Introgressing New Sources of Sugarcane Borer Resistance: Can Theory Become Practice?

Authors: White, William; Tew, Thomas; Richard Jr, Edward

Submitted to: International Society of Sugar Cane Technologists Proceedings
Publication Type: Proceedings
Publication Acceptance Date: 2/6/2007
Publication Date: 7/30/2007
Citation: White, W.H., Tew, T.L., Richard Jr, E.P. 2007. Introgressing New Sources of Sugarcane Borer Resistance: Can Theory Become Practice? Proceedings of the International Society of Sugar Cane Technologists. 26:850-853.

Interpretive Summary: Two moth stemborers, locally known as the sugarcane borer and Mexican rice borer, are the most damaging insects of sugarcane in the continental U.S. Planting sugarcane varieties resistant to these stemborers is a viable option to expensive and potentially environmentally disruptive insecticide applications. Unfortunately, resistant varieties frequently yield less than susceptible varieties as those plant characteristics imparting resistance often cause the plant to have lower yields. We conducted research investigating the likelihood of finding new resistance traits, traits not associated with lower yields, in sugarcane ancestors and then investigated the feasibility of transferring that resistance to a high yielding commercial variety. We were successful in identifying stemborer resistance in sugarcane ancestors, but found that this resistance could be lost by the time that commercial varieties are available. This research is still very encouraging, however, as it points researchers into a direction that stemborer resistance is likely to be found and aids plant breeders in developing a breeding scheme that will insure the capture that resistance in commercial varieties. Ultimately, farmers and the non-farming public will benefit from this research by having sugarcane varieties to plant that produce high yields without having to be protected with pesticides.

Technical Abstract: The stemborer, Diatraea saccharalis (F.), is an important insect pest of sugarcane in Louisiana. Plant resistance is an effective control tactic; however, resistant varieties frequently yield less than their susceptible counterparts as those traits associated with resistance can be associated negatively with sucrose yields. New mechanisms of resistance may solve this dilemma and sugarcane progenitors may provide a source for these mechanisms. We first (Phase 1) investigated the likelihood of identifying new sources of stemborer resistance from sugarcane progenitors and then the feasibility of transferring that resistance into commercial backgrounds (Phase 2). In Phase 1 we evaluated 39 Saccharum spontaneum clones by laboratory bioassay and found a wide range in resistance as measured by reduced larval weight (from 0.0 to 79.0mg; P < 0.001). In Phase 2, conducted in the field, we evaluated 20 BC3 progeny derived from a resistant and a susceptible S. spontaneum identified in Phase 1. There was little difference between the two population means for percent bored internodes (R = 19% ± 1; S = 21% ± 1). Results indicated that progenitors could provide a source of resistance to the stemborer, but there is the potential for having this resistance diluted before commercial phenotypes become available.