Apple trees do not reproduce true-to-type form seeds. Instead, desirable cultivars are propagated by grafting vegetative material onto suitable rootstocks. Rootstocks can alter scion traits of importance to agriculture, including fruit size, flowering precocity, drought tolerance, disease resistance, cold tolerance, and tree stature. In effect, the traits of genetically identical apple cultivar scions can be very different depending on the rootstock to which they are grafted. Our study harnesses the phenomenon to identify genes in apple which are involved in controlling agriculturally important traits. The central hypothesis driving this research is that scions grafted to different rootstocks have different overall patterns to gene expression, and that these differences in gene activity play a role in determining the phenotypic differences between trees.

 

This project is funded by the National Science Foundation's Plant Genome Research Program as Award number 0420394