PLANTLET REGENERATION FROM CALLUS AND PARENT TISSUE IN ORNITHOGALUM-THYRSOIDES

Pieces of stem, leaf, ovary, sepals, and bulb scale of Ornithogalum all gave rise to adventitious plantlets when placed on basic Murashige and Skoog medium containing no added growth hormones. When one of the auxins, IAA, .alpha.-naphthaleneacetic acid (NAA), or 2,4-D were added to the medium, stem and leaf gave rise to callus from which plantlets could be recovered by transfer to low auxin medium or basic medium. Plants derived from parent tissue were diploid (2n = 12). Plants derived from NAA callus were at first diploid, but during seven 5-wk passages on NAA medium an increasing proportion of tetraploid plants, up to 50% or more, were produced while the number of plantlets recovered from the same amount of callus declined.