الفهرس 
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Abstract
Maize genotype specificity has been one of the constraints limiting the transformation of many tropical and subtropical maize lines with desirable genes. In the present study callus induction and regeneration ability from immature embryos of four elite Egyptian maize lines were examined. Two media were assayed to investigate the effect of 2,4-D and dicamba on type II callus production and regeneration. Dicamba promoted fast differentiation in all inbred lines that led to increasing the number of shoots in comparison to 2,4-D.Inbreds Gz 650 and Sd 34 gave significantly high regeneration frequencies when maintained on callus induction medium containing dicamba. The late embryogenesis abundant (LEA) protein coding gene, HVA1, from barley (Hordeum vulgare L.) for abiotic stress tolerance along with the bar gene for herbicide resistance were introduced in three of these inbred lines using the biolistic mediated transformation method and independent transgenic events were obtained. Putative transgenic events have been tested by herbicide application. Moreover, molecular analysis using PCR and Southern blot hybridization proved the presence and integration of the transgenes in the genome of the putatively transgenic plants. The copy number of the transgenes ranged between 10 and 15 copies in individual events. This study suggests that LEA genes could hold considerable potential for use as molecular tools for genetic crop improvement toward stress tolerance.