Browsing by Subject "growth rate"

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  • Kärkkäinen, Matti (Suomen metsätieteellinen seura, 1984)
  • Pihlaja, Tuomo (University of Helsinki, 1999)
  • Ruusunen, Marita; Puolanne, Eero (Elsevier, 2004)
    This study reports the results of a comparison of the histochemical properties of various types of porcine muscles in wild and domestic pigs. In domestic pigs, the influence of growth rates on these properties were studied in five muscles: longissimus dorsi (LD), semimembranosus (SM), gluteus superficialis (GS), infra spinam (IS) and masseter (MAS). The growth rate was expressed as (i) live weight (LW) at 165 ± 2d and (ii) daily LW gain from day 88 to day 165 (DG) on the experimental diet. LD, SM, GS and IS of wild pigs were found to contain a higher area percentage of oxidative type IIA fibres (type IIA%area) and a lower percentage area of glycolytic type IIB fibres (type IIB%area) than the same muscles of domestic pigs. The capillary density in the light muscles (LD, SM, GS) of wild pigs was twice that of domestic pigs, indicating higher oxidative capacity. In domestic pigs the cross sectional area of type IIB fibres (CSAIIB) was markedly larger than the cross sectional area of type I (CSAI) and IIA (CSAIIA) fibres. The average fibre cross sectional area (CSAfibre) was about the same in the muscles of wild and domestic pigs except in LD and SM, where the average fibre cross sectional area was approximately 25% smaller in wild pigs than in domestic pigs. This difference was caused by the large cross sectional area of type IIB fibres in the light muscles of domestic pigs. In the light muscles of domestic pigs, the cross sectional area of type IIA fibres increased most with increasing growth rate. Growth rate influences muscle fibre properties only in light muscles, not in dark muscles.
  • Palmgren, Kristina; Saarsalmi, Anna; Weber, Assi (Suomen metsätieteellinen seura, 1985)
  • Ramirez-Valiente, Jose Alberto; Sole-Medina, Aida; Pyhäjärvi, Tanja; Cervantes, Sandra; Kesalahti, Robert; Kujala, Sonja T.; Kumpula, Timo; Heer, Katrin; Opgenoorth, Lars; Siebertz, Jan; Danusevicius, Darius; Notivol, Eduardo; Benavides, Raquel; Robledo-Arnuncio, Juan Jose (2021)
    Understanding the dynamics of selection is key to predicting the response of tree species to new environmental conditions in the current context of climate change. However, selection patterns acting on early recruitment stages and their climatic drivers remain largely unknown in most tree species, despite being a critical period of their life cycle. We measured phenotypic selection on Pinus sylvestris seed mass, emergence time and early growth rate over 2 yr in four common garden experiments established along the latitudinal gradient of the species in Europe. Significant phenotypic plasticity and among-population genetic variation were found for all measured phenotypic traits. Heat and drought negatively affected fitness in the southern sites, but heavy rainfalls also decreased early survival in middle latitudes. Climate-driven directional selection was found for higher seed mass and earlier emergence time, while the form of selection on seedling growth rates differed among sites and populations. Evidence of adaptive and maladaptive phenotypic plasticity was found for emergence time and early growth rate, respectively. Seed mass, emergence time and early growth rate have an adaptive role in the early stages of P. sylvestris and climate strongly influences the patterns of selection on these fitness-related traits.