Genetic based resistance

Screening cultivars of red and other raspberries and wild Rubus species have identified potential sources of resistance. ‘Latham’ and ‘Winkler’s Sämling’ were identified early as having significant disease resistance, and species material such as R.strigosus (in the pedigree of Latham) and R. ursinus have been identified (Barritt et al., 1979). It has been speculated that these two sources are the same or genetically very similar. It has also been noted that the resistance in Latham has never broken down. The raspberry-blackberry hybrid cv. Tayberry, also demonstrates immunity to this disease (Duncan et al., 1987). However, none of the commercially important raspberry cultivars in Europe seem to have useful levels of resistance (Scherer and Riedel 1990).

Genetic resistance through plant breeding offers a feasible and effective method of control. However because of the difficulty in developing an accurate screening system and the time involved in the selection of resistant seedlings, then combining resistance with other desirable traits, for example fruit size and quality, breeding has not yet had the anticipated impact in commercial production. More research on the genetic basis of resistance and breeding is required as well as improved selection strategies.
Steps to the development of marker assisted breeding in raspberry for root rot resistance

The identification and utilisation of resistance from Latham would provide a genetic based strategy for control. Tackling the impact of root rot through a molecular breeding approach would offer a tool for a quick screen for the likelihood of resistance. The variety Latham derived from R. strigosus is one of the few sources of resistance and if resistance loci can be determined a marker assisted breeding approach can be used to more quickly introgress genetic based resistance into commercial varieties.

Field and glasshouse screening of progeny from the Glen Moy x Latham cross was carried out over three seasons. Plants were given a score on a one to five scale for root rot symptoms.

Figure 1: Field screening for resistance

Figure 1: Field screening for resistance.

Additionally for glasshouse grown plants root was assessed before and after the experiment to determine extent of damage. This data was used to identify map regions responsible for resistance to root rot and markers were identified for marker assisted breeding.

Figure 2: Glasshouse screening of Glen Moy x Latham cross for resistance

Figure 2: Glasshouse screening of Glen Moy x Latham cross for resistance.

Outcomes of the project

This work has identified germplasm with resistance to root rot, developed molecular markers for screening promising selections for resistance and produced an enhanced map for raspberry breeding.


Barritt, B.H., Crandall, P.C. and Bristow, P.R. 1979. Breeding for root rot resistance in red raspberry. Journal of the American Society for Horticultural Science 104, 92 – 94.

Duncan, J.M., Kennedy, D.M. and Seemüller, E. 1987. Identities and pathogenicities of Phytophthora spp. causing root rot of red raspberry. Plant Pathology 36, 276 – 289.

Scherer, W. von, and Riedel, M. 1990. Die Phytophthora-Wurzelfaule der Himbeere. Obstbau 10, 426 – 430.