Two pot experiments were carried out in the green house of Botany
Department, National Research Centre, Dokki, Giza, Egypt, during two successive
seasons (2000 and 2001). The aim of the present work was to study the effect of foliar
application with benzyladenine, BA (25, 50 and 100 ppm), Pix (25, 50 and 100 ppm)
and the interaction between BA and Pix on morphological and chemical analysis of
soybean shoots (photosynthetic pigments, carbohydrate, protein and endogenous
phytohormones ).
The results revealed that foliar application with BA and/or Pix at all doses
increased significantly the morphological criteria of shoot (Shoot length, stem
diameter, fresh and dry weight, number of branches, number of leaves and leaves
area/plant) and roots parameters (Root length and fresh & dry weights) at vegetative,
flowering and fruiting stages. The most potent effect was observed due to the
interaction treatment than the use of each growth regulator solely. The maximum
promotive effect induced in all morphological growth was detected, in general, at 50
ppm BA + 50 ppm Pix at all stages of plant growth. The data also revealed that the
photosynthetic pigments (chlorophylls and carotenoids) of soybean leaves
significantly increased as affected by BA and/or Pix treatments. The most pronounced
increase in photosynthetic pigments content was accompanied by the increase in total
soluble sugar, polysaccharides and consequently total carbohydrates in soybean
shoots in response to all treatments.
In the mean time, the amino-N, total soluble-N, protein-N and total-N
increased in treated soybean plant's shoots in response to all concentrations of BA
and/or Pix as compared to the untreated plants. The interaction treatments induced
the maxinum values of nitrogenous content as compared with the use of each growth
regulator individually.
8enzyladenine treatments decreased ABA and increased 1M contents, while
a reverse effect was cbserved in response to all Pix concentrations. The endogenous
GAJ and total cytokinins showed marked increases in response to all BA and/or Pix
treatments.