scholarly journals A new genetic locus for self-compatibility in the outcrossing grass species perennial ryegrass (Lolium perenne)

2020 ◽  
Author(s):  
Lucy M Slatter ◽  
Susanne Barth ◽  
Chloe Manzanares ◽  
Janaki Velmurugan ◽  
Iain Place ◽  
...  
Keyword(s):  
Perennial Ryegrass ◽  
Genetic Locus ◽  
Physiological Mechanism ◽  
Snp Markers ◽  
Evolutionary Significance ◽  
Grass Species ◽  
Complex Nature ◽  
Self Fertilization ◽  
Self Compatibility

Abstract Background Self-incompatibility (SI) is a physiological mechanism that many flowering plants employ to prevent self-fertilization and maintain heterozygosity. In the grass family this is known to be controlled by a two locus (S-Z) system; however, the SI system is intrinsically leaky. Modifier genes of both the S and Z loci and a further locus, T, are known to override SI leading to self-fertilization and self-seed production. This has implications for the ecological and evolutionary success as well as the commercial breeding of grasses. Here we report a study where the genetic control of self-compatibility (SC) was determined from the results of self-pollinating an F2 population of perennial ryegrass from two independently derived inbred lines produced by single-seed descent. Methods In vitro self-pollinations of 73 fertile plants were analysed. A genetic association analysis was made with a panel of 1863 single-nucleotide polymorphism (SNP) markers, generated through genotype-by-sequencing methodology. Markers were placed on a recombination map of seven linkage groups (LGs) created using Joinmap v.5. The seed set on self- and open-pollinated inflorescences was determined on 143 plants, including the 73 plants analysed for self-pollination response. Key Results Self-pollinations revealed a bimodal distribution of percentage SC with peaks at 50 and 100 %. A single quantitative trait locus (QTL) was identified with peak association for marker 6S14665z17875_11873 that mapped to LG 6. Peak position was associated with maximum marker segregation distortion. The self-compatible plants were equally fecund after self- and open pollination. Conclusions This is the first report in the Poaceae family of an SC locus located on LG 6. This new SC QTL discovery, as well as indicating the complex nature of the pollen–stigma recognition process and its evolutionary significance, provides an additional source of SC for breeding perennial ryegrass.

The effects of method of processing on the intake and digestibility by lambs of dried perennial rye-grass and tall fescue

1974 ◽  
Vol 19 (2) ◽  
pp. 193-200 ◽  
Author(s):  
R. M. Tetlow ◽  
R. J. Wilkins
Keyword(s):  
Particle Size ◽  
Organic Matter ◽  
Weight Gain ◽  
Perennial Ryegrass ◽  
Tall Fescue ◽  
Live Weight ◽  
Grass Species ◽  
Live Weight Gain

SUMMARYCobs and pellets which differed in particle size (modulus of fineness, MF) were prepared from dried perennial ryegrass and tall fescue and given to sheep. The MF values of the feeds were 2·45,1·09,0·81 and 0·74 for perennial ryegrass and 2·28,0·84,0·67 and 0·57 for tall fescue. Organic matter digestibility was similar for the two grass species when measured in vivo, but when measured in vitro values for perennial ryegrass were about 3 units higher than those for tall fescue. Voluntary intake and live-weight gain were higher for sheep given tall fescue, the difference in live-weight gain being just significant at P < 0·05. The response to change in particle size was similar for the two grass species. Intake was lowest and digestibility highest for the feeds with the highest MF, but differences between the three finely-ground forms of each species were not significant. There was a tendency for the intake of digestible organic matter to be lower for the feeds with lowest MF than for those with intermediate values for MF. The rate of passage of undigested particles was slower for cobs with the highest MF than for the other feeds, which did not differ significantly one from another.

