Abstract
Sexually leproduclng plants (sexual plants) of guineagrass were screened by progeny tests for progressing cross breeding in this apomictic species. Two hundreds and thirty four plants of 86 guineagrass accessions were self-pollinated by bagging and/or open-pollinated. Their progenies were space-planted in plot of ten or twelve plants in these tests. Hairiness on eight different organs and distinct changes of morphological traits were observed for scoring the variability within progeny. Two criteria of varia-bility, viz. number of plant types and number of plants belonging to the predominant plant type within a progeny, were adopted. Plant type is a group of plants in a progeny which showed the same or similar combination of scores given to the charac-ters. Determination of the mode of reproduction, sexual or apomictic, and estimation of the degree of sexual reproduction (sexuality) were made basing on the number of plant types and number of plants belonging to the predominant type. Out of 234 plants, 4 highly sexual plants and 2 Iowly sexual plants were isolated from 4 accessions. Sexuality of these 6 plants was ascertained by progeny test in the second generation. The isolated highly sexual plants produced highly sexual offsprings, non-segregating offsprings and a few or no lolvly sexual offsprings in their progenies. Lowly sexual platns produced lowly sexual offsprings and non-segregating offsprings. Chromosome numbers of sexual plants were counted in pollen mother cell or root-tip cell. Four highly sexual plants were classifled into one plant with 2n=32 chromosomes, two plants lvith 2n=16 chromosomes and one plant with 2n=18 chromosomes. Two 10wly sexual plants included one plant with 2n=32 chromosomes and one plant of unl.cnown chromosome number. Sexual plant with 2n=18 chromosomes was first dis-covered in the present studies. Prospect of utilizin*o' these sexual plants in combination with apomicts for breeding of this plant species lvas discussed
