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Full-Text Articles in Plant Pathology
Response To Drought Of White Clover Lines Selected For Different Stolon Morphologies, H D. Karsten, J R. Caradus, D R. Woodfield
Response To Drought Of White Clover Lines Selected For Different Stolon Morphologies, H D. Karsten, J R. Caradus, D R. Woodfield
IGC Proceedings (1997-2023)
White clover (Trifolium repens L.) lines were selected from within large and small-leaved cultivars of Grasslands Kopu and Grasslands Tahora, respectively, for long or short internodes, and for high or low branching frequency from plants grown in sun and shade (50% full sunlight). Lines were compared for drought tolerance in a perennial ryegrass (Lolium perenne L.) sward in boxes. Prior to imposing drought branching frequency selections did not differ in branching frequency, although the low branching frequency selection had a higher percentage of rooted nodes. After an imposed drought treatment sun-selected lines grew better than shade-selected lines relative …
Breeding For Persistence In Lotus Corniculatus, M Rebuffo, N Altier
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., B Kindiger, C L. Dewald
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.
Protogynous Interval In Elephantgrass (Pennisetum Purpureum Schum.), A V. Pereira, R B. Barra, J C. Abreu, V De P. Freitas
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 …
Selection Of Interspecific Hybrids Of Brachiaria-A Tropical Forage Grass, C B. Do Valle
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 …
Increased Longevity Of Red Clover Through Selection For Persistence And Disease Resistance, R R. Smith
Increased Longevity Of Red Clover Through Selection For Persistence And Disease Resistance, R R. Smith
IGC Proceedings (1997-2023)
Red clover (Trifolium pratense L.), an excellent perennial forage legume, has been considered for many years to be a short-lived, two to three years, forage. Selection for resistance to foliar and root rot diseases and for longevity of stand over the past four decades has improved the persistence of the currently available cultivars. The present studies were conducted to evaluate the progress from selection for longevity and disease resistance. Selection for stand longevity and improved disease resistance has reliably extended the production of red clover into the third and fourth year. Selection for healthy plants in 3- or …
Selection For Field Survival Increases Freezing Tolerance In Festulolium, M D. Casler, P G. Pitts, P C. Bilkey, C A. Rose-Fricker
Selection For Field Survival Increases Freezing Tolerance In Festulolium, M D. Casler, P G. Pitts, P C. Bilkey, C A. Rose-Fricker
IGC Proceedings (1997-2023)
Festulolium (Festulolium braunii K.A.) is marginally adapted to the north central and northeastern USA and southern Canada. The purpose of this study was to evaluate four festulolium populations selected for field survival under harsh winter conditions for their freezing tolerance in controlled environments. Progenies of all four populations showed some improvement in freezing tolerance compared to their parents. Improvements were dependent on the temperature at which measurements were made and varied among germplasms. Improvements were manifested in both decreased plant mortality and decreased injury to surviving plants. Genetic variation for freezing tolerance appears to be a viable mechanism …
Current Red Clover Breeding Research, Heathcliffe Riday
Current Red Clover Breeding Research, Heathcliffe Riday
IGC Proceedings (1997-2023)
Red clover remains a globally important forage legume grown mostly in humid temperate climates on approximately 4 million ha. In the past 25 years global red clover seed production has stabilized around 10 million kg yr-1, although there is evidence that seed production is increasing globally at around 0.34 million kg yr-1 since the early 2000s. Globally many red clover programs exist targeting specific global regions with a focus on improving persistence, biomass yield, seed yield, and a few other minor traits. Breeding programs are increasing persistence by selecting for specific disease resistances, specific agricultural conditions such …
Germination And Seedlings Heterotrophic Growth Of Cocksfoot (Dactylis Glomerata L.) In Response To Temperature, Abraham Escobar-Gutiérrez, L. Q. Ahmed
Germination And Seedlings Heterotrophic Growth Of Cocksfoot (Dactylis Glomerata L.) In Response To Temperature, Abraham Escobar-Gutiérrez, L. Q. Ahmed
IGC Proceedings (1997-2023)
In the context of climate change, grasslands are considered, similar to forest, as an important sink for atmospheric CO2. However, environmental change seems to go faster than species adaptation to survive on site. Germination and heterotrophic growth are key phases for plant, and consequently, communities’ establishment and structure. They are under genetic control and affected by temperature. The objective of this study was to analyze the intra-specific variability of six accessions of Dactylis glomerata in their responses to eight constant temperatures (5 to 40˚C) during germination and initial heterotrophic growth. The novelty of this work comes from the …
The Economic Benefit Of Increased Yield And Digestibility In A Perennial C4 Grass, R. Mitchell, K. P. Vogel, G. Sarath
The Economic Benefit Of Increased Yield And Digestibility In A Perennial C4 Grass, R. Mitchell, K. P. Vogel, G. Sarath
IGC Proceedings (1997-2023)
Big bluestem (Andropogon gerardii Vitman) is a perennial C4 grass native to the North American tallgrass prairie (Weaver, 1954). It provides productive, high quality forage during late spring and summer in the Great Plains, USA (Mitchell et al., 1994). Increasing forage yield and digestibility can increase livestock performance and grassland profitability (Casler & Vogel, 1999). This study aimed to compare the economic value of 2 big bluestem strains developed by 3 generations of breeding for increased forage yield and digestibility with the base populations from which they were derived.
