الفهرس | Only 14 pages are availabe for public view |
Abstract 1. INTRODUCTION Faba bean (Vicia faba L.) ranks first among the food legume crops grown in Egypt for human consumption. It is an important food crop being consumed in both the green succulent state and dry edible seeds.The average cultivated area over last five years (2002-06) was 266,000 feddans. This area is located under three ecological regions North Delta, Middle and Upper Egypt. The average seed yield per unit area was 9.17 ardab/feddan.It is providing between 20-40% protein, B complex vitamins and minerals, so it is considered a good source of protein. Seed yield reduction at North Delta may be mainly attributed to foliar diseases incidence i.e., chocolate spot (Botrytis fabae) and rust (Uromyces fabae) diseases. Chocolate spot disease, caused by Botrytis fabae Sard, is one of the major diseases of faba bean in the Middle East, North Africa, and Europe (Wilson,1937; El–Helaly, 1938; Moore, 1949), severe outbreaks of chocolate spot on faba bean were reported in several countries (Wilson, 1937; Moore, 1949; Grainger, 1950; Williams, 1975; Ibrahim et al, 1979; and Mohamed, 1982) Disease management today is based mainly on expensive fungicides and modified cultural practices, which provide only partial protection, however, development of resistant genotypes is the best practical, most efficient and economical method of fighting a pathogen Since little is known about genetic variability among certain genotypes, type of combining ability, gene expression controlling host reaction in faba bean to chocolate spot or the effect of cytoplasm it was thought desirable to obtain such information formulating an efficient breeding program for developing resistant genotypes. Gene effects are known to be influenced by environmental variation to a large extentKeeping these considerations in mind a diallel mating design with reciprocal crosses in F1, and F2 generations to study nature of gene action for chocolate spot resistance, with regard to seed yield , it component and earliness in flowering Moreover, the breeding potentialities of four faba bean genotypes were evaluated to determine if it is possible to select for chocolate spot resistance and obtaining high seed yield and earliness in flowering. |