MAINTENANCE AND PRODUCING OF THE NUCLEOLUS (BREEDER’S SEED) OF GIZA 92 EGYPTIAN COTTON CULTIVAR (GOSSYPIUM BARBADENSE L)

The breeding program of the cultivar Giza 92 was conducted at Sakha Agricultural Research Station, Kafr El-Sheikh district during 2013 -2016 growing seasons to initiate a nucleolus. In 2013 season thirty one type plants
were selected from the breeding field of Giza 92 cultivar and provided thirty one progenies (increase A) in 2014. From increase A, seventeen families were selected to establish increase B in 2015. According to the statistical
analysis of yield trial which included the seventeen families and comparisons of the latest three lines in cultivation of Giza 92, Seven elite families were selected and the seeds were carefully massed together to form the nucleolus
(breeder's seed) in 2016 season. The results obtained indicated that, the pure line method in the sense of pedigree selection for renewing annually Giza 92 breeder's seed could produce high genetically pure seeds and meantime,
prevent genetic deterioration. Meanwhile, the selection technique for producing breeder's seed of the variety was valid and proved to be effective in holding this variety according to the standard type of Giza 92.