EFFECTS OF AUXIN AND LIGHT TREATMENTS OF DONOR PLANTS ON SHOOT PRODUCTION FROM INDICA-TYPE RICE (ORYZA-SATIVA L.)

An efficient clonal propagation procedure for a Brazilian indica rice subspecies was developed with shoot apex: explants. Shoot apices were excised from 4-d-old seedlings and cultured on MS medium supplemented with 8.9 mu M 6-benzyladenine. The efficiency of shoot production was influenced by growth regulators and light treatments to the donor plan t. Explants derived from seedlings grown in the presence of 10.7 mu M naphthaleneacetic acid and in the absence of light showed significantl y increased regeneration capacity as compared to control explants. Ana tomical analysis of the new shoot meristems revealed that they origina ted from preexisting apical and axillary meristem as well as from the mesocotyl parenchyma.