Male Meiotic and Morphometric Analysis in the 2x and 4x Cytotypes in Arabis recta Vill. (Brassicaceae) from Cold Desert Regions of North-West Himalayas

摘要

The present communication reports the first record of intraspecific euploid cytotypes (2x, 4x) in Arabis recta from the cold deserts of North-West Himalayas in India. The study included the detailed male meiosis, microsporogenesis, pollen fertility and morphometric parameters in the accessions of 2x and 4x cytotypes. Both the diploid and tetraploid cytotypes exhibited normal meiotic behaviour characterized by normal chromosome pairing, regular segregation of chromosomes and nearly cent percent fertility. The 2x and 4x cytotypes grow under similar extreme cold desert conditions on mountain slopes between 2800 to 4500m altitudes. The 4x plants grow much taller and possessed much larger sized pubescent leaves. The two cytotypes could also be differentiated on the basis of size of stomata and pollen grains, which are significantly larger in the 4x compared to the 2x.