POSSIBLE REASONS OF ONE-WAY VARIATION IN GLOBE ARTICHOKE

Variations observed in ‘Sakız’ which is early variety of artichoke in Turkey is the main subject of this research. Leaf lobulation and loss of earliness are good parameters for distinguishing ‘Sakız’ type plants from the varied ones. Previous observations showed that GA₃ application to the varied plants restored the leaf properties and early yield. In this research, it was aimed at testing the possible role of GA₃ on this variation. GA₃ was applied to the varied plants grown in vivo and in vitro. Leaf and yield properties, number and size of stomata, number of chloroplast in stomata guard cells and chromosome number were assessed. It was also tested whether bud positions on the underground stem are effective to this variation or not. As a result, it was found that GA₃ could be effective in controlling this variation through the mean of all the parameters except chromosome number. On the other hand, it was assessed that there were significant differences between the ploidy levels of both groups of plant. Chromosome numbers in the ‘Sakız’ and varied one are determined as 2n=14 and 2n=28, respectively. Another result obtained is the effect of bud positions on the underground stem. It was determined that offshoots generated from the buds, localised on the lower part of underground stem were mostly of the ‘Sakız’ type.