DIVERSITY OF SESQUITERPENES IN 46 POTATO CULTIVARS AND BREEDING SELECTIONS

Rishitin, lubimin, and solavetivone were the major sesquiterpenes found in 46 cultivars and breeding selections of potato (Solanum tuberosum L.). Concentrations of total sesquiterpenes were low or undetectable in untreated tuber slices, but ranged from 5 to 101 mu g/g of fresh weight 4 days after treatment with the elicitor arachidonic acid. Seven genotypes produced significantly (P < 0.01) higher sesquiterpene concentrations than Russet Burbank (17 mu g/g), a widely grown commercial cultivar. More than half of the genotypes tested were significantly (P < 0.01) different from Russet Burbank in sesquiterpene composition due to higher ratios of lubimin or solavetivone, both of which are reported to be biosynthetic precursors of rishitin. The highest ratios of solavetivone to total sesquiterpenes were strongly correlated with derivation from S. tuberosum ssp. andigena CPC 1673, which confers the H1 gene for resistance to the golden nematode (Globodera rostochiensis).