ARS | Publication request: Prediction of cotton resistance to Helicoverpa armigera based on the percent (+)-gossypol in mature seed

Submitted to: Asian and Australasian Journal of Plant Science and Biotechnology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: November 2, 2012
Publication Date: January 16, 2013
Citation: Uzbekov, V.V., Veshkurova, O.N., Stipanovic, R.D., Namazov, S.E., Salikhov, S.I. 2013. Prediction of cotton resistance to Helicoverpa armigera based on the percent (+)-gossypol in mature seed. Asian and Australasian Journal of Plant Science and Biotechnology. Special Issue 2. pp. 61-63.

Interpretive Summary: Cotton breeders are trying to develop plants with resistance to the cotton bollworm. Finding plant characteristics that help breeders identify those plants that might have enhanced resistance to the cotton bollworm would accelerate this breeding process. Part of the plants natural resistance mechanism to the bollworm is the production of a compound called gossypol. Gossypol exists in the plant as a mixture of what is referred to as (+)- and (-)-gossypol. Early studies showed that (+)-gossypol is less toxic to non-ruminant animals such as chickens compared to (-)-gossypol. Thus, breeding efforts have been directed at developing plants that contain a high (+)-gossypol to (-)-gossypol ratio. We now find a strong correlation between plants that have high levels of (+)-gossypol and resistance to the bollworm. No correlation was observed between the levels of (-)-gossypol or total gossypol to insect resistance. Thus, the high (+)-gossypol seed characteristic may allow breeders to select plants that are resistance to the bollworm based on the (+)-gossypol content in seed.

Technical Abstract: Various Uzbek commercial varieties were grown in the field and these were exposed to cotton bollworm (Helicoverpa armigera) larvae. A significant negative correlation coefficient (r = -0.89) and linear regression (Y = 109.69-5.26X) was observed between the concentration of (+)-gossypol in cotton seed kernels and boll damage. Significant regressions were not observed in similar comparisons with (-)-gossypol or with total gossypol concentrations. This characteristic was used as a phenotypic predictor to guide breeding efforts to increase resistance to H. armigera.