Study of morphological trait changes in in-vitro plantlets of three olive cultivars (‘Dezful Baghmalek’, ‘Dezful Safiabad’ and ‘Roughani’) domesticated in Iran

Abstract

Somaclonal variation of three Iranian olive cultivars, 'Dezful Baghmalek' (DB), 'Dezful Safiabad' (DS) and 'Roughani' (R), during long-term propagation was evaluated over seven subcultures. Morphological traits such as leaf length and width, number of leaves per shoot, shoot length, internode distance and rooting percentage were measured. Our results showed that DB showed greater somaclonal variation than DS and R, especially in rooting percentage and root length; R showed steady behavior, especially in leaf length and width, root length, leaf number and rooting percentage over several subcultures. Although fluctuations were observed in all traits, the most significant trait studied with almost similar variation in the three cultivars was the number of branches. Overall, we could not select a specific subculture period for creation of optimal morphological changes, because increase in leaf length and width for R was best in the second subculture, whereas, for DS, it was optimal in the seventh subculture. In order to achieve morphological changes in length of shoots and number of leaves and to enhance rooting percentage in cultivar R and also internode distance in cultivar DS, somaclonal variation over several subcultures will be appropriate.