Seed-based in vitro propagation to accelerate variety development

To shorten the current lengthy selection process in sugarcane breeding and to accelerate genetic gain, Sugar Research Australia is implementing a range of novel breeding strategies and selection tactics. One strategy is to rapidly evaluate the progeny of elite crosses in replicated trials without passing through the traditional Stage 1 trials. However, insufficient planting material hinders its adoption. A seed-based in vitro propagation system has been developed for sugarcane in which sodium hypochlorite (bleach) and plant preservative mixture (PPM TM ) were used in the sterilisation of seeds and seedlings, as well as in the treatment of infected seedlings. The system had been successfully implemented to propagate over 1000 clones of the elite cross Q208 A x CP74-2005, for a Stage 2 selection trial. The new system, a first for sugarcane, is more cost efficient, providing three times the number of clones as in the seedling-based micropropagation system with the same input of resources. This innovation will shorten the selection cycle of proven elite crosses by up to 3 years, accelerating the delivery of new varieties. Key words In vitro propagation, seed, breeding