Measurement of fruit surface colour in ‘Gala’ apple (Malus pumila Mill.) and twenty of its sports by image analysis

Abstract

Fruit surface colour of the apple cultivar ‘Gala’ and 20 naturally occurring red colour mutants of ‘Gala’ was compared using digital image analysis. All the sports of ‘Gala’ gave higher percentages of red colour readings than ‘Gala’ itself. The breakdown of total red colour into light red, medium red, and dark red found differences between ‘Gala’ and its sports and between sports. A multiple allelic series at the loci governing red pigment production is proposed as the genetic mechanism controlling the expression of red coloration in ‘Gala’ apples.

Keywords:

• apples
• Malus pumila Mill.
• digital image analysis
• fruit colour
• ‘Gala’ apple
• colour sports
• genetics