M. Sevestrerigouzzo et al., GENETIC DIVERSITY AND ALKALOID PRODUCTION IN CATHARANTHUS-ROSEUS, C-TRICHOPHYLLUS AND THEIR HYBRIDS, Euphytica, 66(1-2), 1993, pp. 151-159
Inter and intraspecific variation was analyzed in two Catharanthus spe
cies with regard to isozyme polymorphism and indole alkaloid content i
n roots and leaves. No significant differences in alkaloid production
were observed in three groups of C. roseus plants individualized for t
heir flower color. Conversely, comparisons between C. trichophyllus an
d C. roseus, showed large differences of alkaloid profiles in both roo
ts and leaves. Specific isozyme markers on four presumed loci were fou
nd allowing us to establish that natural hybridizations could occur be
tween the two species when grown together. Experimental hybridizations
confirmed that introgressions were feasible but suggested that a repr
oductive barrier was acting and involved interspecific incompatibility
. The identification and assay of the main alkaloid compounds in natur
al interspecific hybrids displayed such a high hybrid vigor that inter
specific hybridization may present a new and successful way of improvi
ng alkaloid production in Catharanthus species.