Chemical and Genetic Evaluation of Somaclonal Variants of Egyptian Garlic (Allium sativum L.)

Abstract

Garlic (Allium sativum L.) is used in the household and as an ingredient in many pharmaceutical products. Tissue culture technique provides an excellent source for induction of both chemical and genetic variation in garlic. A callus was induced on root meristem cultured on Murashige and Skoog (MS) medium in the presence of kinetin, indole acetic acid, and 2,4-dichlorophenoxyacetic acid. Shoots with a small bulb were produced on medium containing MS salts, B vitamins, and naphthalene acetic acid. Regenerated plants were transplanted into soil, and a nondivided bulb was formed in the first somaclonal generation (SCI). Plants were normal in their phenotypes in SC2. After four cycles of field cultivation, the selected somaclones (variants) in the fourth generation showed significant differences in bulb character compared with the original plants. Mitotic division and chromosomal abnormalities were investigated in meristimic root tip cells of regenerated plants for the first and fourth regeneration and for control plants. Somaclonal variant metaphase cells had the same chromosome number (2n = 16) as those of the controls. Allicin was measured quantitatively in the regenerated clones by high-performance liquid chromatography. The results showed that some clones contained as much as 14.50 mg/g allicin, compared with 3.80 mg/g in the control plant. This finding suggests that this technique may be useful to improve the allicin content of Egyptian garlic, which could be utilized as a good source for garlic-containing pharmaceutical preparations.