| dc.description.abstract | Five isozyme systems, esterase (EST), glutamate
oxaloacetate transamlnase (GOT), malate dehydrogenase
(MDH), malic enzyme (ME) and peroxidase (PXD) were assayed
using embryos, calli, roots, cotyledons and leaves of Citrus
sinensis CV. "Valencia" and Citrus limon cv . "Rough
Lemon" by polyacrylamide gel electrophoresis. Ls ozyrne
profiles of these five enzyme systems were used to
dist ingui sh nucellar from zygotic genotypes of in vitro
produced seedlings. The frequency of zygotic seedlings
resulting from open-pollination was found to vary between
0.0% and 6. 3%. Embryo culture significantly enhanced the
recovery of zygotic seedlings in "Rough Lemon" hut not in
"Valencia". All, except, one, of 86 plantlets produced via
in vitro nucellar embryogenesis were found to be
genetically uniform. Tissue and age specific PXD isozyme
patterns were ·observed.
Isolation and culture of preformed embr-yos resulted
in the production of upto 13 and 9 seedlings per seed ln
"Valencia and "Rough Lemon", respectively. The use of
isozymes and tisspe culture as tools for the identification
of nucellar and zygQtic genotypes in polyembryonic Citrus
species is discussed. Isozymes can be used for the
preliminary identification of potential new genotypes
resulting from cross-pollination and tissue culture
manipulation. | en |
