scholarly journals Variation in the reproductive development of perennial ryegrass (Lolium perenne L.) cultivars

2014 ◽  
Vol 76 ◽  
pp. 189-192 ◽  
Author(s):  
C.M. Wims ◽  
J.M. Lee ◽  
L. Rossi ◽  
D.F. Chapman
Keyword(s):  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Temporal Distribution ◽  
Reproductive Development ◽  
Development Stage ◽  
Early Summer ◽  
Lolium Perenne L ◽  
Flowering Behaviour ◽  
The Mean ◽  
Maturity Groups

Abstract Plant breeding has manipulated the flowering behaviour of perennial ryegrass (Lolium perenne L.) by developing later-heading cultivars. However, the impacts of breeding on the intensity and temporal distribution of flowering are not known. This study compared the reproductive development of 23 perennial ryegrass cultivar/endophyte combinations. In the Waikato and Canterbury, two replicate plots were closed from grazing and tillers were collected every two weeks over a 10-week period during late spring and early summer. Plant development stage was determined for each tiller using a quantitative scale, which was then used to calculate the mean stage count of each cultivar. The rate and timing of reproductive development differed among cultivars. Mid-maturing cultivars matured earlier at both sites compared with late- and very late-maturing cultivars. While the intensity of flowering was similar between maturity groups, the temporal distribution of flowering varied: the late- and very late-maturing cultivars had lower proportions of reproductive tillers early in the season. Keywords: Lolium perenne L., reproductive development, flowering behaviour

The influence of grazing frequency and intensity on the vigour of Lolium perenne L. under subtropical conditions

1996 ◽  
Vol 47 (6) ◽  
pp. 975 ◽  
Author(s):  
FR McKenzie
Keyword(s):  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Grazing Intensity ◽  
Early Summer ◽  
Grazing Management ◽  
Lolium Perenne L ◽  
Continuous Grazing ◽  
Second Year

Lolium perenne L. (perennial ryegrass) exhibits poor persistence in subtropical environments. Grazing management may enhance the vigour and hence persistence of this species. Perennial ryegrass was subjected to various grazing treatments, and its vigour, indexed by etiolated growth, was evaluated over 2 years. Pasture and individual tiller vigour were monitored under 5 combinations of grazing frequency and intensity, applied rotationally, and 1 treatment of continuous grazing. The vigour of infrequently grazed plots was greater than that of frequently or continuously grazed plots; however, grazing intensity did not influence vigour. Seasonally, vigour declined during mid (December and .January) to late (February and March) summer of the establishment year and from early summer (October) to autumn (May) during the second year. Poor vigour in frequently grazed plots was associated with low growth reserves rather than a lack of active tiller growth points. Towards the end of the second year, however, a lack of active tiller growth points also limited vigour in frequently grazed plots. Tillers from infrequently grazed plots (regardless of grazing intensity) had greater vigour than tillers from the frequently grazed plots. To enhance the vigour of perennial ryegrass in subtropical environments, the frequency of grazing should be reduced, particularly in summer.

Tactical versus continuous stocking for persistence of perennial ryegrass (Lolium perenne L.) in pastures grazed by sheep in south-western Victoria

1999 ◽  
Vol 39 (3) ◽  
pp. 265 ◽  
Author(s):  
R. A. Waller ◽  
P. E. Quigley ◽  
G. R. Saul ◽  
G. A. Kearney ◽  
P. W. G. Sale
Keyword(s):  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Seedling Recruitment ◽  
Subterranean Clover ◽  
Trifolium Subterraneum ◽  
Fold Increase ◽  
Early Summer ◽  
Lolium Perenne L ◽  
Western Victoria ◽  
Tiller Density

