Propagation of Rhizophora Species through Viviparous Hypocotyl Cuttings and Air Layering

Vegetative propagation protocols from viviparous hypocotyl cuttings and air layering were standardised for three species of Rhizophora viz., R. apiculata, R. mucronata and R. x hybrid. Hypocotyl cuttings treated with Indole Butyric Acid (IBA) at a concentration of 1500 to 2000 ppm gave better ischolar_main induction, growth response and number of ischolar_mains in all three species. The viviparous hypocotyls were cut into three equal portions (upper, middle and lower) and used in the experiment. The lower part of the viviparous hypocotyls including the ischolar_main portion responded better than the upper and middle portions. Air layers treated with 2000-2500 ppm of IBA showed good ischolar_main induction in R. apiculata and R. mucronata while a combination of IBA (500 ppm) and NAA (200 ppm) gave better response in the R. x hybrid. Rooted cuttings and air layers were transferred to the field after hardening in mist chambers for two months after the appearance of the ischolar_mains. Rooted cutting and air layers were established in the field nursery MGRCC (Mangrove Genetic Resource Conservation Centre) in Pichavaram with 83% survival.