MEIOTIC BEHAVIOUR IN TWO TRIPLOIDS: ERIGERON ANNUUS AND EUPATORIUM ADENOPHORUM (ASTERACEAE)

ABSTRACT

The present study shows the meiotic behaviour in two species of Asteraceae family. Erigeron annuus (2n=27) and Eupatorium adenophorum (2n=51) are triploid (i.e. 3x based on x=9 and x=17, respectively) appear to be apomictic in nature due to the presence of highly abnormal meiotic course and high pollen sterility but with normal seed setting. Meiosis in these species is characterized by the formation of many univalents and trivalents with a few bivalents. Anaphases and telophases are highly abnormal with the formation of many laggards and micronuclei during microsporogenesis. Cytomixis is also a common phenomenon noticed in all Eupatorium adenophorum populations. Pollen sterility varies from 40-71%. Both the species are widespread in nature and grow as weeds certainly reproduce through asexual means.

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