| Abstract: | Field resistance to late blight in hybrid derivatives of the wild speciesSolanum demissum is a complex character, controlled by many different genetic factors and inherited in polygenic fashion. In the course of hybridization and backcrossing to commercial varieties to improve yield and other economic qualities, these factors become dispersed with consequent reduction in degree of resistance. By intercrossing appropriate selections the resistance factors may be reassembled and field resistance built up in varieties of commercial standard to a level high enough to make protective spraying unnecessary. |
