Suillus collinitus

Abstract: The organic acids composition of six wild edible mushroom species (Amanita caesarea, Boletus edulis, Gyroporus castaneus, Lactarius deliciosus, Suillus collinitus, and Xerocomus chrysenteron) was determined by an HPLC-UV detector method. The results showed that all of the samples presented a profile composed of at least five organic acids: citric, ketoglutaric, malic, succinic, and fumaric acids. Several samples also contained oxalic, ascorbic, quinic, and shikimic acids. In a general way, the quantitation of the identified compounds indicated that malic acid, followed by the pair citric plus ketoglutaric acids, were the main compounds in the analyzed species, with the exception of A. caesarea, in which malic and ascorbic acids were the most abundant compounds. The relative amounts and the presence/absence of each identified compound may be useful for the differentiation of the species.

Abstract: Vegetative inoculum of Amanita ovoidea (Bull.) Link and three isolates of Suillus collinitus (Fr.) Kuntze, as well as spore inoculum of Rhizopogon roseolus (Corda) Th. M. Fr. and S. collinitus, were evaluated for the production of Pinus halepensis Mill. in nursery and for the establishment of seedlings in a degraded gypsum soil. In nursery, most of the fungi significantly improved the height of seedlings and modified the accumulation of nutrients in needles. The percentage of ectomycorrhizas (ESR) per seedling ranged from 25 to 78%, depending on the fungi. One and 2 years after planting in the field, the survival of seedlings was significantly improved by inoculation with two isolates of S. collinitus and with spores of the same fungus. Inoculation with A. ovoidea had no significant effect on seedling survival, whilst R. roseolus caused a significant mortality of seedlings. Seedling height was significantly improved by inoculation with all fungi except R. roseolus and isolate CCMA-1 of S. collinitus. One year after planting, mycorrhization of control seedlings was negligible, and percentages of ESR were under 38% for the rest of treatments. In spring of the second year, seedlings in all treatments, including the control, became highly mycorrhizal (60-77% of ESR). Low ectomycorrhizal diversity (five morphotypes described) and seasonal variation on morphotype composition were detected 2 years after plantation. From a perspective of soil restoration management under limiting environmental conditions, nursery inoculation with selected fungi can be a key advantage for tree seedlings to surmount the initial transplant stress, assuring their establishment in the field. Our results emphasise the importance of selecting compatible fungal-host species combinations for nursery inoculation and sources of inoculum adapted to the environmental conditions of the transplantation site.

Abstract: An experiment was carried out to evaluate the growth of mycorrhizal Pinus halepensis seedlings planted in a semiarid soil amended with urban refuse in southeast Spain. Three fungal species were used: Pisolithus tinctorius, Rhizopogon roseolus, and Suillus collinitus. After 8 months, inoculated seedlings grown under controlled conditions did not differ significantly from controls with regard to plant height and nutrient assimilation. Other features such as root development and stem dry weight showed that the plants grew better in the absence of mycorrhizal inoculation. The mycorrhizal seedlings and the controls were planted in three experimental plots treated with urban refuse (0, 6, and 12 Kg m-2). After 1 year of growth under field conditions the results showed that the type of fungus inoculated significantly influenced P. halepensis development. This effect varied with the dose of urban refuse. Plant growth was encouraged by the application of refuse but only at the lowest dose. Under these conditions P. tinctorius was the most effective fungus and R. roseolus yielded poorer plant development. The highest application of urban refuse led to notably worse results and a significant decrease in seedling growth compared to controls. In the control plot (without refuse) S. collinitus was the most effective fungus in plant growth improvement. The smallest application of urban refuse had a positive effect on the assimilation of N, P, and K in seedlings inoculated with P. tinctorius and S. collinitus.