The present study was carried out to study the karyotype characterization of berseem Serw 1 cultivar as male parent and Gemmiza 1 cultivar as female parent, using the satellite chromosomes in Serw 1 as a marker to find out the accurate isolation distances in Gemmiza 1 as female parent, and their first generations polycrosses along 50,100,150 and 200 meter distances from the male parent cultivars (Serw1). The satellites chromsoms were previously found in Serw 1, where Gemmizal has not satellite chromosoms. Satellite chromosoms were not found in the first generations of (Gemmiza 1 x Serw 1) which planted in 100,150,200 m away from the male parent Serw 1, but the satellite chromosomes were found as a markers in the segregated generations of the polycrossed via 50 meter distance (Chromosome number 4 SAT). Also, C – banding technique was used to indentify the parental chromosomes of Serw 1 , Gemmizal and the resulted generations to confirm for how long the pollen grains of Serw 1 could be transfered under the open pollinated conditions for first generation polycrosses along 50,100, 150 and 200 meter distances. In the present study, changes in the chromosomal characterization were detected that indicating pollen grains were transferred from the male parent plants (Serw 1) to the female parent plants, Gemmiza 1 (50 meter distance, at 50 meter distance were recorded the highest percentage of cells containing chromosomal aberrations 24%), significant difference was found in chromosome area. Chromosome length and mitotic index between the isolation distances in all cases, data indicated that differences ranged from the highest score of chromosome area in the variety Serw 1 (male parent plants) to the lowest estimate in the 200 meter, studied isolation distances exhibited variations ranged from the highest score of chromosome length in Serw 1 (male parent plants) to the lowest estimate in the 200 meter distance. The present isolation distance of 50 meter identification of each of the eight pairs of chromosomes of a idiogram. All chromosomes had centromeric bands and a terminal band in the short arm except the satellite chromosome (chromosome Number 4). Interstitial bands were observed in the short arms. Chromosomes 1, 2, 3 and 4 each had one prominent interstitial band in their long arm. The satellite chromosome is easy to identify because of the presence of the secondary constriction.
A minstrel degree of minimum recommended isolation distances for Egyptian clover, it includes three minimum distance recommendations : Isolation distance of 200m for foundation seed. Isolation distance of 150m for registered seed. Isolation distance of 100m for certified seed.