Tools and techniques to carry out the successive steps in the development of CPB resistant varieties are available (steps in wide arrows, tools in the boxes below the arrow). Several technologies can be used to solve the constraints related to the introgression of the resistance traits into the cultivated potato, notably to solve crossing barriers and to facilitate backcrossing using markers. Apart from classical breeding techniques, resistant varieties may also be obtained through genetic modification (e.g. by using resistant genes from other sources or by RNAi approaches targeting essential genes of the CPB)