A CONSEQUENT STUDY TO DIMINISH ANTI·NUTRITIONAL FACTORS (VICINE AND CONVICINE) CONTENT AND PHYSIOLOGICAL RESPONSE OF SOME EGYPTIAN FABA BEAN CULTIVARS TREATED WITH GA3

Two pot experiments were carried out during winter seasons 2002 and 2003
at the green house of the experimental station of Botany department, National
Research Center, Dokki, Giza, Egypt. The experiments aimed to study the effect of
foliar spraying 100 ppm GA3 on 5 varieties of Vicia faba plants (Giza 40, 429, 461,
643 and 674) on growth, photosynthetic pigments, yield, yield components, the
contents of toxic constituents (vicine and convicine) in green pods and dry seeds
(yielded seeds) at harvest. The contents of protein and amino acids composition of
two varieties (Giza 429 and Giza 674) were focused.
The results revealed that foliar spraying of 100 ppm GA3 enhanced all the
morphological criteria (number of leaflets, number of leaves, number of flowers, leaf
area per plant, fresh and dry weight of shoots as well as the yield and its components
(plant height, plant weight, number of branches, number of pods, number of seeds
and 1 OO-seeds weight in all varieties of Vicia tebe plant.
The different varieties of Vicia tebe treated plants showed an increase in
chlorophyll a, chlorophyll b, carotenoides and consequently total pigments compared
with untreated plants.
Marked reductions were observed regarding the toxic glucosides (vicine and
convicine) which are the main purpose of the presented work, in response to 100 ppm
GA3 of all varieties especially Giza 429 and Giza 674 which showed a marked
reduction in green pods and dry seeds. This reduction was increased when the
yielded seeds of all varieties re-treated by soaking in 100 ppm GA3 solution. This
reduction reached nearly to 53 and 58% in Giza 674 and Giza 429, respectively.
Moreover, the amino acids composition of these two varieties increased markedly,
except for th ~ sulphur amino acids (cystin and methionine) of Giza 674 in response to
GA3 treatment which improved the quality of seeds. Also, the protein content in Vicia
teb» seeds of the two markedly responded varieties recorded the highest values
under the effect of GA3 foliar spraying.