STUDY ON THE EFFECT OF LOCAL STARCH AND BAMBARA GROUNDNUT FLOUR AS SUPPLEMENTS ON THE PRODUCTION OF SCLEROTIUM IN Pleurotus tuber-regium (Fr.) Sing.

ABSTRACT

Pleurotus tuberregium (Fr.) Sing. is a tuberous wild species of white rot basidiomycete which is edible and possess medicinal properties. It is also known as the “King Tuber Oyster Mushroom” and it is the only Pleurotus species which produces true sclerotium. The objective of this study was to investigate the effect of locally made starch powder and Bambara groundnut flour as supplements on substrate to produce sclerotium in Pleurotus tuberregium and the effect of the same supplements on the vegetative growth of the mushroomon media in petri dishes. Sawdust of Bombax buonopozense was used as substrate and was supplemented with the two supplements separately at varying levels of 0 %, 2 %, 4 %, 6 % and 8 %. The results obtained revealed that mycelia growth on the substrate was very slow and only few bags attained a colonization level of between 25 – 50 %. 8 % starch attained a colonization level of 50 % after 67 days. However, mycelial growth rate on starch supplemented substrate was higher than on Bambara groundnut flour supplemented substrate. 8% starch attained a colonization level of 50 % after 67 days .No sclerotium was formed in any of the bagged substrates. A follow-up experiment was done to determine the vegetative growth of the mushroom on media prepared using the sawdust extract with the same supplements at same concentrations. The results obtained after 7 days showed that both supplements supported mycelia growth of the mushroom. In line with the observation made from the bagged substrate, mycelial growth rate on starch supplemented media gave the highest growth rate (8 % = 12.08±0.65 mm/day) than Bambara groundnut flour supplemented media (8 % level = 12.00±0.21 mm/day). However, the mycelia biomass obtained from the Bambara groundnut flour supplemented media produced the highest biomass (6 % = 307.83±58.69 mg) was higher starch supplemented media (2 % = 292.70±53.55 mg). This work shows that locally available supplements can be used to enhance the growth of Pleurotus tuberregium in Nigeria.