Seed germination responses of the medicinal herb Centella asiatica.
The effect of several environmental factors on germination of medicinal herb Centella asiatica was investigated. Freshly harvested seeds of C. asiatica did not germinate even after gibberellic acid (GA3) treatment and exposure to different treatments with light qualities, while two-three months old seeds exhibited germination (82%) without pre-treatment at warm environment (25-30°C). GA3 treatment induced germination by two weeks earlier than in control. Germination was significantly (p=0.001) higher in red and white light than in blue and far red light. In addition, germination of C. asiatica was sensitive towards the salt stress and was significantly inhibited at 6500 ppm NaCl. The leaf leachates from invasive weeds Chromolaena odorata, Ageratum conyzoides, Parthenium hysterophorus and Xanthium strumarium showed inhibitory effects on seed germination of C. asiatica. Parthenium hysterophorus had significant effect (p<0.001) on seed germination. These data contribute for the establishing of an efficient protocol for C. asiatica cultivation.