ARS | Publication request: Gene Flow from Cultivated Sorghum to Weedy Relatives

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: April 2, 2010
Publication Date: June 21, 2010
Citation: Pedersen, J.F., Schmidt, J.J., Lindquist, J.L., Bernards, M.L. 2010. Gene Flow from Cultivated Sorghum to Weedy Relatives. Meeting Abstract presented at the 2010 Australian Summer Grains Conference, Gold Coast, QLD, June 21-24.

Technical Abstract: Sorghum (Sorghum bicolor) is predominately sexually self-compatible, but may vary in extent of outcrossing due to panicle morphology and proximity to other compatible individuals. Using male-sterile lines and field designs not typical of production agriculture, previous researchers have documented the ability for sorghum to cross at considerable distance from a pollen source. Our research documents in situ outcrossing of self-fertile shattercane (S. bicolor subsp. drummondii) growing in a soybean (Glycine max (L.) Merr.) field at varying distances from a cultivated sorghum pollen source and flowering in synchrony with that source. Outcrossing was 3.6% for shattercane planted within the cultivated sorghum and generally declined to 0.09% at 200 m. Progeny from 101 of the 105 panicles evaluated at =10m contained outcrossed seed. Results from a separate study on the fitness of shattercane x cultivated sorghum hybrids indicate that the relative fitness of shattercane x cultivated sorghum F1 hybrids may be equal to or greater than the wild shattercane parent. Studies are planned to investigate fitness of F2 populations, and to model gene flow in shattercane populations. These results will be important in developing management strategies for sorghum with transgenic or herbicide resistance traits.