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At least 19 recordsLinked to original sources

PubMed2002

Rathayibacter caricis sp. nov. and Rathayibacter festucae sp. nov., isolated from the phyllosphere of Carex sp. and the leaf gall induced by the nematode Anguina graminis on Festuca rubra L., respectively.

Two novel species, Rathayibacter caricis sp. nov. (type strain VKM Ac-1799T = UCM Ac-618T) and Rathayibacter festucae sp. nov. (type strain VKM Ac-1390T UCM Ac-619T), are proposed for two coryneform actinomycetes found in the phyllosphere of Carex sp. and in the leaf gall induced by the plant-parasitic nematode Anguina graminis on Festuca rubra L., respectively. The strains of the novel species are typical of the genus Rathayibacter in their chemotaxonomic characteristics and fall into the Rathayibacter 16S rDNA phylogenetic cluster. They belong to two separate genomic species and differ markedly from current validly described species of Rathayibacter at the phenotypic level. The most striking feature differentiating Rathayibacter caricis sp. nov. from other species of the genus is the presence of fucose in its cell wall and Rathayibacter festucae sp. nov. can be easily recognized among other yellow-pigmented rathayibacters because of its rose-orange-coloured colonies.

Actinomycetales↗

PubMed2001

Epichloë festucae and related mutualistic symbionts of grasses.

Epichloë and Neotyphodium species (Ascomycota) are mutualistic symbionts (endophytes) of temperate grasses, to which they impart numerous and profound fitness benefits. Epichloë festucae, a common symbiont of Festuca, Lolium,and Koeleria spp., is a model for endophyte research that is amenable to Mendelian and molecular genetic analysis. Characteristics of E. festucae include: (i) production of the anti-insect alkaloids peramine and lolines, (ii) production of the anti-vertebrate alkaloids lolitrem B and ergovaline, (iii) efficient vertical transmission via host seeds, (iv) a mildly pathogenic state associated with the E. festucae sexual cycle, and (v) a clear role in enhancing survival of host plants. Genetic analysis of alkaloid production has recently begun. Also, physiological and ultrastructural studies suggest that signals communicated between E. festucae and host plants ensure an exquisitely balanced interaction to the mutual benefit of both partners. Several mutualistic Neotyphodium species are hybrids between E. festucae and other endophyte species.

Animals↗

PubMed2001

Androgenesis from Festuca pratensis x Lolium multiflorum amphidiploid cultivars in order to select and stabilize rare gene combinations for grass breeding.

Androgenesis using amphidiploid cultivars of Festuca pratensis x Lolium multiflorum as parents, overcame earlier problems that gave rise to widespread plant sterility amongst androgenic Festulolium populations. Two Festuca pratensis x Lolium multiflorum (2n = 4x = 28) cultivars, Sulino and Felopa, were highly amenable to androgenesis and 10% of plants, including some novel androgenic genotypes, had sufficient fertility to produce progeny and further generations. The genomes of amphidiploid cultivars, which represent the F8 generation, were the result of considerable intergeneric chromosome recombination. Moreover, during cultivar development, natural and breeders' selection pressures had led to the assembly of gene combinations that conferred good growth characters and fertility with the removal of putative deleterious gene combinations. Over 80% of the androgenic plants derived from the amphidiploid F. pratensis x L. multiflorum (2n = 4x = 28) had 14 chromosomes and were likely to be dihaploids with a single genome of Lolium and of Festuca. In contrast, hybrids of F. pratensis x L. multiflorum (2n = 2x = 14) found naturally are invariably sterile. Structural reorganization within the genomes of the androgenic Festulolium plants had restored fertility in genotypes expected to contain the haploid genome of Lolium and Festuca. This provided opportunities for their future incorporation in breeding programmes and the development of fertile diploid Lolium-Festuca hybrids. Amongst the androgenic plants, Festulolium genotypes were recovered that conferred excellent drought resistance or freezing tolerance and were thought to be highly suitable for entry into plant breeding programmes.

