Cytological investigations in the Setaria sphacelata complex

Abstract

A cytological study of a wide range of strains of the Setaria sphacelata complex showed that diploid, tetraploid, pentaploid, hexaploid, octoploid, and decaploid races occur within the species complex. In addition, a number of plants had one or more (rarely up to 1.5) extra chromosomes which were probably B-chromosomes. No variation was recorded in the number of B-chromosomes in different root tips from the same plant, but different plants from the same strain frequently had differing numbers of B-chromosomes.

Breeding problems arising from the cytological complexity of S. sphacelata are discussed.