Evaluating Cultivars Of Subterranean Clover In Monoculture Or With Perennial Ryegrass,
2024
Agriculture Victoria, Australia
Evaluating Cultivars Of Subterranean Clover In Monoculture Or With Perennial Ryegrass, K F.M. Reed, S G. Clark, W M. Feely
IGC Proceedings (1997-2023)
Over four years, sowing perennial ryegrass (Lolium perenne) with a range of subterranean clover (“sub clover”, Trifolium subterraneum) cultivars was found to reduce the yield of clover per se by 31% and increase pasture yield by 11%. For one high-producing experimental variety, the presence of grass did not reduce clover yield (P<0.001). Clover yield in monoculture plots was poorly correlated with that measured in mixed swards (r = 0.44), but clover yield (± grass) was correlated with total herbage yield (r = 0.94). Clover seed yield was not reduced by the presence of grass. However, in year 2 - but not in the establishment year - grass reduced seed weight. Irrespective of grass treatment, the new late maturing cultivar, Leura outyielded the other commercial cultivars (P<0.05). Enfield and Enfield x Daliak crosses set the most seed and regenerated with a greater density than other cultivars (P<0.05) - apart from Leura. It was concluded that the winter-active, late maturing cultivar, Leura, will compete most successfully with perennial ryegrass.
Gene Flow In Medicago Through Somatic Hybridization,
2024
Istituto di Ricerche sul Miglioramento Genetico delle Piante Foraggere
Gene Flow In Medicago Through Somatic Hybridization, S Arcioni, F Crea, O Calderini, F Damiani, P D. Cluster, F Pupilli
IGC Proceedings (1997-2023)
The objective of this research was the characterization at both molecular and phenotypic level of three somatic hybrid plants obtained by electrofusion of protoplasts of Medicago sativa with those of M.coerulea, M.falcata and M.arborea, three Medicago species in a different relation with alfalfa. Different kinds of rearrangements including the amplification of new spacer-length variants were detected at rDNA loci in the somatic hybrids. Analysis of field performances confirmed the suitability of these plants for breeding purposes.
Ssr- And Rapd Analysis Of A New Agropyron Repens Genotype,
2024
Agricultural University, Hungary, Purdue University
Ssr- And Rapd Analysis Of A New Agropyron Repens Genotype, G Gyulai, H Ohm, I Dweikat, E Kiss, H Sharma, J Janovszky, L Heszky
IGC Proceedings (1997-2023)
SSR-(single sequence repeat), and RAPD (randomly amplified polymorphic DNA) primer generated DNA fingerprints were used to distinguish a new genotype of quackgrass from its original type of Agropyron repenes L. Beauv. (= Elytrigia repens). Products of polymerase chain reactions (PCR) were separated by agarose (AGE) and denaturing gradient gel electrophoresis (DGGE). Although, both kinds of primers were found to be polymorphic, the microsatellite primer with sequence of 5í-AC(GACA)4-3í generated distinguishing fingerprints in the two types of quackgrasses. This result gives genetic evidence for the new genotype of quackgrass.
Screening Ryegrass Cultivars For Aluminium Sensitivity In Nutrient Soluations,
2024
Department de Ciencias Quimicas
Screening Ryegrass Cultivars For Aluminium Sensitivity In Nutrient Soluations, F O. Gallardo, S Benavides, R Demanet, F Borie
IGC Proceedings (1997-2023)
The objective of this study was to evaluate Al and H+ tolerance of nine ryegrass (Lolium perenne and L. multiflorum) cultivars by growing plants in a mineral solution (pH 4.8 and 6.0 and 0-200 (M Al). Results showed that Yatsyn-1, with a relative root length of 91 was the cultivar least affected by acidity (H+), and Concord ( RRLpH = 58) was the cultivar with the highest H+ sensitivity. In connection with Al-tolerance, Yatsyn-1 and Concord, were the most tolerant cultivars with 88 and 87 RRLAl, respectively whereas Nui and Marathon, were the most sensitive ones, reaching only …
Breeding For Persistence In Lotus Corniculatus,
2024
INIA La Estanzuela, Uruguay
Breeding For Persistence In Lotus Corniculatus, M Rebuffo, N Altier
IGC Proceedings (1997-2023)
The objectives of this study were to develop a more persistent germplasm of birdsfoot trefoil (Lotus corniculatus L.) and to evaluate its potential use in Uruguay. Two cycles of phenotypic recurrent selection were done under field conditions. Eight hundred and 1600 spaced plants were established for the first and second cycle of selection. Both nurseries were visually assessed for crown rot, relative growth, plant habit and foliar diseases. The final selection of the breeding population LE 65-56 includes thirty six plants selected from sixteen elite families. This selection was more persistent and productive than the check varieties in plot …
Apomixis And The Reproductive Dynamics Of Eastern Gamagrass Tripsacum Dactyloides L.,
2024
USDA, Agricultural Research Service
Apomixis And The Reproductive Dynamics Of Eastern Gamagrass Tripsacum Dactyloides L., B Kindiger, C L. Dewald
IGC Proceedings (1997-2023)
Studies were conducted to determine the reproductive characteristics of Tripsacum, a perennial, native pasture species and to identify methods for breeding agronomically superior cultivars. Reproductive methods and types of individuals generated were evaluated with triploid and hexaploids possessing a novel method for transferring sexual germplasm into apomictic tetraploids and tetraploid germplasm into sexual diploids. Triploids and hexaploids are demonstrated to be useful materials for introgressing and transferring desirable alleles across ploidy levels and reproductive barriers.
