Schreb.)

Plant contamination by polycyclic aromatic hydrocarbons (PAHs) is crucial to food safety and human health. Enzyme inhibitors are commonly utilized in agriculture to control plant metabolism of organic components. This study revealed that the enzyme inhibitor ascorbic acid (AA) significantly reduced the activities of peroxidase (POD) and polyphenol oxidase (PPO), thus enhancing the potential risks of PAH contamination in tall fescue (Festuca arundinacea Schreb.). POD and PPO enzymes in vitro effectively decomposed naphthalene (NAP), phenanthrene (PHE) and anthracene (ANT). The presence of AA reduced POD and PPO activities in plants, and thus was likely responsible for enhanced PAH accumulation in tall fescue. This conclusion is supported by the significantly enhanced uptake of PHE in plants in the presence of AA, and the positive correlation between enzyme inhibition efficiencies and the rates of metabolism of PHE in tall fescue roots. This study provides a new perspective, that the common application of enzyme inhibitors in agricultural production could increase the accumulation of organic contaminants in plants, hence enhancing risks to food safety and quality.     

Carbon Balance of Tall Fescue (Festuca arundinacea Schreb.): Effects of Nitrogen Fertilization and the Growing Season

The C balance of a tall fescue sward grown under different ratesof N fertilization in summer, autumn, and spring was calculatedusing models derived from measurements of shoot growth, canopygross photosynthesis, shoot respiration and of C partitioningto the roots. Under the diverse growing conditions associatedwith the seasons and the N fertilization, C utilization forabove- and below-ground biomass accumulation never exceeded39 and 14% of the canopy gross photosynthesis, respectively.Carbon losses attributed to root respiration and exudation,which were estimated by difference between canopy net photosynthesisand total growth, ranged between 3 and 30% of canopy gross photosynthesis.Seasonal differences in shoot growth could be attributed tothe amount of intercepted radiation, the radiation-use efficiencyand the C partitioning to the roots. The effect of N deficiencyon shoot growth can be attributed to its effects on canopy photosynthesis(principally resulting from changes in intercepted photosyntheticallyactive radiation) and C partitioning. In comparison with theeffect on shoot growth, the effect of the N deficiency on thecanopy gross photosynthesis per unit of light intercepted overthe regrowth cycle was limited. It is concluded that most ofthe effect of N fertilization on shoot growth is due to changesin C partitioning which result in faster leaf area developmentand greater light interception.Copyright 1994, 1999 AcademicPress Tall rescue, Festuca arundinacea Schreb., carbon balance, nitrogen, grass, fertilization     

The Effects of Shaking on the Growth and Water Relations of Festuca arundinacea Schreb

The extension growth of Festuca arundinacea was reduced by shaking,and the leaves formed during shaking were thinner and narrowerthan the controls. The response to shaking was modified by thenutritional status of the plant — shaken plants took upmore phosphorus from a phosphorus deficient soil than the controlsand this advantage seemed to offset the influence of shaking. Shaken plants displayed a higher stomatal conductance and alower water potential than the controls, though it was consideredthat the effect of shaking could not be attributed entirelyto differences in water potential. Festuca arundinacea Schreb., water potential, stomatal conductance, phosphorus, shaking     

Convergence of Goals: Phylogenetical,Morphological, and Physiological Characterization of Tolerance to Drought Stress in Tall Fescue (Festuca arundinacea Schreb.)

