Susceptibility of Solanum curtilobum to Spongospora subterranea (Wallr.) Johnson

IT has been stated by Dorojkin 1 that Solanum curtilobum and eight other South American species and varieties of Solanum are immune from Spongospora subterranea , the causal agent of powdery scab of potatoes; in this paper the number 8008 is linked with S. curtilobum , as are other numbers with the other Solanum species, and these are presumably the reference numbers of individual lines which were being used. Bukasov 2 quotes Dorojkin and states that immunity from powdery scab has been established in S. curtilobum and the eight other species and varieties. This statement has been repeated by Hawkes 3 and Black 4 , but in these papers no mention is made of the reference numbers of the individual lines concerned. It might be assumed, therefore, that S. curtilobum as such is immune, despite the fact that many lines or varieties of this species exist. That some of these lines at least do not carry immunity was shown by the following experiments.