تاثير الكلايكول المتعدد الاثيلين (PEG) واشعة كاما في خصائص نمو كالس صنفين من الذرة الصفراء

Abstract

The Present study was conducted at AL- Tuwaitha Experimental Station in fall 2002, using immature embryos at milky stage of Rabee and Al-Masarra maize local varieties (Zea mays L.). Callus was induced on MS medium supplemented with 2,4-D (2,4- dichlorophenoxyacetic acid) for 6 weeks in dark at 26+1 oC. Cultures were transferred to a media containing polyethylene glycol (PEG) at 0, 15, 30 or 45 g/l. Calli were exposed to gamma rays at (0, 3, 6 or 10 Gy) and incubated at the same previous conditions for six weeks. Phenotypic characters concerned with callus growth, callus fresh weight (CFW), and callus growth index were studied. Results revealed the significant effect the PEG on CFW, and exceeding the control treatment, whereas the concentration of 45 g/l PEG gave the least (106.12 mg) and didn’t differ significantly than 30 g/l PEG. AL-Masarra variety exceeded over Rabee variety in CFW. Gamma rays significantly affected CFW. Genotype x PEG x gamma rays interaction showed the significant effect on CFW .Callus growth index for all combinations under investigation showed a wide range (0-3.72) and reflected the exceeding of Al-Masarra variety over Rabee, that may indicate the further response of Al-Masarra variety for selection for drought tolerance.