Quantitative Study of Cry1Ac Protein and Bioassay for Helicoverpa armigera at Different Development Stages of Upland Cotton (Gossypium hirsutum L.)

Abstract

Eight transgenic (Cry1Ac -endotoxin) genotypes and one non-GMO cotton (Gossypium hirsutum L.) variety were used in the investigation. Cry1Ac protein was expressed at various extents in several strains. In a greenhouse environment, sixty days after planting, the cry 1Ac gene's expression peaked. At 60 DAP, the variety Bt.CIM-598 (1.871 g/g) expressed the most toxin of any genotype. Throughout the cropping season, larvae of the Helicoverpa armigera were gathered from every section of the nation that produces cotton. H. armigera larvae that were captured in the field were raised on artificial feeds. There was a negative relationship between the DAP and the amount of Cry1Ac protein (-0.332). The greatest amount of death was seen when first-instar larvae consumed the leaves of 60 DAP plants. It was found that transgenic variants had a considerable effect on the percentage mortality of H. armigera. MNH-886 larvae showed the highest mortality percentage when fed on leaves that were harvested 30 DAP (days after planting). When larvae were fed on 60 and 90 DAP leaves on CIM-598 and IR-1524, the mortality rate was greater. However, AA-802 had the highest death rate when larvae were fed on 120 DAP leaves. The variety with the highest death rate was CIM-598. When H. armigera consumed 60 DAP leaves, the greatest overall mortality was noted. The plant-toxin interaction in cotton varied depending on a number of physiological changes in plants. Regardless of plant age or variety, the highest rate of mortality of H. armigera larvae was seen after feeding 48-hour of treatment or feeding.