抄録
1. The hybridization was carried out. amohg three species of Digitaria, and F1 seeds were obtained from D. ciliaris PERS. (2n=54) X D. ischaemum MUHL. (2n=36). The average crossability was about 28% in two years. 2. Although the F1 seeds were smaller than the mother seeds, and the number of days necessary for germination was irregular and larger than that of the parents, their rate of germination was about 66%No viable seeds were obtained in the reciprocal cross. 3. As the F1 plants were not vigorous, many of them died in the younger stage owing to the high temperature of the midsummer. The growth of F1 plants was poor as compared with that of the parents. Many of the morophological characters of F1 jwere resembling with those of the mother plant. 4. F1 plants were almost cornpletely pollen sterile with 0.26% of apparently normal pollen, and the anther did not dehisce. Therefore, no F2 seed was obtained by self, open and back cross pollinations.