The survival of perennial ryegrass (Lolium perenne L.) plants was studied in sheep pastures in south-western Victoria during the dry summer of 1996–97. Recruitment of perennial ryegrass seedlings into the pasture sward was also monitored in the autumn–winter periods in 1997 and 1998. The objective was to investigate whether a tactical stocking strategy, consisting of variable length summer, autumn and winter rotations and continuous stocking in spring, might increase perennial ryegrass tiller survival and seedling recruitment in the autumn, compared with continuous stocking all year. The grazing strategies were compared on 2 contrasting pastures: an upgraded pasture [sown with newer cultivars of perennial ryegrass and subterranean clover (Trifolium subterraneum L.) with 26 kg phosphorus/ha.year as applied fertiliser] and a naturalised perennial ryegrass pasture receiving 6 kg P/ha.year. Paddocks were grazed by Border Leicester × Merino ewes, mated to a terminal sire so as to lamb in September. Perennial ryegrass tiller density was higher on the upgraded pasture with a mean density of 7750 tillers/m2 in early summer which declined to zero live tillers by mid summer. Live tillers began to reappear before the opening rains and then increased after the rain. Mean tiller density in the upgraded pasture declined over the 2 summers, with only 2050 tillers/m2 being present 2 months after the opening rains in 1998. There were no effects (P>0.05) of pasture type or grazing strategy on the number of tagged tillers that survived the summer period. Only 12% of the vegetative tillers, randomly tagged in December 1996, survived to May 1997. More than half of the tillers (56%) that produced a seedhead produced daughter tillers which survived the dry summer–autumn period. A significant (P<0.05) interaction between grazing strategy and pasture type occurred with the number of perennial ryegrass seedlings that had established 4 weeks after the opening rains in 1997. There was a 5–11-fold increase in seedling numbers which regenerated in the tactically stocked, upgraded pasture compared with the other treatments. Seedling recruitment was considerably lower in the autumn of 1998, due presumably to an overall decline in perennial ryegrass density relative to annual grasses in 1997. A second experiment investigated the effect of excluding sheep from grazing at anthesis until seedhead maturation or until the opening rains, together with a mechanical seed dislodgment treatment at seed maturity. All exclusion treatments increased seedling recruitment 4–7-fold, compared with continuous stocking. The results suggest a possible mechanism by which perennial ryegrass density can be increased without expensive reseeding.

scholarly journals Modelling factors affecting reproductive development of perennial ryegrass in Waikato dairy pastures

2001 ◽  
pp. 165-170
Author(s):  
C.F. Fiorelli ◽  
S.J.R. Woodward ◽  
M.E. Wastney ◽  
E.R. Thom ◽  
I. Bahmani
Keyword(s):  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Conversion Rate ◽  
Mechanistic Model ◽  
Reproductive Development ◽  
Early Summer ◽  
Biological Processes ◽  
Factors Affecting ◽  
Analyse Data

A mechanistic model was developed to identify biological processes responsible for differences in reproductive tillering between 'Ellett' and 'Grasslands Ruanui' perennial ryegrass cultivars. In the model, a field perennial ryegrass tiller population was represented with six compartments: vegetative, emerging reproductive, mature reproductive and dead tillers (three compartments). The biological processes driving the transfer of tillers from one compartment to another were: conversion of vegetative tillers to reproductive tillers, maturation of emerging reproductive tillers, senescence of mature reproductive tillers, and death of reproductive tillers due to grazing. The model was used to analyse data from Waikato dairy pastures. This enabled some of the effects of irrigation, nitrogen, cultivar and season (weather) on the biological processes to be identified. During spring and early summer, the proportion of reproductive tillers in 'Ellett' pastures was always higher than in 'Grasslands Ruanui', regardless of treatment and year. The model explained this difference by a higher conversion rate of 'Ellett' vegetative tillers to reproductive tillers, and suggested that conversion rate is the key process determining reproductive development in perennial ryegrass. Opportunities to control reproductive tillering are discussed. Keywords: flowering, Lolium perenne, perennial ryegrass, reproductive development

Colchicine-induced heritable modification of chiasma frequency and distribution in perennial ryegrass (Lolium perenne)

