الفهرس 
REVIEW OF LITERATUREOnly 14 pages are availabe for public view
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Abstract
• Tests of significance for mean squares revealed that all genotypes were highly significant for all studied traits with respect to the data from each season and the combined analysis over the two seasons. This finding indicated that these genotypes are differed in their performance and further partition of this genetic variance to its components and the determination of heterosis estimates for these traits are valid. In addition, the result revealed that the mean squares of season by genotypes were highly significant for number of primary branches per plant, leaf area, days to first flowering, number of fruits per plot for the first three pickings, weight of fruits per plot for the first three pickings, total number of fruits per plot, total weight of fruits per plot, pericarp thickness, shape index, carotene concentration and ascorbic acid content. This finding indicated that these genotypes differed in their performance from one season to another with respect to the studied traits.The mean performance of parental varieties showed that no specific parent was superior for all studied traits. However, it appeared that Cherry was the best for plant height, number of fruits per plot for the first three pickings, total number of fruits per plot, Chlorophyll concentration, total soluble solids and ascorbic acid content, while Fatma variety was the best for leaf area, days to first flowering, number of nodes carrying first flowering branch and shape index. Therefore, Edkawey exhibited highest mean for weight of fruits per plot for the first three pickings, total weight of fruits per plot, pericarp thickness, fruit firmness, fruit length, fruit diameter carotene concentration and lycopene content. Castle Rock variety was the best for number of primary branches per plant and number of locules per fruit.The results of the estimated amounts of heterosis over mid- parents (M.P) was insignificant for some traits and highly significant for the other traits. The amount of heterosis ranged from – 5.59% to 648.67% for DFF to TNF, respectively. Also, the estimated amounts of heterosis over better parent (B.P) were insignificant for some traits and highly significant for the other traits. It ranged from -2.34% to 637.77% for DFF to TNF, respectively. Also, it could be showed that some hybrids exhibited positive or negative significant heterosis values over mid parents in some studied traits but their reciprocal did not. Also, some other reciprocals exhibited positive or negative significance heterosis values over mid parents in some studied traits but their hybrids did not. This indicated the role of maternal effect in the inheritance of these studied traits.The results indicated that the mean squares of G.C.A., S.C.A. and reciprocal effects were highly significant for the most traits. Also, the results indicated that the mean squares of (G.C.A.) were higher than those of the mean squares of (S.C.A.) for PH, N.P.B, D.F.F, N.N.F.F.B, NF3P, WF3P, TNF, TWF, F.F, P.T, F.L, F.D, CLt, Carotene and Lycopene concentration. This finding revealed the importance of additive genetic variances in the inheritance of these traits. But the mean squares of S.C.A. were higher than those of the mean squares of (G.C.A.) for N.L.F, T.S.S and Ascorbic acid content, respectively which indicate the importance of non-additive genetic variances in the inheritance of these traits.The variety Advantage 2 was the best general combiner for PH, N.P.B, F.F, CLt and Carotene concentration. While variety Fattma the best general combiner for L.A, D.F.F, N.L.F, P.T, S.I and Lycopene concentration. Thus, these varieties could be involved in the breeding program for improving these traits.In conclusion, the results of this investigation presented evidence about the presence of heterosis in tomato. Additive and non-additive genetic variance in addition to cytoplasmic genetic factors contributed in the inheritance of the studied traits. Although, the predominant of dominance genetic variance in the inheritance of most studied traits, additive genetic variance predominated in the inheritance of plant height and yield traits. Therefore, the plant breeder would design programs, which make use of these advantages to select superior lines from these advantages to select superior genotypes from the advanced segregating generations of the high yielding hybrids. Therefore, these results recommended the recurrent selection program to use both additive and non-additive gene action in the improvement of these traits.