Adaptation, Physiological↗

PubMed2002

Agrobacterium tumefaciens-mediated transformation of Festuca arundinacea (Schreb.) and Lolium multiflorum (Lam.).

Agrobacterium tumefaciens strain LBA4404 carrying plasmid pTOK233 encoding the hygromycin resistance (hph) and beta-glucuronidase (uidA) genes has been used to transform two agronomic grass species: tall fescue (Festuca arundinacea) and Italian ryegrass (Lolium multiflorum). Embryogenic cell suspension colonies or young embryogenic calli were co-cultured with Agrobacterium in the presence of acetosyringone. Colonies were grown under hygromycin selection with cefotaxime and surviving colonies plated on embryogenesis media. Eight Lolium (six independent lines) and two Festuca plants (independent lines) were regenerated and established in soil. All plants were hygromycin-resistant, but histochemical determination of GUS activity showed that only one Festuca plant and one Lolium plant expressed GUS. Three GUS-negative transgenic L. multiflorum and the two F. arundinacea plants were vernalised and allowed to flower. All three Lolium plants were male- and female-fertile, but the Festuca plants failed to produce seed. Progeny analysis of L. multiflorum showed a 24-68% inheritance of the hph and uidA genes in the three lines with no significant difference between paternal and maternal gene transmission. However, significant differences were noted between the paternal and maternal expression of hygromycin resistance.

Agrobacterium tumefaciens↗

PubMed2002

Application of GISH and AFLP techniques for identification of Lolium-Festuca introgressions.

At present, breeding programmes aimed at combining advantageous traits within the Lolium-Festuca complex, are mainly focused on introgression procedures. One principal objective, is the transfer of genes conferring resistance to abiotic stresses from Festuca species (F. pratensis, F. arundinacea and F. glaucescens) into Lolium multiflorum and L. perenne germplasm. In our experiments, two different hybrids: triploid - L. multiflorum (4x) x F. pratensis (2x) and pentaploid - F. arundinacea (6x) x L. multiflorum (4x) were backcrossed twice onto L. multiflorum cultivars, and numerous BC2 progeny generated. BC2 plants from both combinations were tested in field and/or simulated conditions for winter hardiness and drought resistance. GISH (genomic in situ hybridisation) analyses were then performed on the most winter hardy and drought resistant plants to locate putative genes for stress resistance. Using resistant L. multiflorum genotypes with a single Festuca chromatin segment, it was possible to allocate AFLP (amplified fragment length polymorphism) markers specific to that segment. Markers associated with genes conferring stress resistance facilitate marker-assisted selection programmes to obtain new, more persistent grass cultivars. Preliminary results of GISH analysis, to identify Festuca chromosome segments in L. multiflorum introgression lines and to find segment-specific AFLP markers, are presented

Breeding↗

PubMed2002

Genetic structure of natural populations of the grass endophyte Epichloë festucae in semiarid grasslands.

Plants of red fescue (Festuca rubra), a commercially important turf grass, are infected by the fungal endophyte Epichloë festucae in semiarid natural grasslands, known as dehesas, in western Spain. We used amplified fragment length polymorphism (AFLP) markers to analyse the genetic polymorphism existing in two natural populations of Epichloë festucae. Linkage disequilibrium and the presence of clonal lineages indicated that nonrecombinant asexual reproduction predominates in both populations. However, most genetic variation detected was found to occur within populations, with only a moderate amount of genetic differentiation between populations (F(ST): 0.197). Overall, the study suggests that dehesa grasslands are useful reservoirs of Epichloë festucae endophytes, and provides information on population structure which is relevant to design sampling strategies.

Genetic Variation↗

PubMed2000

Genomic in situ hybridization (GISH) reveals high chromosome pairing affinity between Lolium perenne and Festuca mairei.

