Enzymatic activity as biochemical markers for detecting cucumber and squash tolerance to nematode infection [electronic resource].

Includes references.

Classical host suitability designations of three cucumber and three squash cultrivars were used for the plant-parasitic nematode Meloidogyne javanica infection. Enzyme assays were implemented concerning three systems of enzymes peroxidase, esterase and acid phosphatase in M. javanica-infected and non-infected plant roots in order to contrast such designations with a novel approach of using enzymatic activity as biochemical markers for their rating. Under uninfected conditions, the cucumber cultivar Royal Sluis revealed peroxidase activity higher than the two other cultivars. After nematode infection, however, such an activity reached as high as 103.8% at Alzaeem cultivar which might confirm the classical rating of its tolerance to nematode infection. The enzyme activity increased after infection but to a less degree in the other two susceptible cultivars ofcucumber as compared to the uninfected plants. On the other hand, tlte uninfected squash cultivar Arlika, rated as nematode tolerant because there was no significant difference between growth parameters of uninfected and infected plants which had high nematode reproduction capability, manifested the highest peroxidase activity. Yet, the enzyme activity generally decreased in the three squash cultivars after infection as compared to the untreated controls except esterase enzyme in Arlika cultivar where a 75.7% increase in its activity occurred after nematode infection.

Summary in Arabic.

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