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

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.

2014 ◽  
Vol 76 ◽  
pp. 189-192 ◽  
Author(s):  
C.M. Wims ◽  
J.M. Lee ◽  
L. Rossi ◽  
D.F. Chapman

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


2000 ◽  
Vol 51 (5) ◽  
pp. 569 ◽  
Author(s):  
K. F. M. Reed ◽  
A. Leonforte ◽  
P. J. Cunningham ◽  
J. R. Walsh ◽  
D. I. Allen ◽  
...  

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.


2011 ◽  
Vol 60 (1) ◽  
pp. 219-232 ◽  
Author(s):  
Anita Jakab ◽  
János Kátai ◽  
Magdolna Tállai ◽  
Andrea Balláné Kovács

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.


Author(s):  
M Gonzalez Yanez ◽  
R Mcginn ◽  
D H Anderson ◽  
A R Henderson ◽  
P Phillips

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.


Crop Science ◽  
2001 ◽  
Vol 41 (5) ◽  
pp. 1565-1572 ◽  
Author(s):  
Christine Kubik ◽  
Mark Sawkins ◽  
William A. Meyer ◽  
Brandon S. Gaut

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