Isolation of monospores of P.ostreatus and P.djamor for interspecific hybridizationand effect of temperature on dikaryotics

Oyster mushroom (Pleurotus spp.) commonly called as Dhingri in India, is one among the commercially cultivated mushrooms throughout the world and stands second in world production.However, cultivated mushrooms face problems like loss of genetic diversity and strain degeneration.Hence, there is an increased demand for the development of new and improved strains with high production and better growth attributes.The present study was conducted to improve the strain of Pleurotus species by interspecific hybridization through crossing single spore cultures.Pleurotus djamor is an early yielding pink coloured oyster mushroom having leathery texture and low biological efficiency (BE).It was crossed with the high yielding, Pleurotus ostreatus, which requires comparatively more days for primordial initiation.The experiment was conducted during 2021-2022 to find out the monokaryotic isolates of P. ostreatus (PO)and P. djamor (oyster pink or OP) for its dikaryotization with the help of rapidity in the growth performance.Seventeen monokaryotic cultures of P. ostreatus and twenty monokaryotic cultures of P. djamor were isolated by spore print, serial dilution and hyphal tip fragmentation techniques.Seventeen and twenty monokaryotic isolates of P. ostreatus, and P. djamor respectively were grown on Malt Extract Agar media (MEA) for testing their rapidity in radial growth.After the selection of monokaryotic isolates, interspecific hybridization was done between the monokaryotic and the dikaryotic culture was again tested in malt extract agar media under various temperature (24 0 C -32 0 C) to checktheir growth performance.In MEA media, the highest AUMGC monokaryotic isolates viz.PO5M, PO6M PO7M for P.ostreatus ,OP1M,OP10M,OP11M,OP15M,OP16M,OP19M and OP 20 M forP.djamor(oyster pink/OP) was finally selected for hybridization.Among the sixty-two dikaryotic cultures tested at 24 0 C -32 0 C .it was found that 30 0 C was best for all isolates but from sixty-two isolates, thirty-three dikaryotic isolates were able to grow at 32 0 C, which may be indicating the differences in tolerance of high temperatures.