Environmental Control of Fruitbody Development In Boletus Rubinellus in Axenic Culture

SUMMARY

The influence of temperature, humidity, aeration and gas composition, light and nutrition on fruitbody development in Boletus rubinellus was studied. The fruitbody index was used to quantify the degree of fruitbody maturation. Fruitbody development required 4–6 weeks depending on the conditions used. Fruitbody initiation occurred at 17–29 C, and maturation from 22–25 C. In chambers supplied with continuously changing, humidified air, stipe development and pileus formation occurred only in the light. Primordia were initiated in the light or in the dark in aerated or unaerated chambers, but they developed further only in aerated chambers in the light. Increased carbon dioxide concentration prevented stipe elongation and appeared to be the cause of stipe inhibition in unaerated cultures. Fruitbodies were produced on a defined medium solidified with purified agar. In culture, regeneration, the dependence of fruitbody induction on the presence of carpophore tissue, does not explain the ability of B. rubinellus to form fruitbodies, but the small size of the carpophore may have a bearing on its fruiting ability.