Potential of molecular marker techniques to identify the susceptibility of some Egyptian cotton varieties to bollworms and whitefly infestation

The current investigation was conducted to study the response of six cotton varieties Giza 45, Giza 87, Giza 92, Giza 94, Giza 96 and Giza 97 to infestation of the Pectinophora gossypiella (Saunders), Earias insulana and Bemisia tabaci, the genomic DNA extraction and purification were studied under field conditions at the experimental farm of Sakha Agricultural Research Station, Kafr El-Sheikh Governorate, through 2024 and 2025. Therefore, results showed that, Giza 94 variety was the most susceptibility to infested by P. gossypiella, E. insulana and B. tabaci, while Giza 97 variety was the opposite any the most resistant for the same pests and recorded the number during the two seasons. While, the other varieties of infections are mean. Results showed that the significant differences between Giza 94 and each of the other cotton varieties. Present study can be helpful in selecting resistant varieties in the development of IPM strategies against bollworms and whitefly for good quality production of cotton. Also, this study used ten SCoT primers to generate 130 DNA bands, averaging 13 per primer, with 37 polymorphic bands (41.16% polymorphism). Primers SCoT-1 and SCoT-9 produced the most bands, while SCoT-4 showed the lowest polymorphism, highlighting useful variations for cotton DNA identification.