Location: Wheat, Sorghum and Forage ResearchTitle: Rate of in situ Shattercane x Sorghum Hybridization) Author
Submitted to: Weed Science Society of America Meeting Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 9/4/2009
Publication Date: 2/7/2010
Citation: Schmidt, J., Lindquist, J., Bernards, M., Pedersen, J.F. 2010. Rate of in situ Shattercane x Sorghum Hybridization. Abstract. Weed Science Society of America, Feb. 7-11, 2010, Denver, CO. Interpretive Summary:
Technical Abstract: Sorghum (Sorghum bicolor subsp. bicolor) can interbreed with its close weedy relative shattercane (S. bicolor subsp. drummondii). The introduction of traits from sorghum into a shattercane population could contribute to the invasiveness of the wild shattercane population. An in situ experiment was conducted to determine the potential for pollen-mediated gene flow from grain sorghum to shattercane. Shattercane with juicy midrib (dd) was planted in a soybean field in concentric arcs at varying distances from a sorghum pollen source with dry midrib (DD). The arcs were placed so that prevailing winds would carry pollen from the sorghum to shattercane. Shattercane panicles in anthesis during sorghum pollen shed were tagged and seeds were collected from those shattercane panicles. Progeny were evaluated using the dominant phenotypic marker to determine outcrossing rate. Outcrossing was greatest (3.6±0.06%) for shattercane placed within the source and generally declined as distance increased. 101 of the 105 panicles evaluated at =10m exhibited outcrossing with the highest outcrossing individual having 10.2%. Outcrossing was noted in 9 of the 73 panicles grown at the farthest distance evaluated (200m) with the highest outcrossing individual having 2.4%. Results indicate that genes from sorghum and any associated traits could be introduced into shattercane populations at distances of at least 200m. Two of the 307 panicles evaluated (both 40m from source) had outcrossing rates greater than 40%. It is hypothesized that this might be due to environmental or genetic factors inducing protogyny or male sterility. Further tests are being conducted to examine the cause.