Abstract

Three different surface sterilization methods were evaluated using seeds andexcised embryos of cowpea, rice and sorghum as explants: Method 1: Ethanol alone in concentrations of 95, 90, 85 and 70% at different time intervals and observed at different days. Method 2: Locally produced bleaching solution (JIK® -Reckitt and Benckiser (Nig) Ltd) containing 3.5% Sodium hypochlorite) at different time intervals, observed at different days. Method 3 (The control): The routinely used two step sterilization procedure using 90% ethanol for 3 min followed by sodium hypochlorite 3.5% for 30 min. This is commonly used in most laboratories.However, neat concentration of the locally produced bleaching solution of JIK^® (-Reckitt and Benckiser (Nig) Ltd) containing 3.5% sodium hypochlorite was used instead of the pure sodium hypochlorite solution. Our results showed that Method 2 produced the highest reduction in bacterial and fungal contamination (0%) at time intervals between 20 - 45 min. The search for a simple, rapid and economical method of sterilizing explants for tissues culture, instead of the orthodox two-step -two reagent - technique, necessitated these experiments; we would, therefore recommend this technique due to its simplicity and economy.

Key words: Explant, surface sterilization, cowpea, rice, sorghum, JIK^®