Evaluation of resistance of apple cultivars to Venturia inaequalis

Spreading inoculation is confirmed as the best inoculation method for Venturia inaequalis among the spreading, soaking, fungi disk coverage and injecting methods with conidiospore suspension of V. inaequalis.15 apple cultivars including“Qinguan”（Malus domestica）,“Fuji” （M. domestica）,“Gala” （M. domestica）,“Starking Delicious”（M. domestica）,“Jonagold”（M. domestica）,“Pink Lady”（M. domestica）,“Gold Century”（M. domestica）,“Gafu”（M. domestica）,“Pacific Rosa”（M. domestica）,“Granny Smith”（M. domestica）,“4-1” （M. pumila）,“M26”（M. pumila）,“MM106”（M. pumila）,“Midget Crabapple”（M. micromalus）and“Xinjiang Wild Apple”(M. sieversii) were collected. Resistance of the 15 cultivars to V. inaequalis was determined through conidiospore suspension inoculation. The 15 cultivars were divided into 4 groups based on disease resistance index and average disease severity. The divisions are high resistance cultivars including “Xinjiang Wild Apple” and “Qinguan”; moderate resistance cultivar including “Midget Crabapple”; moderate susceptible cultivars including “MM106”, “M26”, “Jonagold”, “Starking Delicious”, “Fuji” and “Gala”; and high susceptible cultivars including “Granny Smith”, “4-1”, “Gafu”, “Pacific Rosa”, “Pink Lady” and “Gold Century”.