Increasing total leaf alkaloid concentrations in periwinkle (Catharanthus roseus) by combining the macro-mutant traits of two induced leaf mutants (‘necrotic leaf’ and ‘nerium leaf’)

SummaryThe leaves of periwinkle (Catharanthus roseus) are a source of the highly-valued anti-cancer alkaloids, vincristine and vinblastine. Increasing the concentrations of leaf alkaloids is an important objective of research programmes on this species because of their high medicinal and commercial value and their naturally low concentrations in plants.Two ethyl methanesulphonate (EMS)-induced macro-mutants, ‘necrotic leaf’ and ‘nerium leaf’, with enhanced concentrations of total leaf and root alkaloids compared to their parental variety,‘Dhawal’, have been identified.These two mutants were crossed and double-mutant recombinants expressing both macro-mutant traits, ‘necrotic leaf’ and ‘nerium leaf’, were isolated from the F2 generation to determine the possibility of further increasing the concentration of total leaf alkaloids. Fourteen F5 generation double-mutant recombinant lines were evaluated along with the two parental macro-mutants and the original parental variety, ‘Dhawal’. The 14 double-mutant re...