Increased root and shoot production during micropropagation of cherry and apple rootstocks: Effect of subculture frequency

Abstract

Shoot cultures of apple rootstock cv. M9 and cherry rootstock cv. F12/1 were established and then divided into several sublines that were subcultured at 28-42-day intervals. Consequently, similarly aged cultures received various numbers of subcultures. Cultures kept at 24 °C showed an increase in shoot and root production over time. There were differences in shoot and root production between apple lines, but there were no differences among sublines. In cherry, altering the subculture interval affected rooting competence, which increased with time. Cherry cultures maintained at 4 °C gave rise to cultures that were as easy to root as cultures kept at 24 °C with more frequent subculturing. We conclude that total time in culture is the most important factor bringing about physiological changes in these genotypes of micropropagated apple and cherry.