2016 Volume 81 Issue 2 Pages 161-168
The present population-based cytological studies were conducted in Angelica glauca collected from the northwestern Himalayan region of India. For the first time we report the occurrence of various meiotic abnormalities viz. cytomixis, chromosomal stickiness, unoriented bivalents, laggards, bridges and other spindle irregularities in the species that exist at diploid level (2n=2x=22). The phenomenon of cytomixis (17.35%), involving the transfer of chromatin material between 2–4 adjacent pollen mother cells (PMCs) during male meiosis through broad and narrow cytomictic channels, was observed from early prophase stages to tetrad stage. Cytomixis results in the formation of hypo-, hyperploid and enucleated PMCs. The severe chromosomal stickiness restricts chromosome separation during anaphase. Further, the spindle abnormality produces monads, dyads, triads, polyads and micronuclei in sporads during microsporogenesis. All these abnormalities affect the pollen grain size and reduce the pollen fertility (64.23–84.25%) in such populations. In the present paper, the consequences of cytomixis, chromatin stickiness and other anomalies have been discussed in detail for different populations sampled from different altitudes.
