TOXICITY AND BIOCHEMICAL EFFICACY OF NOVEL PESTICIDES AGAINST Aphis craccivora Koch (HEMIPTERA: APHIDIDAE) IN RELATION TO ENZYMES ACTIVITY

Measurement of biorational effect of imidacloprid on some aphids spp. as well as on wheat (Triticum aestivum L.) using biochemical parameters and ISSR-PCR

Aphid species are the most common insect pest infesting wheat plants. The LC values of imidacloprid against aphid spp., ISSR-PCR molecular markers and biochemical parameters in wheat plant in the present study were carried out. The LC₅₀ of imidacloprid on Rhopalosiphum maidis, Rhopalosiphum padi, Sitobion avenae, and Schzaphis graminum were 71.626, 85.853, 91.05, and 115.806, respectively. While, the biochemical parameters in treated wheat plants including; total protein, RNA, and DNA contents increased in all experimental groups. Moreover, total carbohydrates and soluble sugar also increased in treated wheat seedlings. Also, the genetic diversity studies revealed that among six ISSR primers produced 36 amplified DNA fragments in a molecular weight range of (480-1545 bp). About 28 fragments were monomorphic, and 8 fragments were polymorphic. It can be concluded that the effectiveness of imidacloprid against sucking insects in treated wheat plants may due to few genetic variations and some metabolic changes in the Triticum. aestivum. PRACTICAL APPLICATIONS: The current study indicated that the potent efficacy of imidacloprid against different aphid spp. which were the most insect pest in wheat plants. As well as the application of imidacloprid as seed dressing insecticide, significantly increase carbohydrate, protein, amino acids, and RNA content in T. aestivum plants. While there was no significant increase in DNA in treated one. The recorded increase in these biochemical parameters may due to the increase in the gene expressions as a result of the application of such pesticides. These results explain the extra mechanism of the effect of imidacloprid against sucking insects. Also, the conducted results explain the effect of imidacloprid as a seed dressing insecticide in wheat crop protection from sucking insects and increasing seed germination, increasing seed wheat and number of seeds/spike.