Early prediction of stem form in hybrid larch
2002
Bastien, Catherine | Pâques, Luc E. | Unité de recherche Amélioration, Génétique et Physiologie Forestières (AGPF) ; Institut National de la Recherche Agronomique (INRA) | INRA
Report : Towards au European larch wood chain : 1998-2002 Final report
显示更多 [+] 显示较少 [-]英语. Stem form is a major selection criterion in larch breeding. However crookedness, the most common defect is difficult to evaluate and often unfavourably linked to growth. In order to identify early predictors of stem form, detailed observations and measurements of growth rhythm and stern crookedness were done during six years in a retrospective test including 62 L. eurolepis clones.Most of bending defects appeared at the end of the growing season in the upper part of the shoot. They were also located on the first quarter of the shoot as reaction to defects on the previous annual shoot. The number of sylleptic branches which indicated high annual growth rate was unfavourably linked to the annual crookedness score. More than 70% of defects remained after a 3 or 5-year period. However few clones showed high ability to correct external appearance through radial growth. Repeatability of annual shoot crookedness gave a better discrimination between clones than a global score cumulating defects along the stem. Evaluation of stem crookedness after two years of fast growth in nursery test was significantly related to stem crookedness at age 16 in the field. Early prediction was greatly improved when repeatability of bending defects was evaluated over a 5-year period.
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