الفهرس 
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Abstract
This investigation aimed to study the inheritance of some quantitative traits in faba bean genotypes as well as, to identify some biochemical markers which may play a role in the resistance mechanism to Orobanche crenata by investigating different parameters, isozyme polymorphism and electrophoretic protein profiles. Eleven faba bean cultivars and their 28 F1 hybrids which produced according to 4x7 factorial mating design were evaluated under natural infested soil with Orobanche crenata seeds. The results revealed that mean squares of genotypes were significant for all studied traits, indicated the existence of genetic variability among studied genotypes particularly for reaction to Orobanche. The mean performances of the studied parental cultivars could be arranged into three groups, the first group included resistant genotypes, second group, includes the partial tolerant to Orobanche and the third group includes susceptible parents. In addition, the best heterosis value for earliness was detected in the crosses; Misr 1 x Sakha 1 and Misr 1 x Sakha 2 are having significant negative heterotic values over their mid-parents. The resistant genotypes Misr 1, C.1657 and Misr 2 and also the earliness genotypes Sakha 1, T.W and C. 1543 have greater combining ability effects for seed yield/plant than the other genotypes. Furthermore, the best combination for reaction to Orobanche was C.1657 x C.1543. The estimation of dominance degree ratio for studied traits was confirmed that the importance of additive genetic variance for plant height and number of seeds/plant. Heritability in the broad sense estimates were larger than the corresponding values of narrow sense heritability for studied traits, indicating that a major part of the total genotypic variance is additive. The results of biochemical analysis revealed that most of resistant parents were found to lack esterase transcription; therefore, esterase could be used as a marker for the Orobanche resistance. The peroxidase activity was found to be increased considerably during the course of the defense reaction against invading parasites. The analysis of seed proteins by SDS-PAGE revealed that the heterotic effect in the F1 protein banding pattern in the two crosses; Misr 1 x Misr 2 and Misr 1 x Sakha 2 exhibited a unique sharp band (no. 1 and 3, respectively). These two unique bands could he used as markers for Orobanche tolerance because the resistant parent Misr 1 contributed to the two crosses. Transverse sections in the lateral roots revealed that there were no differences between the genotypes with respect to the main structure of the root. All roots were in the secondary state of growth, but the susceptible genotypes (BPL 710) exhibited more amount of secondary vascular tissues, in comparison with the resistant genotypes. Furthermore, another anatomical difference recorded between the susceptible variety BPL 710 and the two resistant ones, Misr 1 and Misr 2, with respect to diameter of root, thickness of cortex tissue, diameter of vascular cylinder and diameter of xylem vessels.In conclusion, due to all previous results, it could be suggested that the selection program is the best way for prediction a new resistance Vicia faba types using a biochemical and anatomical markers