Cytogenetical Studies In Range Grasses Of Iran,
2024
University of Shahid Beheshti
Cytogenetical Studies In Range Grasses Of Iran, M Sheidai, A Tavasoli, P Derakhshandeh
IGC Proceedings (1997-2023)
Cytogenetical and breeding studies of range grasses are in hand. Present article describes preliminary cytogenetical analysis of wheatgrass (Agropyron) and bromegrass (Bromus) taxa (Agropyron trichophorum n = 21, A. pectinoforome n = 21), two different populations of A. repens (n = 28) and Bromus stenostachyus (n = 14). The species varied with regard to chiasma number and distribution. The highest value occurred in A. repens (Mako population). Heterogenity test for the paired samples showed lack of heterogenity for chiasmata indicating homogenity of Agropyron taxa. However a test for ring and rod bivalents showed significant differences …
Direct Selection Response For Stem Rust Resistance In Tall Fescue,
2024
Oregon State University
Direct Selection Response For Stem Rust Resistance In Tall Fescue, R E. Barker, R E. Welty
IGC Proceedings (1997-2023)
Resistance to stem rust (caused by Puccinia graminis Pers.: Pers. subsp. graminicola Z. Urban.) would be beneficial in tall fescue (Festuca arundinacea Schreb.). Two cycles of polycross (PX) selection on progenies from thirty-four parent plants (14 forage-types and 20 turf-types) were compared to one cycle of open pollination (OP) followed by one cycle of PX selection using a 2-stage greenhouse screening process. Response from selection was determined from composite half-sib progenies from each cycle. Number of plants with resistant reaction based on pustule type increased from 5 to 54% in the PX forage-type population and from 6 to 50% …
Assessment Of Grazing Procedures In The Evaluation Of Plant Breeding Material,
2024
Pasture Research Programme, INIA, Uruguay
Assessment Of Grazing Procedures In The Evaluation Of Plant Breeding Material, D Real, I L. Gordon, J Hodgson
IGC Proceedings (1997-2023)
Four stocking densities (2, 3, 5 and 9 sheep/18 m2 for one hour) and two times of grazing (morning or evening) were imposed on a spaced plant nursery of nine red clover (Trifolium pratense L.) populations of varying growth habit, in order to optimize measurement of sheep grazing preference. Plant height, spread and leafiness were measured before and after each of three grazings. Sheep preference was viewed multivariately, using combined measurements of these plant characteristics. MANOVA revealed that the effect of stocking density was significant (P-0.05), but that of time of grazing was not. The plant, population and overall …
Developing Well Adapted Early To Midseason Cultivars Of Trifoiloum Subterraneum Ssp. Brachycalycinum,
2024
South Australian Research Development Institute (SARDI)
Developing Well Adapted Early To Midseason Cultivars Of Trifoiloum Subterraneum Ssp. Brachycalycinum, C T. De Koning, P G.H. Nichols, R L. Tuckwell, N Schubert
IGC Proceedings (1997-2023)
Development and selection of early to midseason cultivars of subterranean clover (Trifolium subterraneum L.) ssp. brachycalycinum has mostly involved the use of early generation selection nursery swards (F2-progeny method). Four sites were sown in the mid-North region of South Australia. At the end of 1995, the top 20 lines from each site had burrs (seed pods) sampled at random. The burr will proceed into the final early generation selection phase (1 - 2 years). Dependent on the site, many lines have out-performed the standard checkplot cultivar, Clare. High hardseed levels have also been incorporated into 1989 crossbreds.
