Experiments carried out through 2016 revealed that a proper protocol for the in vitro propagation of Koronaki and Coratina olive cvs. as follows : Sterilization of stem node explants was carried out successfuly with copper sulphate at 50mg/l for Koronaki cv. And Ampicillin at 150mg/l for Coratina cv. both cultured on Olive medium.Multiplication on MS medium enriched with BAP at 1.5mg/l for both cvs.  Rooting of Koronaki on half sterngth OM medium enriched with IBA at 0.5mg/l and Coratina on half sterngth MS medium enriched with NAA at 0.1mg/l.  Acclimization of Koronaki plantlets derived from half strength OM rooting medium and acclimatized on peat : sand  (1:1) and Coratina plantlets derived from MS rooting medium and acclimatized on peat :sand : vermiculite (1:1:1).

Olive tree (Olea europaea L.) is one of the most important fruit trees, there is a lot of varieties with the possibility of mislabeling, homogenouses and synonyms, which makes major troubles when having plant material for propagation and breeding programs. In this search, 12 olive varieties (Mawi Istanbuli, Khilkhali Khishen, Dan, Mniekri, Adkam, Doaibli, Jlot, Khilkhali Saghir, Karamani Modabal,       Mawi abo Shokeh, Sourani, and Abo Shokeh),  cultivated in ACSAD Gene bank in Gellin, were characterized by ISSR molecular markers to determine the relationship between these varieties. Depending on quantitive traits the results indicated that these varieties are so close to each other's, ranged from 60% and 85%. It was noticed that Mneikri was apart from the other varieties in its traits, (polymorphic rate was 92.94%).

Several nurseries of olives in Fayoum and Giza were surveyed for root rot incidence during early summer of 2003. In Fayoum, root rot incidence reached 53% while in Giza, disease incidence was 44%. Disease symptoms consist of partial wilting, leaves browning and twig dieback, which was associated with severe root rot and basal stem cankers and followed, in most cases, by plant decline and death. The most frequently isolated fungi from rotted roots were Fusarium oxysporum, F. solani, F. moniliforme, Rhizoctonia solani, Sclerotium rolfsii, Cylindrocarpon sp.  and Alternaria alternata. Isolation frequency of different fungi varied among olive cultivars. Generally, Fusarium spp. were the most frequently isolated  pathogens and Fusarium oxysporum was the most frequent (35.5%) on all cultivars followed by F. solani (19.3%) R. solani (16.1%). Meanwhile, S. rolfsii, F. moniliforme, Cylindrocarpon sp. and A. alternata occurred at lowfrequencies. Pathogenicity tests showed that all tested isolates caused varied degrees of root rot symptoms on olive transplants, cvs. Manzanillo and Picual. Fusarium oxysporum, F. solani and R. solani caused the highest root rot incidence and severity on both cultivars. There was a positive correlation between disease severity on roots and severity of foliar symptoms. All evaluated olive cultivars were susceptible or extremely susceptible to fungal pathogens. All cultivars showed high disease severity with root rots, especially in response to infection by F. solani, F. oxysporum and S.  rolfsii. However, the least foliar symptoms were recorded on cultivar Coratina. Application of two commercial biological control products (Rhizo-Plus and Trichoderma 2000) to soil, 24h before planting olive cuttings in the nursery, significantly reduced incidence of root rot on transplants of cultivars Manzanillo and Picual, up to 28 weeks after planting

Four olive cultivars namely Manzanello, Picual, Coratina and Arbicon grown at Wadi El-Natroon area, Egypt under drip irrigation system in sandy soil were compared for optimizing their own yield as well as fruit quality parameters during 2001 (off-year) and 2002 (on-year), by application of an integrated and balanced fertigaion program including macro and micro-nutrients. Results showed that remarkable and significant differences in leaf mineral contents, yield and yield quality parameters were detected by using well distributed fertilizer program during the growing season of olive trees. The treated four cultivars attained higher yield in the “on” and “off” year than the control. The most outstanding olive cultivars having greater yield were Picual, Manzanello, Coratina and Arbicon in a descending order. Oil percentage was maximized with Picual olive while, Arbicon olive had the lowest value. Free fatty acids (%), Iodine number as well as Acidity (%) were minimized in Coratina olive and the lowest peroxide number as was in Picual olive. It is apparent that for planting Picual olive variety proved to be the promising one due to its greatest yield and best fruit quality specially when the actual requirements of macro and micro nutrients were used through the drip irrigation system.

The present work aimed to establish a protocol to minimize the potential effect of in-vitro preservation for 8 months of the two olive cultivars i.e Koronaiki and Kalamata. Three culture conditions (treatments) were chosen to investigate the most suitable one for minimizing somaclonal variations after the process of in vitro preservation. The conditions include MS medium plus mannitol, MS medium plus low temperature and MS medium plus naphthaline acetic acid. RAPD-based finger-printing was employed to determine the effects of the different chemical constituents and other culture conditions on the extent of somaclonal variations after 8 months of in vitro preservation at the DNA level. Four arbitrary primers (OPA-04, -07, -14 and -16) were successfully utilized to achieve such goal. The obtained results showed that Mannitol has more pronounced effect than the other investigated preservation culture and conditions for decreasing DNA alterations.