Flavolans and Growth‐Promoting Catechins in Young Shoot Tips of Prunus Species and Hybrids

Young shoot tips of species and hybrids from the Prunus section eucerasus contain catechin, epicatechin and flavolans (oligomeric flavans including biflavans). Prunus avium shoot segments, 2 mm in length, were excised from the elongating zone of growing shoots and cultured in vitro on a liquid Murashige and Skoog medium containing indolyl‐3‐acetic acid and benzyl adenine. Supplementation of the same medium with (+)‐catechin and epicatechin resulted in apparent promotion of callus growth. This effect was greater under long day conditions than under continuous dark.