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Articles 1 - 7 of 7
Full-Text Articles in Physical Sciences and Mathematics
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 …