Early-season replacement for Imperial mandarin (CT09014)

What was it all about?

The early-season mandarin market in Australia is dominated by Imperial mandarin, an old variety that is popular with consumers but has characteristics that cause problems including…

• Granulation in some seasons when consistent quality is a major factor for the supermarket trade
• The soft, thin skin makes it less suitable for export
• It rates poorly on many traits desired by export markets, such as colour, juice content and sugar content.

While research is under way to solve these quality problems with Imperial, this project supported a breeding program to find better varieties for the early part of the mandarin season, run from 2009 to 2013.

All germplasm held in two collections, the Bundaberg Research Facility and Plant and Food NZ was reviewed to identify traits for early-season breeding. Each July a crossing program was decided and, over the five flowering seasons, more than 18,500 individual pollinations were carried out using more than 90 different parents.

Disease screening for susceptibility to Alternaria brown spot ruled out more than a third of the hybrids prior to field planting.

At the end of the project, more than 15,000 new hybrid trees with a diverse range of parents were growing in orchards in the Bundaberg facility. The population is now available as a resource for the selection of good quality early-season genotypes that may out-perform existing varieties.