Effect of Growth Regulators and Modified MS Medium on the Tissue Culture of Cucurbita pepo Plant

Abstract

Callus induction of the plant parts (leaves,stems,cotyledons, hypocotyls) of Cucurbita pepo on the solid medium enriched with different concentrations of auxins such as (2,4-D , IAA,NAA) and cytokinins such as (kin,BA). The medium (MS+1.0mg/L BA+0.5mg/L NAA)has been selected the best medium used to originate callus with an average estimated at 100%in the plant parts namely leaves ,stems and hypocotyls and the cotyledons respectively with an average 83% of callus ,and this was the highest percentage of the fresh weight amounte to 2.0 gm and stems callus at 1.2 gm.The study also succeded in originating callus of immature embryos with high percentage 85% on the medium (MS 0.5mg/L BA+0.1mg/L NAA) after it has been deduced on medium MS supported with 30mg/L 2,4-D for two weeks.Also the medium MS contained 1.5mg/L BA and 0.1mg/L NAA succeded in producing deduction percentage 100% from the cotyledons similary deduction media achieved a percentage ranged between 83-100% of cotyledons with out embryos.The results of altering the components of the selected MS medium (MS+1.0mg/L BA+0.5mg/L NAA)has shown deduction percentage amounted to 100% for the hypocotyls and 85% for the cotyledons when added 7ml/L of NH4NO3 instead of 4ml/L(MSN medium).Once we increased the amount of KNO3 compound up to 14ml/L instead of 8ml/L(MSK medium)on the same concentration of MS medium,the parts of cotyledons achieved the highest percentage of deduction 87%.Finally,the highest fresh weight of hypocotyls callus was noticed in this medium 1.8gm and the highest fresh weight of the cotyledons callus was noticed in MSN medium which was 2.0gm .Key words:Tissue culture,Cucurbita pepo, MS medium,NAA,BA.