GROWTH CHARACTERISTICS OF CALLUS FROM LAMINA AND BUD REGENERATION ABILITY IN LETTUCE (LACTUCA SATIVA L.)

The transplant production techniques in tissue culture has a lot of possibilities for mass propagation of useful cultivar. But, it does not almost apply to practical agriculture, because of unestablishment of controlling plant regeneration from callus. If the selection of callus being competent for regeneration were possible, the efficiency of transplant production in tissue culture would rise remarkably.

In order to resolve these problems, quantitative evaluation of callus growth is necessary at first. We have, therefore, invented the original culture method of callus that is able to be evaluated quantitatively. We called the callus a particle of callus. By using a particle of callus, propagation and bud regeneration of callus were investigated. In conclusion, the growth characteristics of callus was dependent on lamina as culture material. It became clear that the calli formed for short period had high regeneration abilities.

In the cultivar of lettuce with red pigment on leaf, we have developed a culture method that induces bud regeneration efficiently by red pigmentation on callus. We have made sure that utilizing the callus with red pigment lead to the remarkable increase of the efficiency of transplant production in tissue culture.