BIOLOGICAL AND TOXICANT STUDIES WITH THE DRY ROT FUNGUS SERPULA-LACRYMANS AND NEW STRAINS OBTAINED BY BREEDING

TVvo isolates of Serpula lacrymans were bred via monokaryons to new strains.The 19 fungi wcrc invcstigatcd regarding the effects of tcmpcraturc and pH-value, thc clcctrophorctic pattcrn of mycclial protcins, the decay ability of wood and the toxic limit in chcmically trcatcd wood.Thc dikaryotic mycelia of thc parcntal strains and thc hybrids had clamp conncctions and no oidia, monokaryons oidia and no clamps. Dikaryons grew fastcr than monokaryons. Dikaryons were inhibitcd by 28°C and monokaryons by 31 °C, which is relevant for thc idcntification of the spccics by tempcraturc. AI) strains startcd growth at initial pH-valucs of 2.5 to 7.3 and acidificd thcir mcdia to pH 1.7 to 3.7. SDS-polyacrylamidc gel elcctrophorcsis of the intracellular proteins revealcd a pronounccd homogcncity among thc fungi, which can bc uscd to detect 5. lacrymans evcn in its monokaryotic condition. Dikaryons produccd 32% wcight loss of wood samplcs and monokaryons 28.5%.Thc toxic limit of chcmically trcatcd Scots pinc sapwood samplcs was 0.37 to 0.62 kg of borax per m3 of wood for thc dikaryons and 0.62 to 0.86 kg/m3 for the monokaryons. The increased tolcrancc of toxicants by the monokaryons of S. lacrymans may bc important to the cfficicncy of wood prescrvation in practicc. © 1990, Walter de Gruyter. All rights reserved.