(2) Genotypic types of resistance A. Vertical resistance垂直抗病性 a variety is particularly resistant to one or some specific races of pathogens while it is highly susceptible to other races. Race specific resistance: single genes, oligo-genes Small environmental Influence: Non-durable resistance Incidence Race a e(2) Genotypic types of Resistance A. Vertical Resistance 垂直抗病性 A variety is particularly resistant to one or some specific races of pathogens while it is highly susceptible to other races. Race specific resistance: single genes, oligo-genes Small environmental Influence; Non-durable resistance Race a b c d e f Incidence %