Silver nitrate influences in vitro root formation in Decalepis hamiltonii Wight and Arn.

Effects of AgNO3 on root formation were examined in vitro using axillary bud cultures of Decalepis hamiltonii. In the case of a medium comprising of MS salts with indole 3-acetic acid (IAA) (0.5 mg l–1), poor rooting was observed and root emergence did not occur until after 25 days. The resultant roots were stunted. Addition of 40 μM AgNO3 improved root initiation and elongation. The promotive effects of AgNO3 on rooting may result from inhibition of ethylene action. Upon addition of ethephon to the rooting medium, excessive callusing was observed in explants in all the treatments. Addition of 40 μM AgNO3 to ethephon-containing medium resulted in improvement in root initiation and elongation. Ethylene production was monitored in all the treatments with IAA/AgNO3/ethephon and it was observed that the treatment with IAA (0.5 mg l–1) alone showed a greater increase in ethylene production when compared with AgNO3, ethephon and their combinations.