Regeneration Of Somatic Hybrids Between Festuca Arundinacea Var. Glacescens And Lolium Multiflorum Lam.,
2024
Forage Crop Breeding and Seed Research Institute, Japan
Regeneration Of Somatic Hybrids Between Festuca Arundinacea Var. Glacescens And Lolium Multiflorum Lam., T Sasaki, T Hasegawa, S Ueda
IGC Proceedings (1997-2023)
Protoplasts derived from ten suspension cultures of tetraploid Festuca arundinacea var. glaucescens (2n = 4x = 28) and diploid Lolium multiflorum Lam. (2n = 2x =14) were fused to produce somatic hybrids. Regenerated green plants in three fusion combinations were identified as somatic hybrids because they showed characters that were peculiar to both Festuca arundinacea var. glaucescens (hairs on auricle) and Lolium multiflorum Lam. (root-fluorescence). Moreover, the hybrids also had a chromosome number of about forty two.
Breeding Morphogenetic Traits To Match Genotypes To Their Utilization,
2024
INRA Amélioration des plantes fourragères
Breeding Morphogenetic Traits To Match Genotypes To Their Utilization, L Hazard, M Betin, M Ghesquiere
IGC Proceedings (1997-2023)
A divergent selection for lamina length was done from natural populations of perennial ryegrass. Tested in a multi-site experiment in France, the short-leaved perennial ryegrass was more productive under simulated grazing and less productive under infrequent cutting than the long-leaved perennial ryegrass. Matching cultivars to their management is possible by selecting for morphogenetic traits. However, our results suggest the range of adaptation to different managements of perennial ryegrass cultivars could be extended by increasing their phenotypic plasticity.
Improving Forage Productivity By Using Cytoplasmic Male Sterility Of Pearl Millet,
2024
Field Crops Research Institute, Egypt
Improving Forage Productivity By Using Cytoplasmic Male Sterility Of Pearl Millet, A A. Younis, A H. Belal
IGC Proceedings (1997-2023)
Fourteen forage millet hybrids were produced by crossing 7 male fertile lines to 2 different lines of dwarf cytoplasmic male sterile (cms) lines of forage millet (Pennisetum americanum). Hybrids were evaluated with their male parents at the Giza experimental station in summer 1994. The evaluations included fodder yield traits and chemical composition. The objectives of the study were: 1 - to assess hybrid vigor, and 2 - to select the superior hybrids to be used in commercial production in Egypt. Present results showed that the 14 F1 hybrids and their male parents varied significantly in green and dry …
Protogynous Interval In Elephantgrass (Pennisetum Purpureum Schum.),
2024
EMBRAPA, Brazil
Protogynous Interval In Elephantgrass (Pennisetum Purpureum Schum.), A V. Pereira, R B. Barra, J C. Abreu, V De P. Freitas
IGC Proceedings (1997-2023)
A study was carried out to examine the protogyny duration in elephantgrass inflorescences. Nine accessions were selected, divided into three groups, according to early, intermediate or late flowering. From each cultivar, 10 panicles were sampled for evaluation. The criterion for estimating the duration of protogyny was the time interval (number of days) from the first visual detection of exserted stigmas up to the first visual appearance of open anthers (±5%). Duration of protogyny averaged 7.43±1.37 d, confirming that the species is protoginous. Late flowering accessions exhibited an average of 8.97 d for the duration of protogyny, which was significantly higher …
Evolution In Segregating Genotype Mixtures Of Subterranean Clover,
2024
University of Western Australia
Evolution In Segregating Genotype Mixtures Of Subterranean Clover, P.G. H. Nichols, P S. Cocks
IGC Proceedings (1997-2023)
A complex segregating mixture of subterranean clover (Trifolium subterraneum L.), was sown in 1978 at Nabawa and Mt Barker, two contrasting sites in Western Australia. Seed harvested from both sites from 1980-1994 was grown out at Shenton Park in 1995, along with seed of the original mixture. Populations diverged markedly for mean days to first flowering (DFF) within three seasons. No further trends in mean DFF occurred in plants derived from the next 14 years, although standard deviation declined significantly in plants from Mt Barker. Between season differences in mean DFF were correlated with estimated growing season length at …
Prediction Of Seed Yield Of Festuca X Lolium Hybrids From The Nursery Mother Plants,
2024
INRA Amélioration des Plantes Fourragères, France
Prediction Of Seed Yield Of Festuca X Lolium Hybrids From The Nursery Mother Plants, C Mousset, L Hazard, M Ghesquiere
IGC Proceedings (1997-2023)
In order to develop commercial Festuca x Lolium hybrids, their seed production has to be improved. Seed yields of Festuca x Lolium progenies were assessed in dense plots. Prediction of those seed yields was based on the morphological observations done on spaced plants in the nursery of both mother plants and their progenies. The best prediction of the progeny seed yields is a linear regression on the stem density and the seed weight per inflorescence assessed on the mother plants.
