Meiotic abnormalities affect genetic constitution and pollen viability in dicots from Indian cold deserts.

Background: Meiotic abnormalities lead to morphological and genetic variations which caused not only to evolution but also intraspecific reproductive barriers. During present study of detailed meiotic course in dicotyledonous plants sampled from Indian cold deserts, various meiotic abnormalities have been detected. For this, the plant materials fixed in Carnoy's fixative and studied detailed meiotic course by standard squash method in 1% acetocarmine. Results: Meiotic abnormalities have been presently detected in 71 species which include multiple associations in diploids (Achillea millefolium L.), multivalents and univalents in polyploids (4 species), cytomixis (40 species), chromosome stickiness (20 species), nonsynchronous disjunction of bivalents (32 species), interbivalent connections (15 species), synaptic mutants (2 species), syncyte meiocytes (2 species), abnormal spindles (7 species), and fusion of pollen grains (1 species), laggards and chromatin bridges, hypo-, hyperploid PMCs, monads, dyads, triads, tetrads with micronuclei and polyads. Conclusions: Consequently, variable sized apparently fertile pollen grains and considerable amount of sterile pollen grains are resulted as end products which lead to different genetic constitution (aneuploids and polyploids) and curtailed sexual reproductive success in these species. [ABSTRACT FROM AUTHOR]