scholarly journals Do Phytomer Turnover Models of Plant Morphology Describe Perennial Ryegrass Root Data from Field Swards?

Agriculture ◽  
2016 ◽  
Vol 6 (3) ◽  
pp. 28 ◽  
Author(s):  
Cory Matthew ◽  
Alec Mackay ◽  
Arif Robin
Keyword(s):  
Perennial Ryegrass ◽  
Plant Morphology ◽  
Turnover Models

scholarly journals Plant morphology differences in two perennial ryegrass cultivars

2009 ◽  
Vol 52 (4) ◽  
pp. 391-398 ◽  
Author(s):  
A. M. Sartie ◽  
H. S. Easton ◽  
C. Matthew
Keyword(s):  
Perennial Ryegrass ◽  
Plant Morphology

scholarly journals Plant responses to defoliation and relationships with pasture persistence

2011 ◽  
Vol 15 ◽  
pp. 39-46
Author(s):  
G.R. Edwards ◽  
D.F. Chapman
Keyword(s):  
Perennial Ryegrass ◽  
White Clover ◽  
Plant Morphology ◽  
Farming Systems ◽  
Plant Responses ◽  
Plant Interactions ◽  
Trade Offs ◽  
Competition For Light ◽  
Grazing Systems

The effects of defoliation on plant morphology and the structure of perennial ryegrass and white clover populations are reviewed with reference to the persistence of yield in sown pastures. Maintenance of high densities of perennial ryegrass tillers and white clover stolons is fundamental to persistence. Tiller and stolon population densities are subject to within- and between-year variation, and are strongly influenced by defoliation management through processes such as competition for light, and size-density trade-offs mediated by self-thinning processes. Spring is a time when high tiller/stolon appearance and death rates occur simultaneously. Spring is also the time when clover populations undergo rapid structural change as large clover plants fragment to release small, unbranched plants with limited ability to compete for light with grasses. The central role of reproductive stem development in perennial ryegrass for summer survival of tillers and autumn re-establishment of tiller populations also highlights the importance of defoliation management during the spring for population persistence. Examples of the application of tactical defoliation management in spring, and at other times of the year, to manipulate stolon and tiller densities are presented. In some instances, such tactics may improve animal production potential, as well as the persistence of new cultivars. It is notable that the New Zealand literature on this topic is mostly more than 15 years old. Recent changes in farming systems and plant genotypes (e.g. tetraploidy in perennial ryegrass, late flowering perennial ryegrass) may require a reanalysis of established principles and practices related to defoliation x plant interactions in grazed pastures to ensure best possible pasture yield persistence and profitability of grazing systems. Keywords: grazing management, perennial ryegrass, persistence, population dynamics, white clover

Elevated CO2 causes large changes to morphology of perennial ryegrass (Lolium perenne)

2019 ◽  
Vol 70 (6) ◽  
pp. 555
Author(s):  
Rose Brinkhoff ◽  
Meagan Porter ◽  
Mark J. Hovenden
Keyword(s):  
Leaf Area ◽  
Elevated Co2 ◽  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Specific Leaf Area ◽  
Water Availability ◽  
Leaf Blade ◽  
Leaf Size ◽  
Plant Morphology ◽  
Relative Water

