Efficiency of Selection for Seed Cotton Yield under Newly Reclaimed Lands Conditions

Selection for seed cotton yield plant -1 was applied in F 2 , F 3 and F 4 -generations of a population of cross Giza 80 X Giza 90 cotton. The experiment was carried out during three successive summer seasons; 2019, 2020 and 2021 at farm west of Minia, El Minia under new reclaimed lands conditions. Entries mean squares of the selection criterion; seed cotton yield were significant or highly significant in F 3 and F 4 -generations. Reduction was observed in the phenotypic and genotypic coefficients of variability from F 3 to F 4 compared to the phenotypic variation in F 2 for the most studied traits as a result the selection for seed cotton yield/plant and reduction the genetic variation. Moreover, increasing the homozygosity. The four selected families of no. 13, 17, 18 and 26 were showed highly significant increase compared to both bulk and better parent for the two traits seed cotton yield and lint yield plant -1 . Seed cotton yield /plant was showed positive genotypic and phenotypic correlation coefficients with bolls weight, lint yield /plant -1 and number of bolls plant -1 . While, negative correlations were observed for Seed cotton yield / plant with each of lint percentage and lint index on genotypic and phenotypic levels.