ABSCISIC-ACID AND ANCYMIDOL PROMOTE CONVERSION OF SOMATIC EMBRYOS TO PLANTLETS AND SECONDARY EMBRYOGENESIS IN ASPARAGUS-OFFICINALIS L

The effects of abscisic acid (ABA) (0, 0.09 mu M, 0.19 mu M, 0.28 mu M , and 0.38 mu M) or ancymidol (0, 0.98 mu M, 1.95 mu M, 2.93 mu M, 3.9 0 mu M) in embryo germination medium on the conversion of primary embr yos to plantlets and secondary embryogenesis were evaluated for aspara gus. ABA and ancymidol each significantly enhanced both responses. ABA was more effective than ancymidol in promoting the conversion of prim ary embryos to plantlets, while the converse was true for the producti on of secondary embryos. The most effective treatments for embryo conv ersion were 0.19 and 0.28 mu M ABA; 75-77% bipolar and 55-57% globular embryos converted to plantlets. For secondary embryogenesis, the most effective treatments were 1.95 and 2.93 mu M ancymidol; 99-101 and 84 -86 somatic embryos were produced from 10 globular and 10 bipolar embr yos, respectively. Bipolar embryos generally converted to plantlets be tter than globular embryos, but more secondary embryos were produced f rom globular embryos than from bipolar embryos in all treatments. ABA and ancymidol also affected the morphology of the plantlets produced. The plantlets from the embryos incubated on the medium with ancymidol had strong and thick shoots and roots, while those on the medium with ABA had long, thin shoots and short, thin roots.