Plant morphology and architecture are essential characteristics for all plants, but perhaps most importantly for agricultural species because economic traits are linked to simple features such as blade length and plant height. Key morphological traits likely respond to CO2 concentration ([CO2]), and the degree of this response could be influenced by water availability; however, this has received comparatively little research attention. This study aimed to determine the impacts of [CO2] on gross morphology of perennial ryegrass (Lolium perenne L.), the most widespread temperate pasture species, and whether these impacts are influenced by water availability. Perennial ryegrass cv. Base AR37 was grown in a well-fertilised FACE (free-air carbon dioxide enrichment) experiment in southern Tasmania. Plants were exposed to three CO2 concentrations (~400 (ambient), 475 and 550 µmol mol–1) at three watering-treatment levels (adequate, limited and excess). Shoot dry weight, height, total leaf area, leaf-blade separation, leaf size, relative water content and specific leaf area were determined, as well as shoot density per unit area as a measure of tillering. Plant morphology responded dramatically to elevated [CO2], plants being smaller with shorter leaf-blade separation lengths and smaller leaves than in ambient (control) plots. Elevated [CO2] increased tillering but did not substantially affect relative water content or specific leaf area. Water supply did not affect any measured trait or the response to elevated [CO2]. Observed impacts of elevated [CO2] on the morphology of a globally important forage crop could have profound implications for pasture productivity. The reductions in plant and leaf size were consistent across a range of soil-water availability, indicating that they are likely to be uniform. Elucidating the mechanisms driving these responses will be essential to improving predictability of these changes and may assist in breeding varieties suited to future conditions.

Variation in turf-type morphological characters within Lolium perenne L. cv. Victorian

1989 ◽  
Vol 40 (4) ◽  
pp. 851 ◽  
Author(s):  
ME Rogers
Keyword(s):  
Tensile Strength ◽  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Heading Date ◽  
Plant Morphology ◽  
Morphological Characters ◽  
Leaf Length ◽  
Lolium Perenne L ◽  
Selection Strategies ◽  
Plant Collection

Aspects of plant morphology and flowering were measured in a spaced-plant collection of perennial ryegrass (Lolium perenne L.) cv. Victorian in order to assess the possibility of improving this cultivar for turf. The Victorian perennial ryegrass collection was also compared with a smaller collection of fine-leafed turf ryegrasses. Within cv. Victorian, positive phenotypic correlations were found betwecn the character�s leaf length and width, leaf length and sheath length, leafwidth and sheath length, leafwidth and leaf tensile strength, and leafiness (leaf number per unit ground area) and angle of growth. The correlated responses to selection were significant (P<0.001) for all characters, with the exception of heading date. Heritability values, calculated by using three methods, were also very high (>0.70). These heritabilities, combined with the fact that the variation found within Victorian ryegrass often encompassed the entire range in the turf ryegrass cultivars, indicate that an improved turf-type could be developed within cv. Victorian. However, some compromise must be made in selection strategies due to unfavourable correlations between the character's turf wear, assessed by using leaf tensile strength and appearance, and between vegetative growth and seed production.

scholarly journals The pasture ryegrass plant, what is it?

1991 ◽  
pp. 111-116
Author(s):  
J.L. Brock ◽  
V.J. Thomas
Keyword(s):  
Perennial Ryegrass ◽  
White Clover ◽  
Plant Density ◽  
Plant Morphology ◽  
Dry Weight ◽  
Grazing Management ◽  
Plant Structure ◽  
High Plant Density ◽  
Short Internodes ◽  
Average Size

Detailed studies of plant growth processes are important in understanding the performance and persistence of species in pastures, particularly in response to uncharacteristic environmental stress. The morphology of perennial ryegrass plants in mixed sheep grazed pastures was determined in self contained farmlets undercontrasting managements of rotational grazing, set stocking or a combination of both. Average size was 90 mg total DW, with 4- 5 tillers and 12-13 leaves, little different to white clover. Ryegrass exhibits strong clonal growth, with extension at the apex and death of the basal stem releasing branches to form new plants at regular intervals, maintaining a stable population structure of small plants all year. The normally short internodes on ryegrass stems can elongate to form stolon and elevate the apex to a more favourable position if survival is threatened. On average only 2530% of plants contained stolon at any one time. Because of high plant density the quantities of ryegrass stem present was often in excess of that produced by white clover in the same swards. Grazing management did not affect plant structure (numbers of tillers, leaves etc) only their size (dry weight), but had marked effects on pasture structure and subsequent survival of plants under stress. Keywords perennial ryegrass, plant morphology, grazing management, seasonal variation, plant survival, stolon formation

scholarly journals Changes in sward structure, plant morphology and growth of perennial ryegrass–white clover swards over winter

