Chromosome Number, Meiosis and Pollen Fertility in Vicia rigidula Royle and V. tenera Grah. From Cold Desert Regions of India

We have recorded the meiotic chromosome counts in 2 species, Vicia rigidula (n=12) and V tenera (n=7) from the cold desert region of Kinnaur district of Himachal Pradesh (India). V rigidula which exists at tetraploid level (x=6) and depicts the phenomenon of cytomixis involving chromatin transfer in 6.52% of the observed pollen mother cells (PMCs) during different meiotic stages. 3.43-12.20% of PMCs also show non-synchronous disjunction of a few bivalents, laggards and chromatin bridges during anaphases/telophases, and micronuclei and included micronuclei in tetrads. Products of such aberrant PMCs result in the formation of sterile/unstained pollen grains and fertile/stained pollen grains of variable sizes. The meiotic course in V tenera, which is diploid (x=7), depicts normal meiotic behaviour in the majority of the PMCs. Only a few PMCs (0.20-1.20%) depict some meiotic disturbances during anaphases resulting in the formation of 6.00-7.20% sterile/unstained pollen grains.