Comparative Study on some Pure Successive Maintained Nuclei (Foundation Seed) of Giza 95 Cotton Cultivar and its Corresponding Handled one’s in General Cultivation.

Four successive pure maintained nuclei (N) and four handled farmer's seeds (F) of Giza 95 Egyptian cotton cultivar were used to evaluate the changements that might occur in earliness, yield ,fiber quality and genetic constitution of the cultivar after handling the seeds by the farmers. Two field experiments were carried out at Sids Agric. Res. Station, throughout growing seasons 2017 and 2018. Genotypes mean squares were significant and/or highly significant for seed cotton yield, lint yield, earliness index and yarn strength in both seasons and combined analysis. The greatest amount of differences among the studied  strains were mainly due to the variances among the farmer's seeds and the interaction (N vs F), for these characters indicating farmer seeds might get genetic imperfection due to mechanical mixture or out-crossing by off-type plants. The interactions of genotypes by environments (G x E) were insignificant for all studied characters except boll weight and fiber fineness. Regarding mean performances, the results indicated that the pure nuclei strains surpassed the farmer's ones for most studied traits. The older farmer's strains (G.95/2014) exhibited lower mean performance estimates for most studied yield traits over the two environments and it’s combined data. Also, nuclei seeds gave the best performances for most fiber properties compared with the farmer's ones. Seed cotton yield in both nuclei and farmer's strains was positively and significantly related with earliness index and fiber fineness suggested that any changes when appear in these characters may be correlate with decrease of seed cotton yield or any deterioration appeared.