Morphological Characteristic to Discriminate \u3cem\u3eFestulolium\u3c/em\u3e Hybrids (\u3cem\u3eFestuca Pratensis\u3c/em\u3e × \u3cem\u3eLolium Perenne\u3c/em\u3e)

Environmental change and uncertainty is likely to pose new challenges in plant breeders. Recently attention has focused on the crossing of Lolium and Festuca species to obtain hybrids exhibiting many desirable traits of both parents. Key objectives of such programs are to combine the persistency, winter hardiness and drought tolerance of fescues with the high herbage yields and quality of ryegrasses (Zwierzykowski, Naganowska, 1994). One of the hybrids with great practical significance is a F. pratensis × L. perenne hybrid [Festulolium loliaceum (Huds.) P.V. Fourn]. Many morphological traits of Festulolium hybrids demonstrate intermediate character, however, in relation to inflorescence type they are similar to L. perenne; the hybrids and perennial ryegrass have spike-like inflorescences, though they may be rarely a little-branched. Occurrence of a reduced inner glume in hybrid spikelets is a trait, which enables discrimination between Festulolium and L. perenne plants. The aim of this work was to analyse the morphological trait of inflorescences to aid the identification of the hybrids Festulolium in relation to L. perenne

Impact of cold-induced antioxidant activity on frost resistance in androgenic Festulolium genotypes

The aim of the study was: (i) to state if selected in the field conditions androgenic Festulolium genotypes are diverse in frost tolerance, and (ii) to investigate if changes in anitoxidant activity could be recognized as a physiological marker of this type tolerance. Antioxidative system induced by prehardening (12°C) and hardening (2°C) temperatures was investigated in 6 androgenic genotypes generated from a Festuca pratensis × Lolium multiflorum (2n = 4x = 28) amphidiploid hybrid (four genotypes derived from the F1 hybrids, and two genotypes derived from the Festulolium cultivar ‘Rakopan’). The electrolyte leakage, frost resistance expressed as the values of temperature causes 50% damages (LT50), the activities of superoxide dismutase (SOD), catalase (CAT), non-specific peroxidase (PX) and ascorbate peroxidase (APX) were measured. The results obtained indicated weak diversity of frost tolerance among studied androgenic genotypes. Only the one genotype was chosen as the most resistant to frost, while the other genotypes demonstrated no significant differences in values of LT50 coefficient recorded after hardening. Prehardening temperature of 12°C caused an increase in cell membrane permeability in all genotypes studied. After hardening ion leakage from cells declined up to the control level. Generally, cold activated SOD, PX and APX in leaves of the genotypes studied, and inhibited strongly CAT activity. The most frost tolerant genotype was characterized by high PX activity after hardening process.Abbreviations: APX – ascorbate peroxidase, CAT – catalase, EDTA – ethylenediaminetatraacetic acid, LT50 – letal temperature causing 50% membrane cell damages, NBT – nitroblue tetrazolium, PPFD – photosynthetic photon flux density [μmol m-2 s-1], PX – non-specific peroxidase, RH – relative humidity, ROS – reactive oxygen species, SE – standard error, SOD – superoxide dismutas

Locating, and Utilising \u3cem\u3eFestuca Pratensis\u3c/em\u3e Genes for Winter Hardiness for the Future Development of More Persistent High Quality \u3cem\u3eLolium\u3c/em\u3e Cultivars

Genes for freezing-tolerance and winter hardiness were located in Festuca pratensis by QTL analysis and introgression-mapping. QTL for freezing-tolerance on F. pratensis chromosome 4 were orthologous to rice chromosome 3, and Triticeae chromosome 5. Increased energy dissipation during the autumn through a lower maximum quantum yield of photosystem II (PSII) was correlated with improved winter survival. Freezing tolerance in Lolium was achieved by the transfer and subsequent expression of F. pratensis genes from chromosome 4 that govern the expression of a non-photochemical (NPQ) mechanism for the dissipation of excess light energy under low temperature

Interspecific and intergeneric hybrids of the Lolium - Festuca complex obtained in Poland in the years 1964-1994 and maintained in the collection at the Institute of Plant Genetics in Poznan

In the years 1964-1994 an extensive programme of wide hybridization within Ihe. Lolium-Festuca complex was carried out in Poland. Six Lolium (ryegrass) and five Festuca (fescue) species at different ploidy level were used for crosses. Hybrids were obtained from 72 cross combinations: 19 interspecific (five Lolium × Lolium and 14 Festuca × Festuca), 51 intergeneric (39 Lolium × Festuca and 12 Festuca × Lolium) and two trispecific (Lolium × Festuca × Festuca), most of them being derived from crosses of four important forage grass species: Lolium multiflorum, L. perenne, Festuca pratensis and F. arundinacea. Interspecific and intergeneric Lolium-F estuca hybrids from 50 cross combinations are maintained at present in the collection of the Institute of Plant Genetics in Poznań. This article presents a complete list of Lolium-Festuca hybrids obtained in Poland in the years 1964-1994 and maintained in the collection. The available literature concerning these hybrids is cited

Plant regeneration from immature inflorescence-derived callus of Italian ryegrass [Lolium multiflorum Lam.]: chromosome number and fertility of regenerated plants

Twenty field-grown genotypes of diploid Italian ryegrass (Lolium multiflorum Lam., 2n = 2x = 14) were tested for their ability to induce callus and regenerate plants. Callus cultures were initiated from segments of immature inflorescences cultured on the MS medium supplemented with 4.0 mg L⁻¹ 2,4-D. The calluses were subcultured first on the maintaining medium (MS medium with 2.0 mg L⁻¹ 2,4-D) and later on the rooting medium (MS medium with 0.2 mg L⁻¹ 2,4-D). The frequency of callus induction varied depending on the source of explant and the initial genotype. A total of 473 green plantlets were regenerated, of which 420 were established in the soil. All these plants had the morphological characteristics of Italian ryegrass. Among 372 regenerants analysed cytologically, 302 (81.2%) had the expected diploid chromosome number (2n = 2x= 14), 65 (17.5%) were tetraploid (2n = 4x = 28); several aneuploids and mixoploids were also observed. All diploid and tetraploid regenerants were male and female fertile. However, a great variation of female fertility within and between both groups of regenerants was observed