Chromosomal Diversity in Some Species of Plantago (Plantaginaceae) from North India

The present study deals with the detailed cytomorphological analysis and meiotic chromosome behavior in three species (14 accessions) of genus Plantago, P. depressa (2n = 24, 24+0-1B, 36), P. major (2n = 12, 24) and P. lanceolata (2n = 12) from North India. Chromosome number n = 12 and 18 for P. depressa are worked out for the first time from India. The hexaploid cytotype with n = 18 is a new report to the world. These are observed with various meiotic abnormalities during microsporogenesis. Different accessions of all the species show meiotic irregularities in the form of chromatin stickiness, univalent and multivalent formation, early as well as late disjunction of bivalents, laggards, chromatin bridges, abnormal microsporogenesis, pollen sterlity and variable pollen size. A significant association of bivalents is observed in all the accessions of P. depressa and in tetraploid accession of P. major.