Papers by Mabrouk Elgabry
Five commercial tomato (Solanum lycopersicum L.) cultivars and their ten F 1 hybrids were used in... more Five commercial tomato (Solanum lycopersicum L.) cultivars and their ten F 1 hybrids were used in order to detect the general performances and estimation the heterosis percentages, potence ratios, and phenotypic correlation coefficients among all possible pairs of some important tomato's characters. The obtained results reflected a range of significant variability for most of the traits studied. The general performances of the F 1 hybrids reflected the presence of various degrees of dominance effects; i.e., partial-to overdominance for the characters of plant height, number of primary branches per plant, pericarp thickness, fruit firmness, total soluble solids, ascorbic acid content, number of flowers per cluster, number of fruits per plant and total fruits yield per plant. Whereas, some others studied characters; i.e., fruit shape index, locules number per fruit and fruit weight, illustrated the presence of partial-to under-recessiveness; but, with different degrees. All 10 F 1 hybrids had significantly higher number of fruits per plant and total fruits yield per plant than their respective mid-parental values, meanwhile for the other traits, hybrids exhibited average heterosis in both directions. The mid-parent heterosis varied from −16.04 to 29.75% for plant height, −5.74 to 20.95 for number of primary branches per plant, −34.72 to 15.18% for fruit shape index, −35.72 to 49.02% for number of locules per fruit, −9.22 to 25.88% for pericarp thickness, −5.02 to 15.21% for fruit firmness, −11.46 to 25.50 for total soluble solids, −1.26 to 15.66% for ascorbic acid content, −9.39 to 22.48% for number of flowers per cluster, 4.37 to 104.69% for number of fruits per plant, −32.78 to 11.29% for average fruit weight, 22.29 to 64.33% for total fruits yield per plant. Significant positive correlation between total fruits yield per plant and each of the number of flowers per cluster, number of fruits per plant and average fruit weight was detected. On the other side, significant negative correlation was observed between number of fruits per plant and fruit weight.
General and specific combining ability (GCA and SCA) were estimated using five tomato cultivars a... more General and specific combining ability (GCA and SCA) were estimated using five tomato cultivars and their F 1 hybrids, using diallel cross system without reciprocals. Heritability percentages in narrow sense were, also, calculated for the different studied characters of tomato. The obtained results indicated, generally, that a particular cultivar or hybrid cannot be used to evaluate all studied characters with equal efficiency. However, the best general combiner parent which appeared to have the significant highest positive values of GCA was found to be the cultivar Super Marmand for the characters; plant height, number of flowers per clusters, ascorbic acid content and total soluble solids; the cultivar Edkawy for number of primary branches, number of locules per fruit and fruit weight; the parental cultivar Peto-86 for number of fruits per plants, fruit shape index and pericarp thickness; and Super Strain-B for fruit firmness and total fruits yield per plant. The obtained results illustrated, also, that the best hybrid combinations that reflected the highest positive values of SCA; which means that the parents of this particular cross can combine well to produce a hybrid with high general performances were found to be those of the F 1 hybrids Peto-86 × Edkawy for plant height and total soluble solids; CastelRock × Peto-86 for fruit shape index, fruit weight and total fruits yield per plant; Super Marmand × CastelRock for number of flowers per cluster and number of fruits per plant; Super Strain-B × Super Marmand for ascorbic acid and T.S.S.%; and Super Strain-B × Peto-86 for fruit firmness. Narrow sense heritability estimates were found to be in the range from −37.33% (not different from zero) for the number of flowers per cluster up to 86.69% for fruit firmness characters.
Uploads
Papers by Mabrouk Elgabry