Relative DNA content in diploid, polyploid, and multiploid species of Paspalum (Poaceae) with relation to reproductive mode and taxonomy

GALDEANO F.; URBANI M.H.; SARTOR M.E.; HONFI A. I.; ESPINOZA FRANCISCO; QUARIN C.L.

JOURNAL OF PLANT RESEARCH

SPRINGER TOKYO

Lugar: Tokyo; Año: 2016 vol. 129 p. 697 - 710

0918-9440

Abstract It is generally accepted that polyploids havedownsized basic genomes rather than additive values withrespect to their related diploids. Changes in genome sizehave been reported in correlation with several biologicalcharacteristics. About 75 % of around 350 species recognizedfor Paspalum (Poaceae) are polyploid and most polyploidsare apomictic. Multiploid species are common withmost of them bearing sexual diploid and apomictic tetraploidor other ploidy levels. DNA content in the embryo andthe endosperm was measured by flow cytometry in a seedby-seed analysis of 47 species including 77 different entities.The relative DNA content of the embryo informed thegenome size of the accession while the embryo:endospermratio of DNA content revealed its reproductive mode. Thegenome sizes (2C-value) varied from 0.5 to 6.5 pg and for29 species were measured for the first time. Flow cytometryprovided new information on the reproductive modefor 12 species and one botanical variety and supplied newdata for 10 species concerning cytotypes reported for thefirst time. There was no significant difference between themean basic genome sizes (1Cx-values) of 32 sexual and45 apomictic entities. Seventeen entities were diploid and60 were polyploids with different degrees. There were noclear patterns of changes in 1Cx-values due to polyploidyor reproductive systems, and the existing variations are inconcordance with subgeneric taxonomical grouping.