Species Relationships inDichanthiumV. The Diploid Species

Abstract

Diploid species of Dichanthium are genetically isolated from each other. Diploid races of the more commonly tetraploid species D. aristatum, D. annulatum and D. caricosum could be crossed with tetraploid D. annulatum. Hybrids were also produced between the strictly diploid species D. panchganiense and tetraploid D. annulatum. Chromosome homology appeared to be absent between the basic genomes of D. annulatum and D. panchganiense, while some degree of homology seemed to exist between the genomes of tetraploid D. annulatum and the diploid races of D. aristatum and D. caricosum. Morphological data indicated that the Indian diploid species D. panchganiense and D. maccannii are closely related. Similarly the Australian diploids D. humilius, D. sericeum, D. setosum and D. superciliatum form a morphologically related group.