Heritability of Physical Properties and Other Quality Traits in Timothy

Surprenant, J.; Michaud, R.; Allard, G.; St-Pierre, C.

doi:10.4141/cjps90-084

Cited by 4 publications

(1 citation statement)

References 15 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Surprenant et al (1990b) observed significant variation among half-sib families for CP, IVDMD, NDF, and ADF. Surprenant et al (1990a) also observed significant variation for DM digestibility, CP, ADF, and NDF following one cycle of divergent phenotypic selection for CP, digestibility and digestible yield. No North American cultivar has been selected for digestibility (Berg et al 1996).…”

Section: Breeding Genetic Variability For Individual Traitsmentioning

confidence: 98%

Improving the nutritive value of timothy through management and breeding

Bélanger¹,

Michaud²,

Jefferson³

et al. 2001

Can. J. Plant Sci.

Self Cite

View full text Add to dashboard Cite

2001. Improving the nutritive value of timothy through management and breeding. Can. J. Plant Sci. 81: 577-585. Timothy (Phleum pratense L.) is a widely grown forage grass species in cool and humid regions of the world including northeastern and northwestern North America, Nordic countries, Russia, and Japan. The nutritive value of timothy decreases with time, phenological development, and increasing forage yield. This review paper summarizes methods of controlling or improving the nutritive value of timothy through management practices and genetic selection, while keeping in mind the importance of forage yield. Consequently, the nutritive value of timothy is considered in relation to the accumulation of forage yield. The ecophysiological basis for the decrease in nutritive value with increasing forage yield during a growth cycle is presented with the assumption that the forage is made of two components: metabolic and structural. The decrease in the proportion of the metabolic component with increasing forage yield reduces the nutritive value of timothy. The nutritive value is also affected by the N concentration of the metabolic component, and by the digestibility of the structural component. Harvest dates, growing seasons, N fertilization, and cultivars have an indirect effect on the nutritive value of timothy through increased forage yield and the change in the proportion of the metabolic and structural components, but they also have a direct effect on each component. The results presented demonstrate the possibility of dissociating yield and nutritive value by plant breeding and, therefore, to improve the nutritive value of timothy while maintaining forage yield. Nord, les pays scandinaves, la Russie, et le Japon. La valeur nutritive de la fléole des prés diminue avec le temps, le développement phénologique, et l'accumulation de rendement. Cet article de synthèse présente des façons de contrôler ou d'améliorer la valeur nutritive de la fléole des prés par la régie et la sélection génétique sans toutefois négliger l'importance du rendement. Ainsi, la valeur nutritive de la fléole des prés est considérée en relation avec l'accumulation du rendement fourrager. La base écophysiologique de la diminution de la valeur nutritive avec l'augmentation du rendement durant un cycle de croissance est présentée en faisant l'hypothèse que la biomasse aérienne est formée de deux composantes: métabolique et structurale. La diminution de la proportion de la composante métabolique avec l'augmentation du rendement réduit la valeur nutritive. La valeur nutritive est aussi affectée par la teneur en azote de la composante métabolique, et par la digestibilité de la composante structurale. Les dates de coupe, la saison de croissance, la fertilisation azotée et les cultivars ont un effet indirect sur la valeur nutritive de la fléole des prés via une augmentation du rendement et un changement de la proportion des composantes métaboliques et structurales, mais ils ont de plus un effet direct sur chacune de ces deux dernières composantes...

show abstract

Section: Breeding Genetic Variability For Individual Traitsmentioning

confidence: 98%

Improving the nutritive value of timothy through management and breeding

Bélanger¹,

Michaud²,

Jefferson³

et al. 2001

Can. J. Plant Sci.

Self Cite

View full text Add to dashboard Cite

show abstract

Effects of competitive stress on vegetative growth, storage, and regrowth after defoliation in Phleum pratense

Cheplick¹,

Chui²

2001

Oikos

View full text Add to dashboard Cite

The capacity for resource storage is important to population persistence in nonforaging plants with a consolidation strategy. In a competitive environment, selection may favor genetic variants with a well‐developed ability to store resources for future vegetative growth or to regrow following herbivory. To determine the evolutionary potential for changes in vegetative growth, storage and regrowth after defoliation in response to competitive stress, half‐sib families of the caespitose grass Phleum pratense were grown in pots in a glasshouse either alone or in competition with four individuals of Lolium perenne. They were defoliated after 16 wk and permitted to regrow for 8 wk. Production of new tillers, leaf area and leaf dry mass were recorded before and after defoliation; resource storage was estimated by the dry mass of stem bases. Tiller numbers, leaf area and mass, regrowth, and stem base mass were significantly reduced by competition; however, there was significant variation among families for many variables. A significant proportion of the variation in clipped and regrowth leaf mass, and in stem base mass, was due to a competition by family interaction. Storage in stem bases was correlated with total accumulated leaf mass in both control and competition groups. Genetic variation for competitive ability and the ability to regrow rapidly after defoliation exist in this P. pratense population. A well‐developed ability to regrow following release from competitive or grazing pressures is likely to be a critical adaptation of caespitose grasses.

show abstract