In vitro rumen methane output of perennial ryegrass varieties and perennial grass species harvested throughout the growing season

2012 ◽  
Vol 67 (2) ◽  
pp. 280-298 ◽  
Author(s):  
P. J. Purcell ◽  
M. O’Brien ◽  
A. Navarro-Villa ◽  
T. M. Boland ◽  
M. McEvoy ◽  
...  
Keyword(s):  
Perennial Ryegrass ◽  
Perennial Grass ◽  
Growing Season ◽  
Grass Species

Responses to the renovation of an irrigated perennial pasture in northern Victoria. 1. Pasture consumption and nutritive characteristics

2007 ◽  
Vol 47 (2) ◽  
pp. 149 ◽  
Author(s):  
A. R. Lawson ◽  
K. B. Kelly
Keyword(s):  
Dairy Cows ◽  
Perennial Ryegrass ◽  
Tall Fescue ◽  
Crude Protein ◽  
Italian Ryegrass ◽  
Grass Species ◽  
Spring Period ◽  
Summer Pasture ◽  
The Cost

A field experiment was established in northern Victoria in the autumn of 1999 to quantify the effects of renovating a 15-year-old irrigated perennial pasture which had a high paspalum content [>40% dry matter (DM)] in summer. The treatments were: (i) control, the existing pasture; (ii) oversown, in which the existing pasture was grazed, topped and direct drilled; and (iii) resown, in which the existing pasture was sprayed, cultivated and sown with a new pasture. The grass species used in both renovation treatments were perennial ryegrass, Italian ryegrass and tall fescue. The treatments were grazed by dairy cows when the perennial ryegrass had reached the 2.5–3 leaf stage. Grazing of the resown tall fescue coincided with the resown ryegrass in years 1 and 2, but in subsequent years, resown tall fescue was grazed at a rising plate meter height of 80 mm. All treatments were grazed to a residual pasture height of 40–45 mm, as measured with a rising plate meter. Pasture consumption (measured as DM removed by dairy cows), in vitro DM digestibility (in vitro DMD) and crude protein (CP) contents were measured. Oversowing increased pasture consumption over the 4-year period, compared with the control, by an average of 1.1 t DM/ha.year when oversown once with perennial ryegrass and by 1.6 t DM/ha.year when oversown annually with Italian ryegrass. This increase occurred principally during the winter–spring period for pastures oversown with both perennial (0.7 t DM/ha) and Italian (1.6 t DM/ha) ryegrass. Oversowing with perennial or Italian ryegrass did not affect the in vitro DMD or CP content of the pasture on offer. These results show that oversowing with either perennial or Italian ryegrass is a viable means of increasing pasture availability over winter and spring from perennial pastures consisting of a mixture of perennial ryegrass, white clover and paspalum. Pasture consumption in the first 12 months after resowing was 3.5–4.1 t DM/ha lower from the resown than from the control pasture. This was because of two fewer grazings in autumn–winter and to reductions in pasture consumption of 20% in spring and of 40% in summer. These reductions would add considerably to the cost of resowing through increasing the need for supplementary feeding. Pasture consumption from the resown perennial ryegrass pasture in years 2–4 was, on average, the same as the control, although it was higher during winter and spring and lower during summer. Pasture consumption from the resown tall fescue pasture in years 2–4 was, on average, 2.5 t DM/ha.year higher than that of the resown perennial ryegrass pasture, with most of this increase occurring in summer and autumn. The resown pastures had higher in vitro DMD and CP contents than the control with little difference between the resown perennial ryegrass and tall fescue pastures. These findings show that tall fescue is a viable alternative to perennial ryegrass when resowing pastures. The use of nitrogen fertiliser did not affect the in vitro DMD or CP contents of the pasture on offer but allowed an increase in DM consumption, with this increase being greater for the control and oversown pastures than for the resown pasture.

scholarly journals Transcriptomics differentiate two novel bioactive strains of Paenibacillus sp. isolated from the perennial ryegrass seed microbiome

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Tongda Li ◽  
Ross Mann ◽  
Jatinder Kaur ◽  
German Spangenberg ◽  
Timothy Sawbridge
Keyword(s):  
Nitrogen Fixation ◽  
Secondary Metabolite ◽  
Perennial Ryegrass ◽  
Fusarium Verticillioides ◽  
In Vitro Assays ◽  
Colletotrichum Graminicola ◽  
Nitrogen Fixation Activity ◽  
Auxin Production ◽  
Paenibacillus Sp

