This research was carried out during two seasons 2014 – 2015 to study effect of seed
coats on germination of endocarp, seed and embryos of two wild genotypes (M1, M2) of
Mahaleb rootstock (Prunus mahaleb L.) prevailing in Alhaffa area, Lattakia. Th
e
experiments were done at Lattakia Scientific Agricultural Research center and Faculty of
Agriculture at Tishreen University.
The Results of the seeds planted on agar 0.7% in dark at 15 C° showed that no
germination of the M1 endocarp VS late and low germination at 10% for the M2 endocarp
starting after 98 days. As for seeds, the germination was (66.66%) and (53.33%) for M1
and M2, respectively. Removal of the woody coat (endocarp) and seed coat makes the
germination faster. the embryos germination was (80%) and (60%) for M1 and M2,
respectively.
Experiment was conducted on 160 fertilized egg sterile, distributed
in four groups of 40 eggs in each of them, eggs incubation in the
hatchery for 12 h, and then go out and inject eggs experimental
Groups (1-2-3) with a solution of tetracycline under the embryo disk.
Thirteen viable and post - frozenthawed Shami cows embryos obtained by
super-ovulation and artificial insemination technique in order to determine sex
of embryos. Biopsies (1-2 cells) of embryos at morula or blastocyst stage were
taken using micro
manipulation under inverted microscope.
It was concluded that aspiration
of 1-2 blastomere (s) from embryos at morula or blastocyst stage was enough to
determine sex of embryo using PCR and it is recommended that using this
technique can be a useful tool in splitting and transferring of desired sex
embryos in genetic improvement program.
Pregnant mothers were irradiated by a single dose of gamma rays
(٠،٢،٤،٦ Gy, Cobalt ٦٠) in the days ١٠،١٢،١٤،١٦،١٨ of pregnancy. The
heads of the embryos’, and those of the neonates were taken at
consecutive intervals of irradiation, starting from
١٦ days of pregnancy
till ٣rd day after delivery. The effect of irradiation was investigated in the
development of the ٢nd and ٣rd lower molars on serial tissue sections,
within consecutive periods of their organogenesis. Irradiation led to
growth-deficiency in the ٢nd & ٣rd molars, and caused delay in their
development. This was observed in various degrees depending on the
dose, time of irradiation, and time after irradiation.
Mice embryos were irradiated in utero by gamma rays (٠،٢،٤،٦ Gy) at
١٠،١٢،١٤،١٦،١٨ days of gestation. Histological study was carried out on the
first premandibular molar after ٢،٤،٦،٨ days of irradiation, to investigate the
effect of irradiation on different stages of molar development.
This study involved the irradiation of mouse embryos at different stages of
pregnancy, using dose of ٤ Gy γ-radiation, at ١٠, ١٢, ١٤ and ١٦ days of
pregnancy. Pregnant mice were killed after ٢, ٤ and ٦ days post irradiation.
Embryo’s heads were is
olated and serial cross sections were made to
investigate the effect of irradiation on the different components of the eye at
different periods of eye organogenesis.
It was proved from this study that irradiation causes microphtalmia and
decrease in the growth of lens, retina and corneal stroma, as well severe
disruption in its development and disfigurement in its hitogenesis. These
defects have shown great differences in their severity according to the age of
embryos at exposure and the number of days post irradiation.