Genome ◽  
1995 ◽  
Vol 38 (2) ◽  
pp. 356-361 ◽  
Author(s):  
Lutful Hassan ◽  
R. Neil Jones
Keyword(s):  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Chiasma Frequency ◽  
Mother Cell ◽  
Inbred Lines ◽  
Chromosome Behaviour ◽  
Lolium Perenne L ◽  
Chiasma Distribution ◽  
The Mean ◽  
Heritable Effects

One-week-old seedlings of inbred lines of perennial ryegrass (Lolium perenne L.) were given a 3-h period of treatment with 0.2% colchicine, and this treatment was found to have heritable effects on chromosome behaviour at meiosis. The mean pollen mother cell chiasma frequency was reduced, and there was a corresponding increase in the number of univalents per cell and also changes in cell and bivalent variances. Patterns of chiasma distribution within bivalents were also modified. The effects were seen in the generation in which the treatment was given and they were also observed in the following sexual generation.Key words: chiasmata, colchicine, Lolium perenne, meiosis, perennial ryegrass.

scholarly journals STOLON FORMATION AND SIGNIFICANCE FOR SWARD TILLER DYNAMICS IN PERENNIAL RYEGRASS

1989 ◽  
pp. 255-259 ◽  
Author(s):  
C. Matthew ◽  
S.J. Quilter ◽  
C.J. Korte ◽  
A.C.P. Chu ◽  
A.D. Mackay
Keyword(s):  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Seasonal Cycle ◽  
Early Summer ◽  
Grazing Management ◽  
Lolium Perenne L ◽  
Large Numbers ◽  
Rapid Production ◽  
Tiller Dynamics ◽  
Earthworm Activity

In a pot trial to investigate stolen formation in perennial ryegrass (Lolium perenne L.). 4 genotypes of ryegrass tested all formed stolons. After burial with approximately 30 mm soil in August, cutting and burial, or cutting alone, stolen numbers in November were 18.8 and 3 (SED 3) per plant, respectively. In a grazed ryegrass sward stolen lengths were measured at intervals between May 1987 and April 1988, and for hard and lax grazed plots respectively, were 58 and 96 m/m2 in May, increased to 137 and 164 m/m2 in December, then declined to 47 and 74 ml m2 in April 1998. Active stolon formation in the field began when tillers were buried by earthworm activity and stock trampling in winter. It appears that stolen formation in ryegrass is a response to a seasonal cycle of burial similar to that for white clover. Studies of tagged tillers indicated a pattern of sward renewal in early summer by rapid production of large numbers of tillers from stolons at the base of dying flowering tillers. Other research results suggest that this pattern of sward renewal in perennial ryegrass may be widespread. Implications for grazing management are briefly discussed. Keywords: tiller appearnace rate, perennation, carbohydrate, perennial ryegrass, stolen formation

The use of electrophoretically labelled populations for intra-specific competition studies in perennial ryegrass (Lolium perenne L.) swards

1986 ◽  
Vol 106 (1) ◽  
pp. 99-106 ◽  
Author(s):  
Elsie Quaite ◽  
M. S. Camlin
Keyword(s):  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Dry Matter ◽  
Plant Competition ◽  
Reproductive Development ◽  
Agricultural Practice ◽  
Monthly Basis ◽  
Lolium Perenne L ◽  
June July ◽  
Potential Use

SUMMARYGenotypes homozygous for specific PGI2 alleles were selected from four existing cultivars of different maturities, Gremie, Aberystwyth S.321, Barlenna and Melle. Each of three groups of plants (early BB selected from Gremie, intermediate CC selected from Aberystwyth S.321 and Barlenna and late AA selected from Melle) was isolated and allowed to interpollinate producing three experimental seed lots or populations. These populations, screened for their electrophoretic purity, were found to exhibit only the selected parental PGI2 genotype.The three labelled populations were sown in boxes in September 1982 as monocultures, as all possible 50:50 mixtures, and as a three-way mixture to produce miniswards. Following one harvest in the establishment year these were harvested and dry-matter yields determined on a monthly basis from April to October 1983, two horizons in the sward being examined separately at harvests 1–5. Changes in the proportions of populations in each mixture were monitored by random subsampling of the cut herbage and subsequent electrophoretic testing.The ability to dominate productivity in the top horizon in mixtures was dependent on the timing of reproductive development of any particular population. The patterns of productivity in the bottom horizon and in both horizons combined showed the early population dominating the mixed swards briefly at the beginning of the harvest but the late population dominating from June–July onwards. The intermediate population, although the most productive in monoculture, did not reveal any tendency to dominate productivity in any of the mixtures.The potential use of electrophoretically labelled cultivars to study complex aspects of plant competition is discussed, along with the possible application of results from these studies to agricultural practice.

