- Phenotypic variation in relatives of tomato. Some of this variation may be due to the effects of siRNAs (picture from Tanksley and McCouch Science 277 (1997) 1063-1066)
Many of the siRNA loci are associated with transposons and repeated sequence structures in the genome. These genetic elements are highly polymorphic between genotypes and exhibit significant variation between related species. It is conceivable that part of the phenotypic variation between related genotypes or species is due to the effects of these polymorphic siRNA loci. We are exploring this possibility in tomato with the aim of using siRNAs as markers in breeding programmes. It may also be possible to select for variation in small RNA loci or to manipulate the expression of these loci in order to achieve improvement in the crop.