Cytotype distribution in a diploid/hexaploid contact zone in Aster

Cytotype distribution in a diploid/hexaploid contact zone in Aster

Cytotype dis­tri­bu­tion in a diploid/hexaploid con­tact zone in Aster

A know­ledge of cyto­type diversity and dis­tri­bu­tion pat­terns is import­ant in under­stand­ing evol­u­tion­ary dynam­ics of diploid–polyploid con­tact zones. Castro et al. study large– and small-scale cyto­type dis­tri­bu­tion pat­terns and repro­duct­ive vari­ables in the only mixed-ploidy pop­u­la­tion so far detec­ted of the diploid–hexaploid Aster amel­lus aggreg­ate. They find a com­plex con­tact zone mostly com­posed of single-cytotype pop­u­la­tions grow­ing in par­apatry in sev­eral areas. Both primary and sec­ond­ary con­tacts are pos­sible, sup­port­ing an auto­poly­ploid ori­gin of the aggreg­ate. They observe no signs of cyto­type hybrid­iz­a­tion, and sug­gest that minor­ity cyto­type exclu­sion may be one of the mech­an­isms driv­ing the pre­val­ence of the single-cytotype populations.

Annals of Botany Office.

The Annals of Botany Office is based at the University of Leicester.