Temporal Expression of Cry1Ab/c Protein in Bt-Cotton Varieties, their Efficacy against Helicoverpa armigera (Lepidoptera: Noctuidae) and Population Dynamics of Sucking Arthropods on Them.

Current study focused on expression profiling of locally bred Bt-cotton varieties through ELISA and were tested for their efficacy against survival of Helicoverpa armigera in control environment. The population dynamics of five sucking arthropods; whitefly, jassid, aphid, thrips and mites, along the growing season was also monitored and correlated with different meteorological factors. Expression levels of insecticidal protein CrylAb/c were found to vary significantly (P<0.05) among varieties and across different sampling dates. The highest mean expression was recorded in GN-31 and Sitara-008 and the lowest in FH-113 and MG-6 while across sampling dates the highest mean expression was recorded at 30 days after emergence (DAE) which decreased along the season with lowest mean at 120 DAE. A critical expression level of Cryl Ab/c in leaves was found at 770 ± 25 ng g[sup -1], for 95% control of the target insect pests. Sucking pest population was found to be variable among both the cultivars and the sampling dates. A positive correlation was found between rain/ humidity and sucking arthropods population in the sampled cotton plots. © 2014 Friends Science Publishers [ABSTRACT FROM AUTHOR]