Field experiment was conducted with 16 treatment combinations consisting of four levels of irrigation (0.4, 0.6, 0.8 and 1.0 IW/CPE ratio) at 60 mm depth and four levels of N (0, 50, 100 and 150 kg N/ha/yr). It was conducted in split plot design with four

Blackberry (Rubus fruticosus L.) is a shrub with great importance because of its fruits and /or aerial parts have a wide use in pharmaceutal, medicinal and industrial healthcare purposes, in-addition to their nutritional value. In the present study, inter simple sequence repeats (ISSR) and sequence-related amplified polymorphism(SRAP) analyses were used to evaluate genetic stability of Rubus fruticosus L.̔̔ Triple Crown̕ micropropagated plantlets and compare or detect possibly existing genetic variation between them and their donor mother plant. Introduced shoot tips of Rubus fruticosus L.̔̔ Triple Crown̕ were micropropagated in North Sinai Research Station, Desert Research Center. Sterilized excised shoot tips of them were cultured on MS basal salt medium supplemented with benzyl adenine 0.5 mg/L. Then developed shoots successfully transferred to multiplication media for several subcultures and subsequently to rooting medium. Genomic DNA of five micropropagated plantlets (samples) that were phenotypically normalregenerates and essentially identical with their mother plant, in-addition to their donor (mother plant) was extracted using modified CTAB method. Ten ISSR primers and twenty three different SRAP primer combinations were used for this study. Comparisons of each ISSRand SRAPbanding patters average ofmean percentage of similarity which calculated by Nei & Li similarity coefficient and dendrogams constructed based on the UPGMA clustering method showed that the micropropagated plantlets (samples) exhibited somaclonal variation and not true-to-type. Also, polymorphic information content and marker index values for the two markers indicated the presence of polymorphism between the studied samples and their mother plant. In-addition, the discriminating capacity and efficiency of ISSR and SRAP markers for genetic analyses were high, but SRAP markers had better capacity for comparative study and quantifying genetic diversity between Rubus fruticosus L. ̔Triple Crown̕ micropropagated plantlets (samples) and their mother plant.