Incidence of ryegrass endophyte (Neotyphodium lolii) and diversity of associated alkaloid concentrations among naturalised populations of perennial ryegrass (Lolium perenne L.)

2000 ◽  
Vol 51 (5) ◽  
pp. 569 ◽  
Author(s):  
K. F. M. Reed ◽  
A. Leonforte ◽  
P. J. Cunningham ◽  
J. R. Walsh ◽  
D. I. Allen ◽  
...  
Keyword(s):  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Critical Level ◽  
Clinical Symptoms ◽  
Lolium Perenne L ◽  
Grass Endophyte ◽  
Neotyphodium Lolii ◽  
The Mean ◽  
Lolitrem B ◽  
Mutualistic Association

The mutualistic association between perennial ryegrass (Lolium perenne L.) and the ryegrass endophyte Neotyphodium lolii (Latch, Christensen and Samuels) Glenn, Bacon and Hanlin, previously assigned to the genus Acremonium, is known to have a major impact on pasture and animal production. The perennial ryegrass ecotypes Victorian and Kangaroo Valley are the most widely sown varieties of grass in Australian pasture. The incidence of ryegrass endophyte (N. lolii) in these ecotypes, and the production of alkaloids associated with theryegrass endophyte, are largely unexplored. Fifty-six populations of Victorian and 45 of Kangaroo Valley were sampled from old pasture within the recognised zones of naturalisation of both ecotypes. All of the 101 populations examined were infected with ryegrass endophyte. The mean ryegrass endophyte (N. lolii) frequency for plants within the populations of the Victorian and Kangaroo Valley ecotypes was 88% and 93%, respectively. Alkaloid concentrations were determined from infected plants for 39 Kangaroo Valley populations and, in a separate study, for 24 Victorian populations. Ergovaline concentration was above the critical level of 0.4 mg/kg (above which clinical symptoms are observed) for 10% of the Kangaroo Valley populations and 17% of the Victorian populations. For lolitrem B, all Victorian populations were below the critical level of 1.8 mg/kg, but 28% of the Kangaroo Valley populations had mean concentrations above the critical level, 1.8 mg/kg. Concentrations for individual plants were <5 mg/kg for ergovaline, <6 mg/kg for lolitrem B, and <48 mg/kg for peramine. Within each ecotype examined, significant variation (P < 0.05) in the mean concentrations of ergovaline, lolitrem B, and peramine was found between the populations of naturalised perennial ryegrass. Mean concentrations for some of the various naturalised populations were higher than that observed in some of the control cultivars. Low ergovaline and lolitrem B concentrations observed for individual genotypes indicate scope for selecting grass endophyte combinations characterised by optimum production of alkaloids.

Effect of bacterial fertilizers on the properties of a pseudomyceliar chernozem soil and on the biomass of perennial ryegrass (Lolium perenne L.)

