2011 Volume 80 Issue 1 Pages 49-58
Glutinous rice (GR) was planted in 63-69 pots (2-3 plants/pot) on the leeward of non-glutinous rice (NGR), at a distance of 2, 26, 150 and 300 m in 2006 and 150, 300, 450 and 600 m in 2007. Sterility of GR treated with cool-water irrigation during ear formation (CWT) were 25 and 43% in 2006 and 2007, respectively, while that of non-treated GR (control, set only in 2007) 26%, and that of non-treated NGR 10-13%. Using xenia seeds of GR the variety of pollen donor was determined by polymerase chain reaction analysis. The out-crossing rate (OCR) was 1.136, 0.529, 0.068 and 0.024% in 2006, and 0.084, 0.023, 0.012 and 0.035% in 2007, and that in control plants 0.017, 0.014, 0.002 and 0%, in order of short distance. Thus, the OCR was higher in CWT with higher sterility than in the control irrespective of the distance in 2007. The longer the distance, the lower the OCR except for the plants in CWT in 2007. However, out-crossing was found even at 600 m, and this is explained as follows. The duration of heading and pollen scattering in GR and NGR overlapped sufficiently. The sterility was much higher in GR than in NGR. The field area of NGR was large (10.3 ha). The mean wind velocity from NGR to GR during the flowering was high (3.6-4.0 m/s).