The aim of this study is to find Iranian tall fescue accessions that tolerate drought stress and investigation on phylogenetical, morphological, and physiological characterization of them. For this propose, inter-simple sequence repeats (ISSR) markers were used to examine the genetic variability of accessions from different provinces of Iran. Of 21 primers, 20 primers generated highly reproducible fragments. Using these primers, 390 discernible DNA fragments were produced with 367 (93.95 %) being polymorphic. The polymorphic information content (PIC) values ranged from 0.948 to 0.976, with a mean PIC value of 0.969. Probability identity (PI) and discriminating power (D = 1 ? PI) among the primers ranged from 0.001 to 0.004 and 0.998 to 0.995, respectively. A binary qualitative data matrix was constructed. Data analyses were performed using the NTSYS software and the similarity values were used to generate a dendrogram via UPGMA. To study the drought stress, plants were irrigated at 25 % FC condition for three times. Fresh leaves were collected to measure physiological characters including: superoxide dismutase, catalase, and peroxidase activities and proline and total chlorophyll content at two times, before and after stress application. Relative water content, fresh and dry weight ratio, survival percentage, and visual quality were evaluated after stress. Morphological and physiological characters were assessed in order to classify accessions as either tolerant or sensitive using Ward’s method of Hierarchical cluster analysis in SPSS software. The results of present study demonstrated that the ISSR markers are useful for studying tall fescue genetic diversity. Convergence of morphological and physiological characterizations during drought stress and phylogenetic relationship results showed that accessions can be grouped into four clusters; drought-tolerant accessions that collected from west of Iran, drought-tolerant accessions collected from northwest of Iran, drought semi-tolerant accessions collected from center of Iran, and drought-sensitive accessions collected from north of Iran. Data presented could be used to classify the tall fescue accessions based on suitability of cultivation in the regions studied or the regions with the similar environmental condition.     

The Effect of Wind on Grasses II. Mechanical Damage in Festuca arundinacea Schreb

After a period of exposure to wind in a wind tunnel, two aspectsof the resulting mechanical damage in Festuca arundinacea Schreb.var. S170 were examined. These were the frequency of occurrenceof transverse fold lines and the microscopic nature of leafabrasion marks. Transverse fold lines were found to be of morefrequent occurrence in wind-exposed plants. A stereoscan electronmicroscope was used to show the severe damage to the leaf surfacethat can result from leaves rubbing over each other. Some possibleconsequences of such damage are discussed.     

Correction to: Isolation,Characterization, and Expression Profiling of Nucleoside Diphosphate Kinase Gene from Tall Fescue (Festuca arundinacea Schreb.) (FaNDPK) under Salt Stress

Plant Molecular Biology Reporter - The original version of this article unfortunately contained some mistakes in article Title and Table 1.     

The Effect of Wind and a Reduced Supply of Water on the Growth and Water Relations of Festuca arundinacea Schreb

Festuca arundinacea was grown at high and low wind-speeds attwo levels of soil water. Transpiration was increased at highwind-speed and accompanied by leaf water stress. Growth of leafarea was progressively reduced according to the severity ofthe experimental treatments in the sequence: wet soil and lowwind; dry soil and low wind; wet soil and high wind; dry soiland high wind. The leaf water potential was also reduced inthis sequence. Festuca arundinacea Schreb., transpiration, water stress, wind, water potential     

9个高羊茅品种初期生长对镉胁迫的响应

用Cd²⁺浓度0（对照）、25、50、75 mg/L分别处理9个高羊茅品种种子,测定供试品种种子发芽势、发芽率、幼苗苗高、根长、鲜重、叶绿素含量、丙二醛含量、质膜透性等8项指标,比较9个品种耐镉性。结果表明:与对照相比,在不同浓度Cd²⁺胁迫下,家园的发芽势和发芽率以及麦哲伦鲜重呈先略上升后下降趋势,其余品种的均呈下降趋势;9个高羊茅品种幼苗根长、苗高、叶绿素含量均呈下降趋势;9个高羊茅品种丙二醛含量和质膜透性均呈上升趋势。对测定的8项指标进行综合评价结果显示:在Cd²⁺25 mg/L胁迫下,9个品种耐Cd²⁺性由强到弱的顺序为热浪>翠碧A>里园2号>缤狗>麦哲伦>家园>宇宙星>回报>爱瑞3号;在Cd²⁺50 mg/L胁迫下,耐Cd²⁺性的顺序为热浪>翠碧A>缤狗>麦哲伦>里园2号>家园>宇宙星>爱瑞3号>回报;在Cd²⁺ 75 mg/L胁迫下,耐Cd²⁺性的顺序为热浪>缤狗>里园2号>翠碧A>家园>麦哲伦>爱瑞3号>宇宙星>回报。所以,在治理Cd²⁺污染土壤时,要根据污染严重程度,合理选用高羊茅品种。     

The Effect of Wind and a Reduced Supply of Phosphorus and Nitrogen on the Growth and Water Relations of Festuca arundinacea Schreb

