الفهرس 
HeterosisOnly 14 pages are availabe for public view
 |  | from | 129 |  |  |
| | | from | 129 | | |
Abstract
The purpose of this study was to determine the results of crossing some European and Egyptian faba beans. A mating design was chosen to determine the relative magnitudes of the different genetic parameters. For that purpose, the genetic materials in the present investigation included five European and five Egyptian varieties and a total of 50 F1 hybrids which resulted from a factorial mating design between the two groups including reciprocals. The parental varieties were : 1. European varieties included : Webo, Kristall, NS-74, TP 3930/80 and Wierboon. 2. Egyptian varieties included : Giza 1, Giza 2, Giza 3, Giza 402 and Rebaya 40. In 1983 season, all possible combination crosses between the two groups of parents were conducted in the nursery of the Plant Breeding Institute, University of GGttingen, F. Rep. Germany under the supervision of Prof. Dr. Dr. h.c. Gerhard R8bbelen. In 1983/1984 season, the F1 hybrids and their parents were sown in screen cages of the Faculty of Agriculture, Kafr El-Sheikh, Egypt. In 1984 season, the parental materials were reduced to three parents from each group according to the flowering characteristics of the F1. The 18 F2 combinations and their 6 parents were sown at Reinshof breeding nursery at Gottingen. ,-. The experimental design used was a randomized complete block design with three replications. Data were recorded on individual plant basis. In each plot 10 plants were selected at random to evaluate the F1 generation, while the whole population (50 plants/plot) were used to evaluate the F2. The obtained results can be surnmerized as follows : 1. There is no maternal effect in the present materials in both generations indicating that the studied characters are affected by chromosomally inherited factors. 2. The results of the analysis of variance indicated the presence of significant differences between genotypes (crosses and their respective parents) for all traits studied except the efficiency in seed yield production per day, in the F2 generation. 3. The means of crosses showed that the combinations between the latest as well as the earliest varieties from each parental group produced the latest and the earliest crosses, respectively. However, this kind of relationships did not usually hold with respect to yield and its components. 4. The results of F1-generation showed that the varieties Wierboon, Kristall from the European group and Rebaya 40 from the Egyptian ones were the most favourable varieties to produce a most favourable hybrids for earlier ripening without sacrificing seed yield. 5. The varieties Wierboon from the European group and Giza 3 from the Egyptian one had the important components for high seed yield. Moreover, the hybrid between the two parents outyfelded all other parents and hyrbids. 6. Among the 25 F1 hybrids, there were only 10 lower yielding hybrids than the highest yielding parents, indicating the impartan~e af hybridization between the two parental groups. 7. The behaviour of the F2 plants showed an array of intermediates between parental characteristics for most sf the traits studied. 8. Appreciable heterosis over mid-parent was obtained for pre -anthesis growth phase, number of pods and seeds per plant, 100 seed weight and seed yield per plant. 9. Mean heterotic values over all hybrids were found to surpass the best performing parents for seed yield and the two main yield components; number of pods and seeds per plant. 10. The magnitude of heterotic values over better parent found in F1 materials were expected, because the parental varieties from each group are not related, and each of them is derived from a different germplasm, therefore, the expected selection programs in these materials in the segregating generation would not be .limited to the superior specific hybrids, and the expected improvement would be fruitful. 11. The heterotic effects were due to over-dominance for all cases except for pre-anthesis growth phase over mid-parent where it was a result of partial dominance.