Effect of seed heteromorphism and seed collection time on germination of the medicinal plant Centella asiatica (L.) Urban in sub-tropical plains of north India

Abstract

Centella asiatica (L.) Urban (Family- Apiaceae) is a high-value medicinal plant that contains asiatic acid, asiaticoside, madecassic acid and madecassoside, etc. It is traditionally used as a wound healer and in various skin related diseases. It is propagated through stem cuttings or seeds. It has been observed that the seeds of this medicinal plant show considerable germination in laboratory conditions, whereas its germination is very low under natural environmental conditions. In the present study, efforts are made to distinguish between the viable and non-viable seeds of Centella asiatica (L.) Urban as the same plant bears seeds of different shapes and sizes. Colour thus may show seed heteromorphism. Seeds were collected at three time-frames; before the rain, at the initiation of rain, and during good rains in north India’s sub-tropical climate, and were classified among seven different categories based on shape, size and color. Results indicated that maximum germination (24%) was observed in the seeds, that were dark brown, swollen and collected during the initiation of rains. The lowest germination was observed in light brown-colored seeds. In addition, it has also been observed that in some categories (yellow-coloured seeds with the flattened shape) there was no germination.