AbstractPaenibacillus species are Gram-positive bacteria that have been isolated from a diverse array of plant species and soils, with some species exhibiting plant growth-promoting (PGP) activities. Here we report two strains (S02 and S25) of a novel Paenibacillus sp. that were isolated from perennial ryegrass (Lolium perenne) seeds. Comparative genomics analyses showed this novel species was closely related to P. polymyxa. Genomic analyses revealed that strains S02 and S25 possess PGP genes associated with biological nitrogen fixation, phosphate solubilisation and assimilation, as well as auxin production and transportation. Moreover, secondary metabolite gene cluster analyses identified 13 clusters that are shared by both strains and three clusters unique to S25. In vitro assays demonstrated strong bioprotection activity against phytopathogens (Colletotrichum graminicola and Fusarium verticillioides), particularly for strain S02. A transcriptomics analysis evaluating nitrogen fixation activity showed both strains carry an expressed nif operon, but strain S02 was more active than strain S25 in nitrogen-free media. Another transcriptomics analysis evaluating the interaction of strains with F. verticillioides showed strain S02 had increased expression of core genes of secondary metabolite clusters (fusaricidin, paenilan, tridecaptin and polymyxin) when F. verticillioides was present and absent, compared to S25. Such bioactivities make strain S02 a promising candidate to be developed as a combined biofertiliser/bioprotectant.

scholarly journals Reference transcriptome assembly and annotation for perennial ryegrass

Genome ◽  
2017 ◽  
Vol 60 (12) ◽  
pp. 1086-1088 ◽  
Author(s):  
Hiroshi Shinozuka ◽  
Noel O.I. Cogan ◽  
German C. Spangenberg ◽  
John W. Forster
Keyword(s):  
Perennial Ryegrass ◽  
Transcriptome Assembly ◽  
Genotyping By Sequencing ◽  
Whole Genome Sequence ◽  
Grass Species ◽  
Rna Seq ◽  
Pasture Grass ◽  
Tissue Samples ◽  
Genome Sequence Assembly ◽  
Transcriptome Resource

RNA-Seq methodology has been used to generate a comprehensive transcriptome sequence resource for perennial ryegrass, an important temperate pasture grass species. A total of 931 547 255 reads were obtained from libraries corresponding to 19 distinct tissue samples, including both vegetative and reproductive stages of development. Assembly of data generated a final filtered reference set of 48 713 contigs and scaffolds. The transcriptome resource will support whole genome sequence assembly, comparative genomics, implementation of genotyping-by-sequencing (GBS) methods based on transcript sampling, and identification of candidate genes for multiple biological functions.

The effect of species complexity and sodium fertilizer application on the grazing behaviour of calves

1993 ◽  
Vol 1993 ◽  
pp. 142-142
Author(s):  
M. Youssef ◽  
P.C. Chiy ◽  
C.J.C. Phillips ◽  
M. Metwally
Keyword(s):  
Perennial Ryegrass ◽  
Fertilizer Application ◽  
Grass Species ◽  
Individual Plant ◽  
Adult Cattle ◽  
High Sodium ◽  
Red Fescue ◽  
Stages Of Growth ◽  
High Sodium Diet ◽  
Grazing Behaviour

Cattle exhibit preferences not only for certain sward species but for the same species at different stages of growth, and the various parts of an individual plant and for individual plant of preferred composition. This tendency is termed selective grazing (Fontenot and Blaser, 1965). For example ruminants will select a high Sodium diet. Calves tend to be more selective than adult cattle, muzzling herbage before eating.The aim of the present experiment was to investigate the effect of sward complexity, species and sodium fertilizer on the grazing behaviour of calves.Sixteen dairy Friesian calves, aged 5 to 6 months, with no previous grazing experience, were allocated to groups of 4 similar calves, and then at random to four pasture treatments of 3480m2 each with one (Perennial Ryegrass, P), two (P and Timothy, T), three (P, T and Cocksfoot, C) and four (P, T.C and Red Fescue, R) grass species in a balanced change over design. Each species was sown in plots of 290m2 and one half of each plot received 48Kg/ha. nacl.

