Natural crossing in grain sorghum

Abstract

The percentage of natural cross-pollination in grain sorghum was investigated at Biloela Research Station, central Queensland, over a 2-year period. Dominant red-pericarp colour was used as a marked gene. There was 4·4% to 8·0% outcrossing of single white-pericarp coloured plants in a stand of red-pericarp plants and 2 · 9% to 8 · 0% outcrossing of a 6 metre row of white-pericarp plants in a red-pericarp stand. In most of the tests, the upper one-third of the panicle had a higher incidence of outcrossing than the lower two-thirds. In the remaining tests, there were no significant differences in outcrossing between portions of the head.