Intergeneric hybridizations have been made between species of Lolium and Festuca. It has been demonstrated, largely through conventional cytogenetic analysis, that the genomes of the two genera are related, however, much information is lacking on exactly how closely related the genomes are between the two species. We applied genomic in situ hybridization (GISH) techniques to the F1 hybrids of tetraploid Festuca mairei with a genomic constitution of M1M1M2M2 and diploid Lolium perenne with a genomic constitution of LL. It was shown in the triploid hybrids (LM1M2) that the chromosomes of M1 and M2 from F. mairei could pair with each other, and it was further discovered that L chromosomes of L. perenne paired with M1 and M2 chromosomes. Our results showed that meiocytes of Lolium-Festuca are amenable to GISH analysis, and provided direct evidence for the hypothesis that the chromosomes of Lolium and Festuca may be genetically equivalent and that reciprocal mixing of the genomes may be possible.

Evolution, Molecular↗

PubMed2000

Isolation and characterization of fungal inhibitors from Epichloë festucae.

A series of studies was conducted to test the antifungal activity of clavicipitaceous endophytes and to identify potential fungal inhibitors in this symbiotic infection. A diverse group of endophytes was screened for antifungal activity using organic extracts from liquid fermentation cultures. Fungal inhibitors were purified from fermentation cultures of Epichloë festucae using a bioassay-directed extraction with Cryphonectria parasitica as the test organism. Compounds shown to have antifungal activity were subsequently identified using NMR and GC-MS. Extracts from a wide range of fungal isolates had various degrees of antifungal activity, but the greatest antifungal activity was observed in E. festucae and Neotyphodium tembladerae. Three types of inhibitors were isolated from a batch culture of E. festucae, including several indole derivatives, a sesquiterpene, and a diacetamide. Among the indole derivatives, indole-3-acetic acid and indole-3-ethanol were identified as the major indoles. These compounds were previously reported in endophytic fungi, and this study suggests a role in host disease resistance against other pathogens. The diversity in fungal inhibitors produced by this endophyte also suggests that fungal inhibitors may act additively or synergistically to reduce colonization of endophyte-infected hosts by potential fungal competitors.

Antifungal Agents↗

PubMed1996

Susceptibilities of Different Test Systems from Maize (Zea mays), Poa annua, and Festuca rubra to Herbicides That Inhibit the Enzyme Acetyl-Coenzyme A Carboxylase

The susceptibilities of maize (Zea mays cv. Champ) and two graminicide-resistant grass species, Poa annua (annual meadow grass) and Festuca rubra (red fescue), to two aryloxyphenoxypropionates (quizalofop and fluazifop) and a cyclohexanedione (sethoxydim) graminicide were evaluated in leaf blades and isolated chloroplasts, and by assaying acetyl-coenzyme A carboxylase (ACCase) in desalted leaf homogenates. The graminicide resistance of P. annua and F. rubra appeared to be at the level of ACCase. Festuca rubra ACCase was highly insensitive and P. annua ACCase was partially insensitive to the graminicides that were tested. Fatty acid synthesis in isolated maize chloroplasts was more susceptible to inhibition than was ACCase activity from whole leaves. There was a smaller difference in graminicide sensitivity between these two test systems in P. annua. The developmental pattern of ACCase specific activity and its inhibition by quizalofop was measured in maize and P. annua leaf blades. There was an age-dependent increase in the sensitivity of maize leaf ACCase activity to inhibition by quizalofop. Together with the greater susceptibility of chloroplasts compared with leaf homogenates this could imply that a graminicide-insensitive (extrachloroplastic) ACCase isoform is less highly expressed in older leaves. Poa annua ACCase did not significantly alter in sensitivity as leaves aged, consistent with the smaller difference in the level of inhibition between chloroplasts and leaf homogenates in this species. A small pyruvate carboxylase activity was detected in maize leaves after 9 days. By 38 days, when leaves were senescing, pyruvate carboxylase activity predominated over ACCase.

Journal Article↗

PubMed2001

Molecules and morphology in concert. II. The Festuca brachyphylla complex (Poaceae) in Svalbard.

