Strobilanthes virendrakumarana Venu & P. Daniel karyotype was found to be a mixoploid one with 2n = 20+01B and reveals the karyotype formula as 2nsm()+18nm+01B. The plant is endemic to Southern Western Ghats of Kerala. The basic set of chromosomes was found to be x = 10. The plant shows mixoploidy with four different chromosome counts from hypoploid (10+01B), diploid (20 = 01B) and hyperploid chromosome complements (30+02B, 40+02B). The karyotype formula of hyperploid cell was 2nsm()+8nm+01B. In hypoploid cells with 30 and 40 chromosomes the resulted karyotype formula were 30nm+02B and 6M+34nm+02B respectively. The total chromosome length of diploid complement was 45.34 µm with an average chromosome length of 2.2 µm. The detailed karyomorphometrical analysis of the plant reveals that is a primitive one with symmetric karyotype. The presence of Bchromosomes in the genus Strobilanthes is reporting for the first time. Ploidy level changes may be due to the prolonged flowering periodicity of the plant which enables them to survive by propagating through vegetative mode.
Keywords: Strobilanthes virendrakumarana, karyotype, primitive, Bchromosomes, mixoploidy, polysomaty
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