Anthers of L-680A', `Licato', and `Ailsa Craig' tomato (Lycopersicon esculentum Mill.) were plated on Doy's basal medium 1 to determine whether microspore developmental stage and anther length influence anther callus production. Although calli were induced at all stages of anther development, anthers containing prophase I-stage microspores produced the highest frequency of calli. Fewer calli were produced as microspores approached the uninucleate and binucleate pollen stage. Callus diameter also decreased as anther development progressed. Significantly larger calli were produced from prophase I than later-stage anthers. Time of anther harvest (morning vs. afternoon) did not significantly affect callus number or diameter. Anther and flower bud length both were significantly correlated with anther developmental stage, the number of anthers producing calli, and mean calli diameter. In each case, anther length exhibited a significantly better correlation than bud length.

No abstract

No 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). -

Anthers from. three tomato cultivars, `L-680A', `Ailsa Craig', and `Licato', were plated on DBM1 medium solidified with one of four solidifying agents, Bacto-agar, Gelrite, Noble agar, or Phytagar, to evaluate their ability to promote initiation and growth of tomato anther callus. The optimum concentration of each solidifying agent was compared with a liquid control. Optimum levels of the various solidifying agents were (in g·liter-1) Phytagar, 5; Gelrite, 3; Noble agar, 6 and Bacto-agar, 8. Both the number and diameter of calluses were affected by type of solidifying agent and anther genotype. Significant interactions were also found between tomato cultivars and solidifying agent. Noble agar produced good results with `L-680A' and `Ailsa Craig', but not with `Licato'. Bacto-agar reduced the number and size of callus by 38% when compared with the liquid treatment and by 42% when compared with the best agar treatment (Noble agar).