PRI disease resistant apple breeding program

[3] L. Fredric Hough, then a graduate student at the University of Illinois, studied Crandall's work.

Hough published a paper in 1944, leading to a 1945 collaboration with Purdue University pathologist J. Ralph Shay.

[2] The modified backcross breeding strategy used cultivated apple with recurrent parents from selected susceptible members of the wild ancestral genus malus.

Several Malus species were screened and utilized to incorporate their resistance factors into the more advanced pomological backgrounds.

[2] By 2000, the PRI have already released a total of eighteen apple cultivars, containing the scab-resistant Vf gene derived from Malus floribunda 821.

Pristine apple , is one of the scab -resistant cultivars, to be developed by "PRI", hence its name "PRI"stine.