INFLUENCE OF PLANT-GROWTH REGULATORS, POLYAMINES AND GLYCEROL INTERACTION ON GROWTH AND MORPHOGENESIS OF CARPOSPORELINGS OF GRATELOUPIA CULTURED IN-VITRO

The influence of the plant growth regulators 2,4-D, GA(3), BA and kine tin, and the polyamines putrescine, spermidine and spermine were teste d on axenic in vitro cultures of carposporelings of Grateloupia doryph ora. The auxin 2,4-D (10(-3) M) and the polyamine spermine (10(-6) M a nd 10(-3) M) induced a callus (disorganised cell mass that arose from the organised tissue of the carposporeling, as demonstrated by microsc opic monitoring of the tissue). Putrescine and spermidine (10(-3) M) t ransformed the carposporelings into cell masses that produced shoots. BA (10(-3) M) and kinetin (10(-6) M and 10(-3) M) were inhibitory. In 10(-1) M glycerol-containing culture medium, which is known to induce the formation of morphogenic cell masses, the addition of GA(3) M) res ulted in the inhibition of the morphogenesis (i.e. shoot emission) in the cell mass. The kinetin at 10(-6) M inhibited morphogenesis, whilst at 10(-3) M inhibited even the formation of the cell masses. The comb ination of glycerol (10(-1) M) and the auxin 2,4-D (10(-6) and 10(-3) M) or the polyamines putrescine, spermidine and spermine (10(-6) and 1 0(-3) M) resulted in a bigger size of the cell masses that led to a hi gher amount of shoots per cell mass than in glycerol alone.