The aim of this work is to study the factors affecting the in vitro propagation and developing of laboratory
system to obtain a higher mass production of such important plants of the Egyptian desert. This study conducted
on Quince (Cydonia oblonga Mill.) and Hawthorn (Crataegus sinaica Boiss.) grown at Saint Catherin valleys
and mountains in the period from March 2017 to March 2019. The laboratory system of in vitro propagation of
Quince (Cydonia oblonga Mill.) and Hawthorn (Crataegus sinaica Boiss.) was achieved by obtaining the best
sterilization treatment for both plants and achieving a successful establishment by obtaining sterile cultures and
increasing proliferation rate for both plants, in addition to increase multiply shoots in the jars by the best
concentrations of PGRs in the multiplication stage. The rooting and acclimatization stage successfully achieved
in Quince plantlets but did not achieve in Hawthorn plant, so, more studies were recommended in the future to
achieve rooting stage in Hawthorn. And the conservation strategy for both plants by encapsulation/dehydration
technique was done. The genetic characterization between collected individuals of both plants was performed
using ISSR-PCR and the genetic distance between Tynia Valley Quince and Mousa Mountain Quince is shorter
than the Jbaal Valley Quince, while the genetic distance between Jbaal Valley Hawthorn and Tynia Valley
Hawthorn seems not existed and the plants collected from these regions were much similar to each other
according to the genetic characterization but Mousa Mountain Hawthorn was more different from the other
regions. In addition, the evaluation of gene stability was done also by using RAPD-PCR of in vitro propagated
plants produced by tissue culture techniques. The resulted data revealed that there is not any differentiation in the
genetic material of these plants.