Use Of Flow Cytometer In Breeding Festuca X Lolium Hybrids,
2024
INRA Station d’ Amélioration des Plantes Fourragères, France
Use Of Flow Cytometer In Breeding Festuca X Lolium Hybrids, M C. Kerlan, M Ghesquiere
IGC Proceedings (1997-2023)
Ploidy in various generic Lolium - Festuca progenies were assessed by flow cytometry and compared to conventional chromosome counting. In non-segregating triploid and tetraploid progenies, the cytometer estimated so accurately the level of plant ploidy that chromosomes counting would be no use. In segregant progenies, all the tetraploid plants according to the cytometer had effectively 28 chromosomes. Among the triploid and pentaploid plants detected by the cytometer, 40% of the plants were tetraploid. They represented only 29% of the progeny which must be counted. The flow cytometry can be used in routine interspecific breeding programmes. Conventional chromosome counting should be …
Persistency In Lolium X Festuca Hybrid Derivatives And Its Relationships With Flowering Traits,
2024
Station d’Amélioration des Plantes Fourragères, France
Persistency In Lolium X Festuca Hybrid Derivatives And Its Relationships With Flowering Traits, M Ghesquiere, C Mousset
IGC Proceedings (1997-2023)
Using amphiploid and backcrossed derivatives of Italian ryegrass x tall fescue hybrids, the paper emphasizes the interest of introgression vs amphiploidization in breeding for specific traits such as persistency or seed production from tall fescue or ryegrass resp. Persistency in amphiploid and Lolium-introgressed progenies were assessed in nursery together with variation of flowering traits. Persistency was found lower, on average, in introgressed progenies than in hybrid progenies but with enlarged variability within progeny suggesting possible advantageous rearrangements of fescue chromosomes. Although significantly associated, persistency in both populations was only very little affected by the variations in flowering traits such …
Field Evaluation Of Crown Rust In Annual Ryegrass Populations,
2024
University of Florida
Field Evaluation Of Crown Rust In Annual Ryegrass Populations, G M. Prine
IGC Proceedings (1997-2023)
Crown rust (Puccinia coronata [Pers.] Cda.) is the most prevalent disease found on annual ryegrass (Lolium multiflorum L.) of the southeastern USA. Determination of crown rust resistance is difficult because of the erratic nature of infections at most locations. As crown rust is present at Gainesville, FL each year, a rust nursery was designed to evaluate rust resistance and susceptibility of annual ryegrass. Evaluation consists of periodic rust ratings of the seed crop and regrowth of part of each plot after cutting. Nursery results indicate the buildup of rust, including at the date of 90% heading (start of …
Selection Of Interspecific Hybrids Of Brachiaria-A Tropical Forage Grass,
2024
EMBRAPA/CNPGC
Selection Of Interspecific Hybrids Of Brachiaria-A Tropical Forage Grass, C B. Do Valle
IGC Proceedings (1997-2023)
The aim of the breeding program at the National Beef Cattle Research Center (CNPGC) of the Brazilian Corporation for Agricultural Research (EMBRAPA), is to produce vigorous apomictic hybrids with wide edaphic adaptation, good production and nutritive value combined with spittlebug (Homoptera:Cercopidea) resistance. Fiftysix superior hybrids were selected based on visual estimates of vigor, leafiness, tolerance to drought and natural spittlebug infestation in the field. These were characterized for mode of reproduction, spittlebug reaction under controlled conditions and for morphological diversity using nine selected traits. Multivariate analysis classified the population into seven groups where the hybrids were clearly intermediate in plant …
