Abstract
A comparative RAPD analysis was performed on apomictic and sexual lines of guineagrass to identify their mode of reproduction. The lines tested included apomictic autotetraploid(2n=4x=32)cultivars "Natsukaze", "Natsuyutaka" and "Ku 5954" and the tetraploid sexual line "Noh PL 1". In addition, diploid(2n=2x=16)sexual line "GR 297" and three progeny of a triploid hybrid(2n=3x=24)were also evaluated. Of the 16 primers(Operon RAPD decamer primers)tested, eight produced band patterns which clearly discriminated between the apomictic and sexual line. The three lines of apomictic origin displayed different patterns;however, the data derived from individual plants within the three lines were identical. In contrast, individuals belonging to the two sexual lines consistently showed different patterns within and between the two lines. Three progeny of a triploid hybrid had identical RAPD banding patterns through the experiment. Thus, the triploid hybrid was predicted as apomictic propagation. Microscopic embryo sac analysis confirmed the mode of reproduction in the genotypes tested as revealed by RAPD banding patterns. This research suggests that RAPD analysis is suitable for the identification and discrimination of apomictic and sexual lines of guineagrass.
