Cytology of Obligate Sexual Plants in Panicum maximum Jacq. and Their Use in Controlled Hybrids1

We isolated 18 obligate sexual plants of guineagrass (Panicum maximum Jacq.) from 2 plant introductions, PI 277922 and PI 277946, by analysis of morphological variation and cytological studies. Megasporogenesis and embryo sac development was typical of the Gramineae family. Sixteen controlled crosses involving 10 sexual plants ✕ robust short day apomictic plants produced 156 progenies. Fifty‐nine of the progenies were hybrids. The inheritance data, based upon progeny of selfed sexual plants and sexual ✕ apomictic hybrids indicated that sexuality is dominant. Sexuality appears to be controlled by at least two loci and conditioned by a dosage effect of two or more dominant alleles. This research demonstrates that it is possible to release the “stored” variability in this apomictic species through controlled sexual ✕ apomictic hybrids.