Effects of feeding ryegrass of varying maturity on the metabolism and composition of lipids in the rumen of sheep

1986 ◽  
Vol 106 (3) ◽  
pp. 445-448 ◽  
Author(s):  
T. Gerson ◽  
A. John ◽  
A. S. D. King
Keyword(s):  
Fatty Acid ◽  
Lipid Metabolism ◽  
Linoleic Acid ◽  
Blood Plasma ◽  
Polyunsaturated Fatty Acid ◽  
Perennial Ryegrass ◽  
Crude Protein ◽  
Linseed Oil ◽  
Triacyl Glycerol

SummaryTwo experiments were carried out to test the effects of ryegrass maturity on rumen lipid metabolism. In the first experiment the effect of stage of maturity of perennial ryegrass on lipid metabolism in the rumen was studied with grazing sheep fitted with rumen cannulae. The pasture was either immature (13·8% crude protein), mature (8·1% crude protein) or senescent (5·5% crude protein).The ratesin vitroof triacyl glycerol lipolysis and linoleic acid (18: 2w6) hydrogenation were found to decrease with increasing age of the ryegrass.In the second experiment the sheep were dosed with emulsified linseed oil (30 g) via rumen cannulae while grazing immature or senescent ryegrass and the rumen digesta and blood plasma sampled at 0, 4 and 8 h after dosing.The proportions of linseed oil retained in the rumen were greater and blood plasma linoleic (18:2w6) and linolenic (18:3w3) acid concentrations higher when senescent ryegrass was fed.It was concluded that the rates of rumen lipolysis and hydrogenation decreased with the age of pasture and that after dosing with linseed oil the polyunsaturated fatty acid concentrations in blood plasma increased.

scholarly journals Genetic Transformation of Apomictic Grasses: Progress and Constraints

2021 ◽  
Vol 12 ◽  
Author(s):  
Andrés M. Bellido ◽  
Eduado D. Souza Canadá ◽  
Hugo R. Permingeat ◽  
Viviana Echenique
Keyword(s):  
Genetic Transformation ◽  
Plant Transformation ◽  
Large Scale ◽  
Crop Improvement ◽  
Current Status ◽  
Grass Species ◽  
Brachiaria Brizantha ◽  
Apomictic Species ◽  
Transformation Methods

The available methods for plant transformation and expansion beyond its limits remain especially critical for crop improvement. For grass species, this is even more critical, mainly due to drawbacks in in vitro regeneration. Despite the existence of many protocols in grasses to achieve genetic transformation through Agrobacterium or biolistic gene delivery, their efficiencies are genotype-dependent and still very low due to the recalcitrance of these species to in vitro regeneration. Many plant transformation facilities for cereals and other important crops may be found around the world in universities and enterprises, but this is not the case for apomictic species, many of which are C4 grasses. Moreover, apomixis (asexual reproduction by seeds) represents an additional constraint for breeding. However, the transformation of an apomictic clone is an attractive strategy, as the transgene is immediately fixed in a highly adapted genetic background, capable of large-scale clonal propagation. With the exception of some species like Brachiaria brizantha which is planted in approximately 100 M ha in Brazil, apomixis is almost non-present in economically important crops. However, as it is sometimes present in their wild relatives, the main goal is to transfer this trait to crops to fix heterosis. Until now this has been a difficult task, mainly because many aspects of apomixis are unknown. Over the last few years, many candidate genes have been identified and attempts have been made to characterize them functionally in Arabidopsis and rice. However, functional analysis in true apomictic species lags far behind, mainly due to the complexity of its genomes, of the trait itself, and the lack of efficient genetic transformation protocols. In this study, we review the current status of the in vitro culture and genetic transformation methods focusing on apomictic grasses, and the prospects for the application of new tools assayed in other related species, with two aims: to pave the way for discovering the molecular pathways involved in apomixis and to develop new capacities for breeding purposes because many of these grasses are important forage or biofuel resources.

scholarly journals The effect of dairyshed effluent irrigation on the occurrence of plant pathogenic Pythium species in pasture

2000 ◽  
Vol 53 ◽  
pp. 436-440 ◽  
Author(s):  
N.W. Waipara ◽  
S.K. Hawkins
Keyword(s):  
Perennial Ryegrass ◽  
White Clover ◽  
Subterranean Clover ◽  
Preliminary Survey ◽  
Pythium Species ◽  
Effluent Irrigation ◽  
Pathogenicity Tests ◽  
Roots In Vitro

A preliminary survey of pastures sprayirrigated with dairyshed effluent revealed a significant increase in the population of plant pathogenic Pythium species isolated from both soil and roots In vitro pathogenicity tests showed the majority of these isolates to be pathogenic when inoculated onto the seedlings of white clover subterranean clover and perennial ryegrass although both clover species were more susceptible to Pythiuminduced disease than ryegrass

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