Effects of Osmotin II over Expression in Transgenic Cotton on Cotton Aphid (Aphis gossypii) Reproduction and Colonization

Cotton that has been transgenically modified to over express the protein osmotin was evaluated for resistance to cotton aphid, Aphis gossypii. Life table studies conducted in the growth chamber indicated that aphids on cotton over expressing osmotin had a slightly lower natural rate of increase and a shorter longevity than those on a non-trangenic isoline. These data suggest that antibiosis is the mechanism of resistance.  Field studies were similar to the growth chamber studies. Plants with amplified osmotin expression tended to exhibit slightly fewer aphids per plant than the non-transgenically modified cultivar.  Although the aphid resistance exhibited was insufficient for preventing a treatable aphid population, it did indicate that further refinement might be applicable.