Red raspberry (Rubus idaeus) is a good species for the application of such techniques, being diploid (2n = 2x = 14) with a very small genome (275 Mbp). The availability of abundant genetic variation in natural and experimental populations and adaptation to a range of diverse habitats (Graham et al. 1997b; Marshall et al. 2001; Graham et al. 2003) offers researchers a rich source of germplasm to increase variation in morphology, anatomy, physiology, phenology and response to a range of biotic and abiotic stresses. This coupled with the application of more knowledge-based breeding should secure raspberry breeding in a changing climate and allow introgression of species material in a shorter timescale.

An evolving genetic linkage map of raspberry is available (Graham et al. 2004, 2006;2015, 2018, 2022, Hackett et al., 2018). This map was constructed utilising a cross between the phenotypically diverse European red raspberry cultivar Glen Moy and the North American cultivar Latham. This cross produced a segregation population of 323 individuals. Latham was one of the first cultivars to be produced through controlled breeding in the 1930s, and is estimated to be approximately 60% genetically similar to Glen Moy (Graham and McNicol 1995). Latham is a hardy, spiny-brown caned plant producing small fruits and is resistant to raspberry root rot. Glen Moy was produced in 1981, has large fruits, is spine free, green-caned, susceptible to low temperature damage and has no resistance to root rot.

The progeny of this cross segregate for root rot resistance as well as a broad number of other characteristics including pest resistance, crop architecture and fruit quality, which can be phenotyped and placed onto the linkage map. This provides, for the first time in raspberry, an unequalled resource for mapping both single gene and polygenic traits and developing diagnostic markers for the ones of premium value. In this instance, resistance to raspberry root rot will be targeted.

As an illustration of the practical utility of genetic linkage maps in raspberry, a study on Gene H is discussed. Gene H, the gene responsible for cane pubescence, had been reported for some time to be associated with resistance to cane botrytis and spur blight as well as susceptibility to rust and cane spot. With the availability of the raspberry genetic linkage map, it was possible to map Gene H, and to also map resistance to the four diseases with reported association. This work confirmed the association between Gene H and cane botrytis and spur blight but not with rust and cane spot (Graham et al., 2006).

With the demonstration of the linkage between Gene H and resistance to cane botrytis and spur blight, the gene itself can be used as a marker to predict resistance status for these two important diseases (Graham et al., 2006). The map has confirmed for two diseases, the close association with Gene H. This information has been transferred to breeders and cane morphology as determined by alleles for Gene H, provides an accurate prediction of disease resistance.


  • Graham, J. and McNicol, R.J. 1995. An examination of the ability of RAPD markers to determine the relationships within and between Rubus species. Theoretical and Applied Genetics 90, 1128 – 1132.
  • Graham, J., Squire, G.R., Marshall, B. and Harrison, R.E. 1997. Spatially dependent genetic diversity within and between colonies of wild raspberry Rubus idaeus detected using RAPD markers. Molecular Ecology 6, 1001 – 1008.
  • Graham, J., Marshall, B. and Squire, G.R. 2003. Genetic differentiation over a spatial environmental gradient in wild Rubus idaeus populations. New Phytologist 157, 667 – 675.
  • Graham, J., Smith, K., Mackenzie, K., Jorgensen, L., Hackett, C.A. and Powell, W. 2004. The construction of a genetic linkage map of red raspberry (Rubus idaeus subsp. idaeus) based on AFLPs, genomic-SSR and EST-SSR markers. Theoretical and Applied Genetics 109, 740 – 749.
  • Graham, J., Smith, K., Tierney, I., Mackenzie, K. and Hackett, C. 2006. Mapping gene H controlling cane pubescence in raspberry and its association with resistance to cane botyritis and spur blight, rust and cane spot. Theoretical and Applied Genetics 112, 818 – 831.
  • Kassim, A., Poette, J., Paterson, A., Zait, D., McCallum, S., Woodhead, M., Smith, K., Hackett, C. and Graham, J. 2008. Environmental and seasonal influences on red raspberry anthocyanin antioxidant contents and identification of QTL. Molecular Nutrition and Food Research (in press).
  • Marshall, B., Harrison, R.E., Graham, J., McNicol, J., Wright, G.M. and Squire, G.R. 2001. Spatial trends of phenotypic diversity between colonies of wild raspberry Rubus idaeus. New Phytologist 151, 671 – 682.