Germination behaviour of Rauwolfia Serpentina benth. in association with vam fungi

Freshly harvested seeds of Rauwolfia serpentina benth. after sun drying failed to germinate in laboratory at 25ºC in light or in dark. Treatments like acid scarification with sulfuric acid, de-coating by sodium hypochlorite and alternate temperature alone or in combination also failed to cause germination. Imbibition percentage (weight basis), however, increased over control. Scanning Electron Microscopic studies of seed coat revealed that pretreatments were differentially effective in opening the hilum and suture region, the effectiveness being maximum in acid scarification. Fresh seeds showed 15% germination when they were associated with vesicular arbuscular mycorrhizal (VAM) fungi. Germination percentage increased when seeds were exposed to alternate temperature (35%), sodium hypochlorite (60%) and sulfuric acid (80%) pretreatment in association with VAM fungi. Initiation of germination also accelerated with these treatments. Scarification treatment increased leaching of electrolyte, soluble carbohydrate and amino acids, which probably act as chemical messenger, that assists in coordinating the formation of mycorrhiza.