The formation of cucumber resistant plants Cucunzis sativus of Rhizoctonia solani calves and stems

Abstract

In this study callus stimulated from cotyledons and stem explants of cucumber seedlings on MS media supplemented with 2.0 mg/L of BA and 1.0 mg/ L of NAA for cotyledons , while in stem MS media containing 1.0 mg/L from BA and NAA were used . Selection of resistant callus to the virulent strains of Rhizoctonia so/ani was examined from culture of cotyledons and stem medium contained the concentrations 1.0, 5.0, 10.0, 15.0, 20 and 25% of fungal filtrates. The best concentrations which allowed selection after three cycles ( 20 days I cycle) of selections were 10 and 15% . The resistant callus showed a high level of peroxidases enzymes activity . Resistance callus of cotyledons and stems were regenerated on MS medium containing 4.0 mg/L of BA and 0.1 mg/L NAA in spite of reduction of the regeneration ability of the resistant callus up to half in cotyledons and stems compat~d-with the control plants. Regenerated stems formed roots on MS medium without grouth regulators . Cucumber plants regenerated from callus tolerating toxic filtrates exhibited resistance when infected with pathogenic fungi .

Keywords

• cucumber
• calves
• stems