Inheritance of bud-set and bud-flushing in Picea abies (L.) Karst

Area of Science:

• Forest genetics
• Plant physiology
• Quantitative genetics

Background:

• Norway spruce (Picea abies) provenances exhibit distinct photoperiodic and temperature responses.
• French provenance: long critical night length for bud-set, late bud flushing.
• Swedish provenance: short critical night length for bud-set, early bud flushing.

Purpose of the Study:

• Investigate the genetic basis of photoperiodic and temperature responses in Picea abies.
• Determine the inheritance patterns (additive vs. non-additive gene action) in interprovenance crosses.
• Assess the potential for breeding improved Norway spruce varieties.

Main Methods:

• Diallel crosses between French and Swedish Picea abies provenances.
• Growth trials of F1 hybrid seedlings and intraprovenance half-sibs in a phytotron.
• Evaluation of photoperiodic control of bud-set and temperature requirements for bud-flushing over three growth periods.

Main Results:

• Hybrid progenies showed intermediate photoperiodic and temperature responses compared to intraprovenance half-sibs.
• Additive gene action appears prevalent in determining these traits.
• Individual hybrid combinations displayed varied responses, with some matching intraprovenance levels.

Conclusions:

• Interprovenance crosses in Picea abies result in intermediate adaptive traits, suggesting additive genetic control.
• Careful parent selection in interprovenance crosses can yield hybrids with specific, desired photoperiodic and temperature adaptations.
• This offers a strategy for breeding Norway spruce with enhanced suitability for different environments.