Segregation distortion affected by transgenes in early generations of rice crop-weed hybrid progeny: Implications for assessing potential evolutionary impacts from transgene flow into wild relatives Genotypic Mapping Using RFLP Markers on Doubled Haploids Derived from a Cross Between indica and japonica Rice Distorted Segregations of RFLP Markers and Their Distribution on Chromosomes in an indica/japonica F2 Population of Rice (Oryza sativa L.)