We used a combined molecular and morphological approach to unravel variation in the autogamous Festuca brachyphylla polyploid complex in the arctic archipelago of Svalbard. Forty populations were analyzed for random amplified polymorphic DNAs (RAPDs) and 46 morphological characters. Eighteen RAPD multilocus phenotypes were observed in the 86 plants analyzed, based on 30 polymorphic markers. Multivariate analyses of the RAPD data revealed four distinct groups of multilocus phenotypes; in contrast, the variation was more or less continuous in multivariate analyses of the morphological data. However, we identified several individual morphological characters that unambiguously discriminated among the four groups of RAPD multilocus phenotypes. Analysis of type material suggests that the four groups in Svalbard can be referred to Festuca baffinensis, F. brachyphylla, F. hyperborea, and F. edlundiae. This study shows that concerted analysis of molecules and morphology is a powerful tool in low-level taxonomy.

Journal Article↗

PubMed2002

[Quantitative characteristics of degenerative succession in Festuca sinensis sowing grassland in the alpine pastoral area].

Quantitative characteristics of degenerative succession in Festuca sinensis sowing grassland in the alpine pastoral area were studied. The results showed that with the succession developing, number of species, richness index, diversity index, and evenness index were all increased, but ecological dominance was decreased. Analysis on important values, niche width, and niche overlaps proved that some herb species such as Ajania tenuifolia and Polygomum sibiricum were pioneer plants invading sowing grassland in the succession process. The pioneer plants had wider niche widths than other species, and their important values increased with the succession developing. Niche overlaps between Festuca sinensis and other species were smaller than that between two latifoliate herbs species in most case. The invasion of latifoliate herbs was one of the most important factors, which made the sowing grassland more degenerative.

Cold Climate↗

PubMed2003

Field performance of transgenic tall fescue (Festuca arundinacea Schreb.) plants and their progenies.

Tall fescue (Festuca arundinacea Schreb.) is a hexaploid, outcrossing grass species widely used for forage and turf purposes. Transgenic tall fescue plants were generated by biolistic transformation of embryogenic cell suspension cultures that were derived from single genotypes of widely used cultivar Kentucky-31. Primary transgenics from two genotypes, their corresponding regenerants from the same genotypes and control seed-derived plants were transferred to the field and evaluated for 2 years. Progenies of these three classes of plants were obtained and evaluated together with seed-derived plants in a second field experiment. The agronomic characteristics evaluated were: heading date, anthesis date, height, growth habit, number of reproductive tillers, seed yield and biomass. The agronomic performance of the primary transgenics and regenerants was generally inferior to that of the seed-derived plants, with primary transgenics having fewer tillers and a lower seed yield. However, no major differences between the progenies of transgenics and the progenies of seed-derived plants were found for the agronomic traits evaluated. Primary transgenics and regenerants from the same genotype were more uniform than plants from seeds. Progenies of transgenics performed similarly to progenies of the regenerants. The addition of a selectable marker gene in the plant genome seems to have had little effect on the agronomic performance of the regenerated plants. No indication of weediness of the transgenic tall fescue plants was observed. Our results indicate that outcrossing grass plants generated through transgenic approaches can be incorporated into forage breeding programs.

Biolistics↗

PubMed2003

A linkage map of meadow fescue ( Festuca pratensis Huds.) and comparative mapping with other Poaceae species.