2021 ◽  
Author(s):  
C. Guy ◽  
T. J. Gilliland ◽  
D. Hennessy ◽  
F. Coughlan ◽  
B. McCarthy
Keyword(s):  
Perennial Ryegrass ◽  
White Clover ◽  
Plant Morphology ◽  
Winter Period ◽  
Stolon Length ◽  
Number Of Leaves ◽  
Trifolium Repens L ◽  
And Performance ◽  
Tiller Density ◽  
Sward Structure

White clover (Trifolium repens L.) is at a disadvantage to perennial ryegrass (Lolium perenne L.; PRG) due to its limited cold tolerance and low growth rates at colder temperatures, which can affect subsequent spring herbage dry matter (DM) availability. The effect of PRG ploidy on white clover morphology and growth over winter, and its subsequent recovery in spring and the following growing season, is poorly understood. The objective of this study was to compare the effect of white clover inclusion and PRG ploidy on sward structure, plant morphology and growth of PRG–white clover swards over winter. Four swards (diploid PRG only, tetraploid PRG only, diploid PRG–white clover and tetraploid PRG–white clover) were evaluated over a full winter period (November–February) at a farmlet scale. The PRG ploidy had no effect on herbage DM production, white clover content or tissue turnover (P > 0.05) over winter. However, white clover inclusion caused a significant decrease in herbage DM production (P < 0.001; −254 kg DM/ha) and tiller density (P < 0.001; −1,953 tillers/m2) over winter. Stolon mass was not affected by PRG ploidy (P > 0.05); however, stolon length and number of leaves per stolon were affected by PRG ploidy (P < 0.05). Including white clover in PRG swards can alter winter sward dynamics, potentially causing difficulties in subsequent spring management and performance due to the reduced over-winter growth rate when compared with PRG.

N transfer from white clover to perennial ryegrass, via exudation of nitrogenous compounds

Agronomie ◽  
2003 ◽  
Vol 23 (5-6) ◽  
pp. 503-510 ◽  
Author(s):  
Florence Paynel ◽  
Jean Bernard Cliquet
Keyword(s):  
Perennial Ryegrass ◽  
White Clover ◽  
N Transfer ◽  
Nitrogenous Compounds

USE OF CELL AND MOLECULAR GENETIC MANIPULATION TO IMPROVE PASTURE PLANTS

1988 ◽  
pp. 67-72
Author(s):  
D.W.R. White
Keyword(s):  
Cell Culture ◽  
Perennial Ryegrass ◽  
White Clover ◽  
Nutritional Quality ◽  
Rust Resistance ◽  
Herbicide Tolerance ◽  
Pest Resistance ◽  
Crown Rust ◽  
Wide Range ◽  
Pasture Plants

Cell culture and genetic engineering techniques can be used to develop improved pasture plants. To utilise these methods we have developed procedures for regenerating plants from tissue cultures of perennial ryegrass and white clover. In both, the plant genotype influences regeneration capacity. There was significant genetic variation among regenerated perennial ryegrass plants in a wide range of characteristics. Most of the regenerants were resIstant to crown rust and this trait was highly heritable. This rust resistance is being used to breed a new ryegrass cultivar. A system for introducing cloned genes into white clover is described. This capability is bemg used to incorporate genes with the potential to improve nutritional quality and pest resistance. Other possibilities for engineering genetic improvements in white clover, genes conferring herbicide tolerance and resistance to white clover mosaic virus, are briefly outlined. Keywords: Lolium perenne, Trifolium repens, cell culture, somaclonal variation, crown rust resistance, transformation, cloned genes, nutritional quality, proteinase inhibitors, Bt toxins, pest resistance, WCMV viral cross-protection, herbicide tolerance, Agrobacterium, Bacillus thuringenisis.

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