Chemical evaluation of strawberry plants and fruits produced by tissue culturing of gamma irradiated seedlings [electronic resource].

Includes reference.

Studies were conducted to evaluate the influence of gamma irradiation preceding tissue culturing of strawberry seedlings (c.v. Rosa linda). The strawberry seedlings were irradiated using 8 doses of gamma rays i.e. 50, 75, 100, 125, 150,250,350 and 500 Gray. Tissue culture technique was applied on irradiated and un-irradiated (control) strawberry seedlings. Chemical characteristics of strawberry plant and fruit were studied as well as the early, total and exportable fruit yields. Data indicated that the radiation doses over than 250 Gray are lethal since the relatively high radiation doses i.e. 350 and 500 Gray affected markedly the strawberry seedlings and did not show any growth parameters. Carbohydrate fractions, total nitrogen, amino acids and protein contents showed remarkable increases in strawberry plant by the application oflow doses (50, 75 and100 Gray) while they showed gradual decrease by increasing the radiation doses, whereas phenolic compounds content increased gradually by increasing radiation doses. Concerning strawberry fruits, the data revealed that the higher carbohydrate fractions content were obtained by the application of low doses (50, 75 and 100 Gray) and then the higher the radiation doses the lower the carbohydrate fractions content were obtained. On the other hand, amino acids, phenolic compounds and anthocyanin in fruits increased gradually by increasing the radiation doses. The fruit yields recorded remarkable increase. About 46% increase in the early yield was obtained after exposure to 50 Gray, while 51.9% increase in the total yield was obtained by the same dose. In addition, 56.4% increase in the total fruit yield was achieved after exposure to 75 Gray. Moreover, exposure to 50 Gray produced 27.7% increase in exportable fresh fruit yield at the end of the season. It could be conclude that the exposure to low and safely doses of gamma radiation (50.75 and 100 Gray) is recommended before tissue culturing of strawberry seedlings in order to achieve higher yield and high quality strawberry fruits either for local and/or foreign markets. Key words: Gamma irradiation, tissue culture, strawberry, plantlets, exportable fruit yield.

Summary in Arabic.

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