A genetic linkage map has been constructed for meadow fescue ( Festuca pratensis Huds.) (2n=2 x=14) using a full-sib family of a cross between a genotype from a Norwegian population (HF2) and a genotype from a Yugoslavian cultivar (B14). The two-way pseudo-testcross procedure has been used to develop separate maps for each parent, as well as a combined map. A total number of 550 loci have been mapped using homologous and heterologous RFLPs, AFLPs, isozymes and SSRs. The combined map consists of 466 markers, has a total length of 658.8 cM with an average marker density of 1.4 cM/marker. A high degree of orthology and colinearity was observed between meadow fescue and the Triticeae genome(s) for all linkage groups, and the individual linkage groups were designated 1F-7F in accordance with the orthologous Triticeae chromosomes. As expected, the meadow fescue linkage groups were highly orthologous and co-linear with Lolium, and with oat, maize and sorghum, generally in the same manner as the Triticeae chromosomes. It was shown that the evolutionary 4AL/5AL translocation, which characterises some of the Triticeae species, is not present in the meadow fescue genome. A putative insertion of a segment orthologous to Triticeae 2 at the top of 6F, similar to the rearrangement found in the wheat B and the rye R genome, was also observed. In addition, chromosome 4F is completely orthologous to rice chromosome 3 in contrast to the Triticeae where this rice chromosome is distributed over homoeologous group 4 and 5 chromosomes. The meadow fescue genome thus has a more ancestral configuration than any of the Triticeae genomes. The extended meadow fescue map reported here provides the opportunity for beneficial cross-species transfer of genetic knowledge, particularly from the complete genome sequence of rice.

Chromosome Mapping↗

PubMed2002

Physical and genetic mapping in the grasses Lolium perenne and Festuca pratensis.

A single chromosome of the grass species Festuca pratensis has been introgressed into Lolium perenne to produce a diploid monosomic substitution line 2n = 2x = 14. In this line recombination occurs throughout the length of the F. pratensis/L. perenne bivalent. The F. pratensis chromosome and recombinants between it and its L. perenne homeologue can be visualized using genomic in situ hybridization (GISH). GISH junctions represent the physical locations of sites of recombination, enabling a range of recombinant chromosomes to be used for physical mapping of the introgressed F. pratensis chromosome. The physical map, in conjunction with a genetic map composed of 104 F. pratensis-specific amplified fragment length polymorphisms (AFLPs), demonstrated: (1) the first large-scale analysis of the physical distribution of AFLPs; (2) variation in the relationship between genetic and physical distance from one part of the F. pratensis chromosome to another (e.g., variation was observed between and within chromosome arms); (3) that nucleolar organizer regions (NORs) and centromeres greatly reduce recombination; (4) that coding sequences are present close to the centromere and NORs in areas of low recombination in plant species with large genomes; and (5) apparent complete synteny between the F. pratensis chromosome and rice chromosome 1.

Chromosomes, Plant↗

PubMed2003

Diurnal variation in uptake and xylem contents of inorganic and assimilated N under continuous and interrupted N supply to Phleum pratense and Festuca pratensis.

Compensation by dark-period uptake of NH(4)(+) and NO(3)(-) in the grasses Phleum pratense L. and Festuca pratensis Huds. following N deprivation during the preceding light period was investigated in flowing solution culture under an artificial 10/14 h light/dark cycle. N was supplied as either NO(3)(-), NH(4)(+) or NH(4)NO(3) at 20+/-5 mmol m(-3), available continuously or only during the dark period, for 5-10 d. Intermittent N supply did not affect total daily N uptake, growth rate or net partitioning of dry matter. Net uptake and influx of NO(3)(-) varied similarly throughout the diurnal cycle when NO(3)(-) was supplied continuously, with a marginal contribution by NO(3)(-) efflux. Influx was significantly higher and efflux slightly higher following interruption of NO(3)(-) supply during the light period. Nitrate accounted for 80% of N in xylem exudate except between hours 6-9 of the light period when the amino acid concentration increased 3-fold, primarily as glutamine. Diurnal variation in relative NO(3)(-) uptake exhibited five phases of constant acceleration/deceleration, described reasonably well assuming NO(3)(-) influx was subject to metabolic co-regulation by NO(3)(-) and amino acid levels in the cytoplasmic compartment of the roots. Accordingly, influx is determined by variation in root NO(3)(-) levels throughout the dark period and the first half of the light period, but is down-regulated by increased amino acid levels during the second half of the light period. The sharp light/dark transitions affect transpiration rate and hence xylem N flux which, in turn, affect NO(3)(-) levels in the cytoplasmic compartment of the roots and the rate of NO(3)(-) assimilation in the shoot.

