Improved shoot multiplication of mature hazelnut (Corylus avellana L.) in vitro using glucose as a carbon source.

Shoot cultures established from mature trees of hazelnut (Corylus avellana L.) cvs. Nonpareil and Tonda Gentile Romana were used to determine the effects of basal media, carbon sources and concentrations, pH and cytokinins on shoot multiplication. All factors except pH affected the multiplication rate. Shoot multiplication was the best on a modified Driver and Kuniyuki medium for Paradox walnut (DKW) supplemented with 6-benzylaminopurine (BA) (1.5-3 mg/l). Plants grown on 3% glucose or fructose medium produced more and longer shoots than those on sucrose. The general appearance and growth habit of shoots were better on medium with glucose than fructose. 'Nonpareil' shoots elongated better than those of 'Tonda Gentile Romana.' Changes in medium pH from 4.7 to 5.7 did not significantly affect the multiplication rate. More than 10 genotypes propagated well on modified DKW medium with glucose. This is the first report of the effect of carbon sources on shoot multiplication of hazelnut and provides a basis for further research in the improvement of hazelnut micropropagation.