Isolation of Cell Lines Resistant to Erysiphae cichoracearum by Screening Different Genotypes of Cucumis sativus L.

Leaf derived calli of four genotypes of cucumber susceptible, moderately resistant and resistant plants were screened in vitro for the production of powdery mildew disease (Erysiphae cichoracearum). Three methods were used to get resistance i.e., direct spore suspention, high (30%) and step-wise increase (10%, 20%, 30%) in culture filtrate concentration of Erysiphae cichoracearum. After being exposed to spore suspension, the susceptibility of calli were noticed and arrested the growth of the callus. However, certain parts of the calli were observed that were free from fungal attack and seen proliferating in the toxin containing media. Whereas, the susceptible calli turned brown resulting in death of the calli. Then the resistant cell lines were isolated and sub cultured for the three passages of two weeks. The percentage of these resistant cell lines varied among the four genotypes.