Circadian Rhythm↗

PubMed2003

Growth of endophyte, Neotyphodium, and its host plant, tall fescue (Festuca arundinacea), under 3D-clinorotation.

Growth of a filamentous fungus endophyte, Neotyphodium, and its host plant, tall fescue, Festuca arundinacea, was examined during the seed germination process under pseudo-microgravity [correction of micrgravity] generated by three dimensional (3D-) clinorotation. The shoot growth of tall fescue infected with the endophyte was remarkably suppressed on a 3D-clinostat compared with that of the ground control. Without being infected, shoot growth of tall fescue was not strongly affected by the 3D-clinorotation. Many aggregated hyphae were observed in the plant seed incubated for 1-day on the 3D-clinostat [correction of clinost] than in those kept on the ground. These results indicate that the clinorotation induces responses in the endophyte and its host plant different from those under normal gravity.

Festuca↗

PubMed2003

Poisoning of livestock in oregon in the 1940s to 1960s attributed to corynetoxins produced by Rathayibacter in nematode galls in chewings fescue (Festuca nigrescens).

Tunicaminyluracil antibiotics, similar to the corynetoxins produced by Rathayibacter toxicus in Australia and South Africa, were found in old nematode seed-galls from Festuca nigrescens from New Jersey (USA) and New Zealand (NZ). The toxin profiles from the NZ and USA galls were similar to each other, but differed from those produced by R toxicus from Australia and South Africa, suggesting that a geographical variant of R toxicus or closely related species may be involved. The NZ galls gave a positive response to a R toxicus-specific monoclonal antibody assay, albeit a considerably weaker response than that seen with Australian R toxicus galls, but the older USA galls were negative, possibly due to deterioration of the antigen. From these findings, it is postulated that livestock deaths associated with the feeding of nematode and bacterial infected screenings of F nigrescens in Oregon, USA, in the 1940s to 1960s were caused by corynetoxin-like toxins produced by the bacterium.

Actinomycetales↗

PubMed1991

Intergeneric somatic hybridization in Gramineae: somatic hybrid plants between tall fescue (Festuca arundinacea Schreb.) and Italian ryegrass (Lolium multiflorum Lam.).

Tall fescue (Festuca arundinacea Schreb.) protoplasts, inactivated by iodoacetamide, and non-morphogenic Italian ryegrass (Lolium multiflorum Lam.) protoplasts, both derived from suspension cultures, were electrofused and putative somatic hybrid plants were recovered. Two different genotypic fusion combinations were carried out and several green plants were regenerated in one of them. With respect to plant habitus, leaf and inflorescence morphology, the regenerants had phenotypes intermediate between those of the parents. Southern hybridization analysis using a rice ribosomal DNA probe revealed that the regenerants contained both tall fescue- and Italian ryegrass-specific-DNA fragments. A cloned Italian ryegrass-specific interspersed DNA probe hybridized to total genomic DNA from Italian ryegrass and from the green regenerated somatic hybrid plants but not to tall fescue. Chromosome counts and zymograms of leaf esterases suggested nuclear genome instability of the somatic hybrid plants analyzed. Four mitochondrial probes and one chloroplast DNA probe were used in Southern hybridization experiments to analyze the organellar composition of the somatic hybrids obtained. The somatic hybrid plants analyzed showed tall fescue, additive or novel mtDNA patterns when hybridized with different mitochondrial gene-specific probes, while corresponding analysis using a chloroplast gene-specific probe revealed in all cases the tall fescue hybridization profile. Independently regenerated F. arundinacea (+) L. multiflorum somatic hybrid plants were successfully transferred to soil and grown to maturity, representing the first flowering intergeneric somatic hybrids recovered in Gramineae.

Cells, Cultured↗