Preliminary Performance Of Panicum Maximum Accessions And Hybrids In Brazil, Liana Jank, Rosangela M. S. Resende, S. Calixto, M. M. Gontijo Neto, V. A. Laura, Manuel C. M. Macedo, Cacilda B. Do Valle
Preliminary Performance Of Panicum Maximum Accessions And Hybrids In Brazil, Liana Jank, Rosangela M. S. Resende, S. Calixto, M. M. Gontijo Neto, V. A. Laura, Manuel C. M. Macedo, Cacilda B. Do Valle
IGC Proceedings (1997-2023)
Due to the lack of high quality forages adapted to the distinct ecosystems in Brazil, a national network to evaluate 14 accessions, 4 hybrids and 5 commercial standards of Panicum maximum was established in 2002, in 5 regions of Brazil (states of Mato Grosso do Sul, Acre, Rondônia, Minas Gerais and in the Federal District). Staff of the Embrapa Beef Cattle group co-ordinated the network and pre-selected the accessions and hybrids (Jank, 1995; Jank et al., 2001; Resende et al., 2004). We present their performance as to leaf dry matter yield (LDMY) and leaf percentage (LP) obtained from …
Does Aflp Diversity Reflect Consanguinity Within Meadow Fescue Breeding Material?, B. Boller, R. Kölliker
Does Aflp Diversity Reflect Consanguinity Within Meadow Fescue Breeding Material?, B. Boller, R. Kölliker
IGC Proceedings (1997-2023)
Cultivars of perennial grass species are usually synthetics with a limited number of constituent parental clones, prone to inbreeding depression. Plant breeders aim at a balance between intensity of selection and maintenance of genetic diversity when making their choice of parent clones in an intuitive way, aided by fragmentary pedigree information. Molecular markers offer new opportunities for assessing genetic diversity among selected plants. The objective of the investigation presented here is to check if the genetic distance as measured by AFLP polymorphisms reflects consanguinity among Festuca pratensis individuals from our breeding programme.
Variability And Correlations Of Some Investigated Traits Of Perennial Ryegrass Populations, D. Sokolovic, S. Ignjatovic, Z. Tomic
Variability And Correlations Of Some Investigated Traits Of Perennial Ryegrass Populations, D. Sokolovic, S. Ignjatovic, Z. Tomic
IGC Proceedings (1997-2023)
Perennial ryegrass (Lolium perenne) is one of the most important perennial forage grasses for temperate climates. It is a highly productive grass with the highest nutritive value (Sokolovi et al., 2002). In Serbia, breeders have developed perennial ryegrass cultivars with high stabile yield and quality with different times of maturity and resistance to drought and frost. The initial breeding material were usually wild populations (Charmet et. al., 1996) with high variability and adaptability. These characteristics lend themselves for selection of superior genotypes. But breeding for some important agronomic traits may influence others. This relationship between traits …
Screening Genes For Association With Loci For Nitrogen-Use Efficiency In Perennial Ryegrass By PyrosequencingTm, O. Dolstra, D. Dees, J. -D. Driesprong, E. N. Van Loo
Screening Genes For Association With Loci For Nitrogen-Use Efficiency In Perennial Ryegrass By PyrosequencingTm, O. Dolstra, D. Dees, J. -D. Driesprong, E. N. Van Loo
IGC Proceedings (1997-2023)
The application of marker-assisted selection to improve quantitative traits in perennial ryegrass (Lolium perenne) is cumbersome. It requires a priori knowledge on the association of markers and genes. The knowledge on the chromosomal location of major genes for quantitative traits as well as on gene sequences is rapidly growing. However, determination of the genetic constitution of parents prior to their use in breeding still is impractical. More realistic is to collect association data along with the testing activities needed for breeding new varieties. This study uses changes in allele frequency due to selection as a criterion for gene-trait …
Marker-Assisted Selection For Fibre Concentration In Smooth Bromegrass, C. Stendal, M. D. Casler, G. Jung
Marker-Assisted Selection For Fibre Concentration In Smooth Bromegrass, C. Stendal, M. D. Casler, G. Jung
IGC Proceedings (1997-2023)
The concentration of neutral detergent fibre is the best single laboratory predictor of voluntary intake potential in forage crops. However, the assay of thousands of plant samples for NDF selection in a breeding program requires a large amount of labour and time, potentially increasing cycle time and reducing the rate of progress. A previous study (Diaby and Casler, 2005) identified 16 random amplified polymorphic DNA (RAPD) markers that were strongly associated with NDF concentration in one or more of four smooth bromegrass (Bromus inermis Leyss) populations. The objective of this study was to validate these associations by implementing marker-assisted …