Chromosome Number in Cynodon dactylon in Relation to Ecological Conditions

Populations of Cynodon dactylon (L.) Pers. were collected fromthree habitat types (roadsides, lawns and paddy-fields) withineach of five climatic regions (arid, dry, intermediate, wetand hill country) in Sri Lanka. Further populations were collectedfrom forests and grasslands in the hill country. Most populations contained only tetraploid plants (2n = 36),but populations from roadsides and lawns in the wet region,and from forests in the hill country, contained only diploidplants (2n = 18). Populations from paddy-fields in the wet regioncontained both tetraploid and diploid plants. No triploid plantswere found in any environment, despite the fact that C. dactylonpredominantly reproduces vegetatively by both stolons and rhizomes.Soil acidity seems to be the main factor determining the distributionof the two cytotypes.Copyright 1995, 1999 Academic Press Cynodon dactylon (L.) Pers., chromosome number, ecology, habitat, climatic region