Festuca arundinaceae was grown at high and low wind-speed attwo levels of either soil phosphorus or soil nitrogen. At increasedwind-speed, mean relative growth rate and leaf extension ratewere reduced when plants were grown with high nutrient concentrationsand further reduced when phosphorus or nitrogen stress was imposedon the plants. Transpiration was increased at high wind-speedexcept under conditions of phosphorus stress, where the ratewas actually decreased. Relationships between water stress,wind and nutrient status are discussed, especially in relationto the possible role of phosphorus stress in causing sclerophylly. Festuca arundinacea Schreb., relative growth rate, water stress, wind, nitrogen, phosphorus, sclerophylly     

Degradation of Chlorophyll in the Leaves of Reed Fescue (Festuca arundinacea) under the Action of Volatile Organic Compounds and Benzo(a)pyrene

Biology Bulletin - The pathways of chlorophyll a and b degradation were studied in the leaves of reed fescue (Festuca arundinacea) under the action of volatile organic compounds (pentane, hexane,...     

The After-effect of Wind on the Photosynthesis and Transpiration of Festuca arundinacea

The after-effect of wind on photosynthesis and transpiration of Festuca arundinacea Schreb, was determined. Following a period of exposure In a controlled environment wind tunnel the wind-treated plants showed reduced rates of photosynthesis when compared with the controls under standard conditions. Evaporation from paper model tillers was measured and the boundary layer resistance was shown to be low in all but very low wind speeds. Analysis of CO₂ and H₂O diffusion pathways indicated that mesophyll resistance in wind-treated plants was higher whilst leaf surface resistance was lower than in the controls. The high mesophyll resistance in the wind-treated plants was attributed to reduced water content.     

Metabolism and subcellular distribution of anthracene in tall fescue (Festuca arundinacea Schreb.)

Aim

Understanding the uptake processes of organic contaminants by plants is essential when assessing crop contamination and subsequent human exposure. Unfortunately, limited information is available on plant metabolism and subcellular distribution of polycyclic aromatic hydrocarbons (PAHs), a group of highly toxic organic contaminants with carcinogenic, mutagenic, and teratogenic properties. Thus we seek to investigate the metabolism and intracellular distribution of PAH in tall fescue (Festuca arundinacea Schreb.).

Methods

This work was conducted utilizing greenhouse hydroponical experiments. Seedlings of tall fescue were firstly cultured in half-strength Hoagland solution with anthracene (ANT). Then treated plants were removed from the ANT-spiked solution, and transplanted into solutions free of ANT. After 0–16 days, the seedlings were sampled and prepared for ANT analysis. Seedlings were washed using Milli-Q water and then separated into different parts to measure ANT distributions at the subcellular level.

Results

ANT concentrations and dissipation amounts in root and shoot of tall fescue decreased in 0–16 days after transplantation from an ANT-spiked culture solution to a solution free of PAH, revealing ANT metabolism in the plant. The accumulation of the examined primary metabolites of ANT, i.e., anthrone and anthraquinone, against time also supported plant metabolism of ANT. About 10 % of ANT resided in the plants at 8–16 days due to the formation of ANT-bound residues with plant tissues. ANT concentrations in the cell walls and organelles of plant roots and shoots decreased significantly during the 16-day period. Cell walls and organelles were the dominant storage compartments for ANT and anthraquinone in plants at 16 days, whereas the distribution of anthrone at 16 days in root cells was ordered as cell organelles >cell soluble fraction >cell wall and in shoot cells as cell soluble fraction >> cell organelle ? cell wall. Although the organelle content is smaller, the concentrations of ANT and metabolites in the organelle fraction were much higher than those in cell walls.

Conclusions

This was a primary investigation into the metabolism and intracellular distribution of PAH in plant. We demonstrated the metabolism of ANT in tall fescue based on the observed reduced concentrations, dissipated amounts, and detected metabolites. ANT and its metabolites were distributed into the cell water-soluble fraction, cell walls, and organelles. Results of this work will enhance the understanding of PAH transfer and transformation in plants and will be valuable for risk assessments of plant contamination at polluted sites.