DNA content, chromosome composition, and isozyme patterns inPlantago L.

Retrospective as well as recent records on DNA content, chromosome composition, and isozyme variation were analyzed critically to trace the evolution of species of the genusPlantago. Both in vivo as well as in vitro data were taken into consideration. The species withX 6 were considered to be ancestral, whereas those withX= 5 were considered to be more advanced. The cultivated species withX= 4 was thought to be a derivative ofX = 5. The data on isozyme variation supported the findings derived from DNA and chromosome composition.