fast versatile regeneration of trifolium alexandrinum l.
Abstract Trifolium alexandrinum L. (Egyptian clover) is
one of the most important forage crops in the world. Its
regeneration in tissue culture has been described in a few
reports but the efficiency, accurate time scales and applicability
to various genotypes of the described procedures are
uncertain. Therefore their suitability for genetic transformation
is unclear. In this study, were report new fast procedures
for regeneration of Egyptian clover that are
applicable to the regeneration of various genotypes (Mescawi-
ahaly, Sakha3 and Sakha4). Shoots were regenerated
from intact and wounded cotyledons as well as hypocotyls of
Mescawi-ahaly on naphthaleneacetic acid/benzyladenine
(NAA/BA) and naphthaleneacetic acid/thidiazuron (NAA/
TDZ) media. The highest shoot regeneration frequencies
were obtained from intact cotyledons on NAA/BA
(0.05 mg l-1 NAA combined with 2.0 mg l-1 BA) and
NAA/TDZ (0.05 mg l-1 NAA combined with 1.0 mg l-1
TDZ) media (66.2 and 43.1% respectively) compared to
18.4 and 10.1% for wounded cotyledons on NAA/BA and
NAA/TDZ respectively. 21.0% shoot regeneration frequency
was observed for hypocotyls on NAA/BA
(2.0 mg l-1 NAA combined with 0.5 mg l-1 BA) medium
but no regeneration was obtained on NAA/TDZ medium.
Rooting of the regenerated shoots was induced on indole
butyric acid (IBA: 0.24 mg l-1) orNAA(2.0 mg l-1) media
where IBA medium supported significantly higher frequencies
of rooting as well as survival of the whole plantlets
after transfer to soil. However, the rooting and survival
frequencies also depended on the type of explant and the
medium used for shoot regeneration. The two cultivars