Variation occurring after natural and in vitro multiplication of early Mediterranean cultivars of globe artichoke (Cynara scolymus L)

Abstract

This study describes 3 variants: pastel, bull and pastel-bull. They appear after natural and in vitro multiplication of early Mediterranean cultivars of the globe artichoke. The rates of their occurrence were evaluated in Violet de Provence and in some other early cultivars. During micropropagation, the frequency of the pastel plants rose when the subculture number increased, sometimes reaching 100%. As these late bolting plants are undesirable, the practical use of micropropagation is restricted. Analysis of the nature of these variants showed that the bull variant is a tetraploid form issued from the normal type. The pastel-bull variant is a diploid-tetraploid chimeral form issued from the pastel type. The differences between the pastel and the normal type have not been explained. Their seed progenies were alike, with the deeply divided leaves of the pastel type. The entire leaf shape, which is a specific characteristic of the normal type of the early Mediterranean cultivars, was not transmitted by seed. © 1993.