Radiation Studies with Sexual Yellow‐Anthered Dallisgrass, Paspalum dilatatum Poir

Abstract

Dormant seed of an erect, sexual, but highly uniform dallisgrass, Paspalum dilatatum Poir., ecotype were irradiated with gamma rays and neutrons in an effort to induce favorable changes in growth habit. Radiation caused extensive changes in morphology and growth characteristics and also resulted in severe seedling mortality and high sterility. Most of the mutants were inferior to untreated plants, but a few highly fertile, vigorous, decumbent mutants of potential value were recovered in the M2 generation.In general, prominent changes in growth characteristics were accompanied by chromosomal aberrations, reduced viability of male and female gametophytes, and low fertility. Abortion of the female gametophyte corresponded very closely to the reduction in pollen quality. Degeneration of sporogenous tissue was noted at all stages of megasporogenesis and embryo sac development, and there was no evidence of selectivity for a balanced megaspore within the linear tetrad.