Shoot Development in Established Callus Cultures of Cultivated Tomato (Lycopersicon esculentumMill.)

Abstract

Summary Four established callus lines of Lycopersicon esculentum Mill . and one of L. pimpinellifolium Mill ., ranging in age between 17 and 28 months, were grown on media containing various combinations of cytokinins (Z, BA, and 2ip) and IAA in an effort to induce shoot development. With all 3 cytokinins shoots formed only in one genotype, VFNT Cherry, and only after several months of regular transfers to fresh medium. When callus from plated suspension cultures derived from the 5 callus lines was grown on medium containing Z and IAA, shoots developed only from the VFNT Cherry callus. Four 4-month old callus lines of L. esculentum were also tested and VFNT Cherry was still the only genotype to produce shoots. The shoots produced by the 4-month old VFNT Cherry callus were normal in appearance and rooted readily. All shoots produced by the older cultures were morphologically abnormal and could not be induced to root.