Ploidy level and nuclear DNA content of some accessions of water yam (Dioscorea alata) collected at Save, a district of central Benin

Abstract

Ploidy level and nuclear DNA content of some accessions 01 water yam (Dioscorea a/ala) collected at Save, a district 01 central Benin The nuclear DNA content and the ploidy levels of 43 acces sions of wat er yam (Dioscorea alata) collected at Save (a district of cent ral Benin) were determined by both conventional chromosome counts (from root tip cells) and flow cytometry. The great majority (42) of the acces sions had 40 chromosomes and a nuclear DNA content varying from 1.0 pg to 1.26pg (mean 2C value was 1.07 pg). One accession had 80 chromosomes wi th a DNA content of 2.12 pg. The ploidy levels (2Xand 4Xor 4Xand 8X) of the analyz ed indi viduals are discussed . These findings have important implications for yam breedin g in rela tion to yam gene tic resou rces .