2011 ◽  
Vol 60 (1) ◽  
pp. 219-232 ◽  
Author(s):  
Anita Jakab ◽  
János Kátai ◽  
Magdolna Tállai ◽  
Andrea Balláné Kovács
Keyword(s):  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Chernozem Soil ◽  
Lolium Perenne L

A tenyészedényes kísérletünket a DE AGTC MÉK Agrokémiai és Talajtani Intézet tenyészházában állítottuk be 2010. május 27-én. A kísérletben Debrecen-Látókép környékéről származó mészlepedékes csernozjom vályogtalajt alkalmaztunk, amely az alábbi jellemzőkkel rendelkezett: KA: 37,5; leiszapolható rész: 51%; pH(KCl): 5,5; pH(H2O): 6,6; Hu%: 2,8; AL-P2O5: 140 mg·kg-1; AL-K2O: 316,3 mg·kg-1. Az adatok alapján a kísérleti talaj gyengén savanyú, vályog kötöttségű, közepes nitrogén- és foszfor-, valamint jó kálium-ellátottsággal rendelkezett. A kísérletben kontroll-, műtrágya-, valamint szalmakezelést alkalmaztunk, melyeket bizonyos kombinációkban három különböző baktériumkészítménnyel (Bactofil A, EM-1, Microbion UNC) egészítettünk ki. A kísérletet három ismétlésben véletlenblokk elrendezésben állítottuk be. A tesztnövény angolperje (Lolium perenneL.) volt. A kísérlet kezdetétől számított 8. héten a talaj-, valamint a növényminták begyűjtésére került sor. Meghatároztuk a növényminták száraztömegét, a növény foszfor- és káliumtartalmát, valamint a talajminták nitrát-, valamint AL-oldható foszfor- és káliumtartalmát. Eredményeink alapján főbb megállapításaink a következők: – Az angolperje száraztömegét a műtrágyakezelés szignifikánsan növelte. A hatás a tápelem-ellátottság javulásával magyarázható. – A növény foszforkoncentrációja a műtrágyázás következtében csökkent, amelyet a hígulási effektussal magyarázhatunk. – A növény káliumkoncentrációját a műtrágya-, valamint a műtrágya+baktériumtrágya kezelések szignifikánsan serkentették. – A talaj nitráttartalma szignifikánsan növekedett a műtrágyakezelés kivételével minden kezelésben. – A talaj AL-P2O5-tartalma az NPK-műtrágyázás és az EM-1 kezelés következtében statisztikailag igazolható mértékben megnövekedett, míg az AL-K2O-tartalom kizárólag a szalmakezelés hatására nőtt. A baktériumkészítmények önmagukban alkalmazva általában nem eredményeztek jelentős változást a vizsgált paraméterekben, azonban a készítmények szerves/ásványi anyagokkal kombinált adagolása esetében különböző mértékben befolyásolták a vizsgált mutatókat.

The effect of biological additives on the composition and nutritive value of silage

1990 ◽  
Vol 1990 ◽  
pp. 139-139
Author(s):  
M Gonzalez Yanez ◽  
R Mcginn ◽  
D H Anderson ◽  
A R Henderson ◽  
P Phillips
Keyword(s):  
Cell Wall ◽  
Lactic Acid ◽  
Lactic Acid Bacteria ◽  
Lolium Perenne ◽  
Perennial Ryegrass ◽  
Nutritive Value ◽  
Enzyme System ◽  
Lolium Perenne L ◽  
Grass Silage ◽  
Forage Harvester

It Is claimed that the use of the correct enzyme system as an additive on grass silage will satisfactorily control the fermentation and reduce the cell-wall fibre content, thus preserving the nutrients In the silage and aiding their utilisation by the animal (Henderson and McDonald, 1977; Huhtanen et al, 1985; Raurama et al, 1987; Chamberlain and Robertson, 1989; Gordon, 1989;).The aim of the present experiment was to assess the effect of biological additives, enzymes or a combination of enzymes with an Inoculum of lactic acid bacteria, on the composition of silage and on its nutritive value when offered to store lambs as the sole constituent of their diet.On 1st June 1988, first cut perennial ryegrass (Lolium perenne L) at pre-ear emergence was ensiled direct cut untreated (U), treated with a commercial enzyme (E) or with a commercial inoculum of lactic acid bacteria with enzymes (I) in 6t capacity bunker silos. The grass was cut with a mower and lifted with a New Holland precision chop forage harvester. The additives were pumped onto the grass using a dribble bar sited over the pick-up drum.

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