Cytogenetic diversity of Elsholtzia ciliata benth. (Lamiaceae) from Kashmir Himalaya

Abstract

Our cytomorphological study of various populations of Elsholtzia ciliata (Lamiaceae) collected from high-altitude sites of Kashmir Himalaya revealed two euploid cytomorphotypes, diploid (n=8) and tetraploid (n=16), growing sympatrically but inhabiting two different habitats. This is the first report of tetraploid (4×) E. ciliata from the Indian subcontinent. We found the course of meiois to be normal in diploids, but tetraploid individuals showed chromosome and meiotic irregularities: cytomixis at early prophase I, stickiness at metaphase I, and chromosome bridges at anaphase I. In tetraploids, 23 of the 26 pollen mother cells observed at metaphase I showed 0-6 quadrivalents, suggesting that the tetraploid is a segmental allopolyploid. Microsporogenesis was also abnormal in tetraploids, showing the formation of triads. All these anomalies are conducive to lower reproductive potential (40.70%) in tetraploids than in diploids (90.50%). Significant morphological differences between the two cytotypes are presented. © Polish Academy of Sciences and Jagiellonian University, Cracow 2012.