الفهرس 
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Abstract
Two large scale experiments were designed to investigate the possible effects of direct exposure of broad bean seedlings to different light spectra (low visible light, high visible light, UV-A and UV-C, either alone or in combination), as stressful factors on germination and growth and photosynthetic components and the associated effects on primary and secondary metabolites. The purpose of this detailed investigation was to maintain a basis for expected mechanisms involved in this type of stress as well as to check up ways of partial or complete recovery from the induced stress. Exposure of broad bean seedlings to the stressful conditions induced pronounced significant changes in growth parameters, the total amount and in the relative composition of pigment fraction contents. Furthermore, significant variable decreases in PS II activity. Also there are significant variable changes in the total amount and in the relative composition of the carbohydrate pool. On the other hand, significant variable increases in the activities of both invertase and α-amylase. There are significant variable increases in total phenolic compounds as well as in anthocyanin contents, high accumulation of both glycine and proline amino acids. Chenges in protein banding patterns were apparent. There are significant decreases in nucleic acids (RNA and DNA) and significant increases in antioxidant (enzymic and non-enzymic) system.