Dietary effects of cotton tissue expressing germin like protein on beet armyworm (Lepidoptera: Noctuidae) growth, survival and pupation

Transgenic cotton lines that ectopically express a cotton germin-like protein (GLP) were screened for resistance/tolerance factors to the beet armyworm (BAW) Spodoptera exigua (Hübner) via feeding assays. The number of BAW eggs that successfully hatched was not statistically different at 72 h after infestation for wild-type cotton plants (Gossypium hirsutum L. c.v. 'Coker 312') or plants of 4 independent transgenic lines (ABP-A, ABPB and ABP-C and ABP-D). However, the damage caused by these same larvae at 72 h was higher for 'Coker 312' and line ABP-D when compared to ABP-A, ABP-B and ABP-C transgenic plants. Larval live weights were also significantly higher for Coker 312 and ABP-D at 5, 7, and 14 d when compared to ABP-A, ABP-B and ABP-C. The percentage of larvae that successfully completed pupation was significantly higher for BAW larvae fed 'Coker 312' and ABP-D tissue compared to the other 3 lines. These feeding bioassays show the potential for using cotton germin like protein to improve resistance or tolerance for BAW attacking cotton.