الفهرس 
Genetic materialOnly 14 pages are availabe for public view
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Abstract
The aim of this investigation was detel-mine the residual heterozygosity in two open-pollinated varieties of Egyptian cotton. One Seed strain of each variety was chosen to standardize the conlparison and these were Giza 77/95 and the other strain was 86/95. In 1997 season 100 plants from each of Giza 77 and Giza 86 varieties were selected at randoin and labeled. The selected plants from each variety were self pollinated to produce S1 families, and at the same time each selected plant was crossed with an inbred line (Giza 77 x Giza 87 and Giza 86 x Giza 75) to produce F1 families on the same plants. Thisteen plants fi-om each variety having enough seeds of both S1 and F1 families were selected to be used in the evaluatioii trial. In 1998 season, two adjacent experiments were conducted separately for the two varieties. Each experiment included the following genetic population; the S1 and F1 seeds fi-om each of the 30 chosen parents, bulked seeds of the open-pollinated parents and self pollinated seed fi-om the inbred line. The measured characters were earliness and growth habit characters as well as ”yield and its components. The hypotl~esis followed in intespreting these data was that if heterozygosity persisted in the open-pollinated populatioiz then the rank of the variances sl~ouldb e a2sl> o2~>1 d 1 . Sumnay of the obtained results are as follows: 1. For earliness and growth habit characters. Variances among S1 progenies were greater than those of Fi crosses for date to first true leaf, date to appearance of first square, date to first flower, date to first opening boll, earliness index and nu~nbero f fixiting brai~chesin Giza 77 variety. While, in Giza 86 variety variances among S1 progenies were higher than those of Fl crosses for date to first true leaf, date to appearance of first square, date to first flower and date to first opening boll.