|Fast Track Fruit Breeding|
Appalachian Fruit Research Station Genetic Enhancement of Fruit Crops Research Unit
FasTrack Breeding Initiative
The American tree fruit industry is facing challenges of climate change, reductions in available labor, global competition, the need for reduced chemical inputs, the spread of exotic pests and pathogens, and consumer demands for enhanced fruit quality. To meet these challenges the development of improved varieties is more vital than ever. Yet, fruit tree breeding remains a slow, arduous process that has changed little over the centuries. Fruit tree breeding limitations include: a) protracted generation cycles, that is, the time between seed planting and fruiting which can last from 3 to 20 years depending on the fruit crop; b) the large land areas necessary for planting seedling fruit tree populations and the associated expenses of field operations; and c) the fact that flowering occurs only once each year and is dependent upon sufficient chill in the winter and warmth in the spring.
Genomics research aimed at improving tree fruit breeding has focused on marker-assisted selection (MAS); that is the association of pieces of DNA with fruit characteristics of interest. In this case selection for certain characteristics can be made at the DNA level. However, as with classical fruit breeding, the improvement to fruit tree breeding offered by this biotech strategy is still limited by the inherently slow generation cycles of fruit trees. To address this need, a technology to shorten the breeding cycle is required.
Using the European plum (Prunus domestica) also known as the “domestica” or “prune” plum we demonstrate that not only can the generation cycle be dramatically shortened but that we can overcome the environmental limitations of winter chilling on flowering and produce fruit year-round. We have achieved this by incorporating into plum trees a gene from poplar, a forest tree, which induces the plum trees to flower early and continually and to produce fruits with viable seeds within one year versus the normal 3-7 years.
We are using this early flowering gene for the development of a breeding strategy that we call ‘FasTrack’ breeding. Instead of the field, ‘FasTrack’ breeding can be carried out in a greenhouse. Through the ‘FasTrack’ breeding method we plan to rapidly incorporate improved traits into plum and to develop improved breeding stock and new varieties in a fraction of the time that would be required for conventional breeding.
It is interesting to note that while ‘FasTrack’ utilizes genetic engineering to speed the breeding process, the breeding stock and varieties produced from ‘FasTrack’ breeding will not be genetically engineered.
For a more detailed look at the ‘FasTrack’ breeding method please view the accompanying Power Point presentation on ‘FasTrack’ Breeding.