REGENERATION OF GARLIC PLANTS (ALLIUM-SATIVUM L, CV CHONAN) VIA CELL-CULTURE IN LIQUID-MEDIUM

Aiming at the genetic improvement of garlic cultivars, a cell suspension protocol was established which includes the induction of friable callus, establishment of cells in liquid medium, plating, regeneration, and bulb formation. Calluses of various textures from compact to friable and from green to yellowish were obtained by culturing explants excised from inner leaves of garlic bulbs on Marashig-Shoog (MS) medium with 2,4 dichlorophenoxy acetic acid (2,4-D), (1.1 mg/liter [5.0 mu M]), picloram (1.2 mg/liter [5.0 mu M]), and kinetin (2.1 mg/liter [10 mu M]). Friable callus occurred on MS-A contained 2,4-D alone (1.0 mg/liter [4.52 mu M]) and this callus was used to develop cell suspension cultures, which were maintained in liquid MS-B medium with a 2,4-D/benzyl adenine (BA) (0.5 mg/liter [2.25 mu M]: 0.5 mg/liter [2.22 mu M]) ratio. High plating efficiency was obtained on MS-C medium with different naphthalene acetic acid/BA combinations. Regeneration occurred after transfer of the caulogenic mass to MS-C medium containing 10 mg/liter (74.02 mu M) and 20 mg/liter (148.04 mu M) adenine for 60 days, followed by transfer to adenine-free medium. Plantlets transplanted to soil showed normal phenology. Shoots grown on modified MS medium supplemented with indolylbutryic acid (3.0 mg/liter [14.7 mu M]) stimulated bulb formation by 30 days in culture.30P315015

Efficient Regeneration of Eucalyptus urophylla x Eucalyptus grandis from Stem Segment

The aim of the present study was to establish an efficient regeneration system for the hybrid E. urophylla x E. grandis by means of organogenesis. Stem segments from seedlings were used as explants and cultured in a modified Murashige and Skoog medium (MS), supplemented with 13.2 µM N-phenyl-N'-[6-(2-chlorobenzothiazol)-yl] urea (PBU) and 0.285 µM indole-3-acetic acid (IAA). PBU was a useful growth regulator. After cultivating for 5 d, 96% explants formed callus. After 30 d, the calli obtained were transferred to MS medium containing different combinations of 6-benzyladenine (BA) and naphthalene acetic acid (NAA). Compared with other growth regulator combinations, PBU stimulated more vigorous calli and restrained browning. In addition, a large percentage (91.3%) of the calli induced by PBU showed adventitious buds formation. Shoot elongation was then stimulated on half-strength MS mineral salts medium supplemented with 6.6 µM PBU and 0.285 µM IAA for 20 d. For rooting, the elongated shoots were cultivated on root induction medium containing 2.46 µM indole-3-butyric acid (IBA). Plantlets were then successfully transplanted to a greenhouse. This procedure represented an efficient way of E. urophylla x E. grandis plant regeneration