Cytogenetics of Polyploids

III. Dauermodifications in Ageratum conyzoides Linn

Abstract

Plants of tetraploid Ageratum conyzoides exhibiting dauermodifications were obtained by treating the seeds with aesculin. Abnormalities in morphological and cytological characters were observed. These gradually diminish in subsequent generations and finally disappeared in the 4th generation. Dauermodification in A. conyzoides seems to be controlled by genes as well, rather than by cytoplasm alone. Genes controlling anthocyanin pattern, cytological behaviour and erectness seem to be linked. An origin of cross bridges has been attempted.