Dark–Light Treatments Influence Induction of Tomato Anther Callus

Abstract

Three tomato (Lycopersicon esculentum Mill.) cultivars were studied to determine the effect of nine dark-light regimes on anther callus initiation and growth. Prophase I (leptotene) stage anthers of `L-680A', `Licato', and `Ailsa Craig' were plated on Doy's basal medium 1 and provided with 2 to 10 weeks of dark treatment. After each dark period, each plate was transferred to a 16-hour photoperiod for the duration of the 10-week experiment. At this time, the number of anthers producing calli and the diameter of the calli produced were recorded. Callus number and diameter increased as the dark period duration increased. Callus diameter peaked at 8 weeks of dark treatment for `Ailsa Craig' and `Licato', whereas `L-680A' calli continued to grow over the entire 10-week dark treatment. Although the number and size of callus may continue to increase past 8 weeks of dark incubation, callus quality and appearance decreased noticeably during this period. For each additional week of dark period exposure, 7% more of the plated anthers produce callus, and callus diameter increases by 0.27 mm (12% of total growth). -