Cytogenetic Studies in <i>Cynodon</i> L. C. Rich. (Gramineae)¹

Abstract

In a biosysteiriatic analysis of Cynodon over 700 interspecific and nearly 2,000 intervarietal hybrids were produced. C. barberi , C. arcuatus , and C. plectostachyus proved to be completely isolated from each other and the rest of the genus. C. aethiopicus could be crossed with C. dactylon and C. nlemfuensis , but with great difficulty. Hybrids between the remainder of the taxa could be produced more easily and the chromosome behavior of these hybrids is reported. In all crosses between diploid taxa, the most common configuration is nine pairs. The most common configuration in triploid hybrids is nine pairs and nine univalents regardless of the parentage. Chromosome pairing in tetraploid hybrids is variable. There is little or no genome differentiation among the species that can be crossed. The evidence is discussed with respect to a recent revision of the genus.