Tomatoes are often produced commercially from grafted plants; we are aiming to identify genes and genetic variation that could be used to breed improved rootstocks.

Tomatoes, peppers, melons and cucumbers are produced predominantly as grafts between rootstock and scion cultivars, and the rootstock genotype is chosen to manage crop vigour and resistance to root diseases and abiotic stresses. However, the genetic basis for these root traits is poorly understood, making breeding for these traits difficult and slow.

This ‘Stand-alone’ LINK project, known as RootLINK, is genetically fine-mapping specific locations on tomato chromosomes that can influence root characteristics using next generation sequencing and high throughput genotyping platforms; this will ultimately provide tools to rootstock breeders. RootLINK is also investigating the mechanisms by which rootstock genotypes influence the growth and physiology of the shoot.

Tomato plants roots

Progress update

We have characterised a chromosomal location in tomatoes that influences root vigour and ability to penetrate compacted soil. We have genetically mapped the locus to an interval of eight genes containing a clear candidate gene. We have obtained map positions for classical root mutations aerial root and bushy root and are characterising a novel mutant that affects tomato root meristem growth.