The use of chemical pesticides to protect agricultural products is a global concern because of their adverse effects on the environment and public health. To avoid the dangers of synthetic herbicides, research has turned to natural alternatives. This study was conducted to evaluate the allelopathic effect of essential oil (EO) extracted from Origanum syriacum, Origanum onites, and Origanum majorana. In addition, the chemical composition of the essential oil was elucidated by gas chromatography and mass spectrometry (GC–MS) analysis. A total of 11 different components of O.syriacum were identified, and the main components were carvacrol (88.49), p-Cymene (5.71), γ-Terpinene (1.63), β-Caryoplhyllene (1.48), and Terpinen-4-ol (0.65), respectively. For O. onites, 10 different compounds were identified, and the main components were carvacrol (58.65), Thymol (30.97), Linalool (4.17), p-Cymene (1.94), and β-Caryoplhyllene (0.98), respectively. Finally, for O. majorana, 14 different compounds were identified, and the main components were carvacrol (40.57), α-Terpineol (29.28), p-Cymene (9.02), γ-Terpinene (5.80), and carvacrol methyl ether (3.46). Finally, 14 compounds from the Origanum majorana species were identified, with carvacrol (40.57), -Terpineol (29.28), p-Cymene (9.02), and -Terpinene (5.80) as the parent compound (3.46). Oxygenated monoterpenes were the highest in all species’ EO content. EOs and plant extracts were tested at 5, 10, and 20 L/Petri concentrations against seed germination and seedling growth in four weed species (Thlaspi arvense, Amaranthus retroflexus, Rumex cripus, and Lactuca serriola). The concentrations of essential oil were set as 5, 10, and 20 µL/Petri dishes for seed germination. In the greenhouse experiment, the final concentration of solutions was set as 20 µL and the solutions were directly sprayed on the surface of the weeds, and the mortality rates were noted after 24 and 48 h of application. It was observed that increasing the application decreased seed germination. The phytotoxic effects on the seedling germination in the greenhouse were observed, resulting in 48.76–94% mortality rates. Consequently, the essential oil from Origanum species could be considered as an alternative bio-herbicide to tested weeds.

In this study, fungal samples collected in Mugla province were identified as Hortiboletus bubalinus (Oolbekk.&Duin)L. Albert & Dima and recorded for the first time for the Turkish mycobiota. Short description, photographs, locality, collection date and ecological features of this newly reported species was also provided.

The current study presents a Turkish Truffle Checklist based on literature and a newly discovered species. Within the two divisions, the list includes 104 species belonging to 35 genera and 20 families, as well as their range and Turkish names. Tuber oligospermum was one of them, and it was recorded for the first time in Turkey. A brief description of newly reported species was provided, along with images of their macro and micro-morphology.

Tuber magnatum Picco, the Italian white truffle mushroom recorded for the first time in Türkiye, is a rare and economically valuable mushroom. Samples were collected from Sakarya province during field studies in 2024. The samples were identified as T. magnatum according to their macro- and microscopic features. To make molecular confirmation of the species, the samples' ITS1 and ITS4 gene regions were analysed and registered in Genbank with the number PP239641. The sample showed 100% compatibility with other T. magnatum accessions in Genbank. The distributions of Tuber species in Türkiye were given, and their taxonomic features were compared.

Gymnopus aquosus (Bull.) Antonin & Noordel and Inocybe subporospora Kuyper were recorded for the first time in Türkiye, among the fungal specimens collected during field studies in Kütahya. The specimens were identified based on morphological, microscopic features and analysis of ITS gene sequences. The habitats and characteristic features of the species are briefly explained and relevant photographs are presented. GenBank accession numbers were assigned to the samples in this study and phylogenetic trees were constructed to compare them with similar taxa. Gymnopus aquosus is mainly characterized by and distinguishes it from related species; have an almost to the center translucently striate, pileus center pale yellow to ochre, pallescent to almost white towards to margin and a distinctly bulbous base with pinkish-chromic rhizomorphs. Inocybe subporospora; have spores with an indistinct germ-pore, red-brown stipe and dark grayish brown pileus with rimulose margin is a very characteristic species that can be distinguished from its close species with its features.

Aim of study: We aimed to i) evaluate the effects of mulching on Tuber melanosporum mycelium biomass and seedling growth (i.e. root collar diameter and seedling height) and ii) unravel the relationship between growth in root collar diameter and mycelium abundance, in a T. melanosporum plantation.Area of study: The experimental plantation is located in the Pre-Pyrenees mountains in Catalonia, Spain.Material and methods: The experimental plantation was established in 2010 using one-year-old T. melanosporum inoculated Quercus ilex seedlings. Double-layered mulch materials were placed around the seedlings. The mulch materials were removed from randomly selected seedlings in 2015 and 2018. Soil samples were collected in 2018 at 40 and 80 cm distances from seedlings that had mulching during five and eight years, and T. melanosporum mycelium biomass was estimated by quantitative Polymerase Chain Reaction (qPCR). Seedling root collar diameter and height were measured simultaneously when mulch materials were removed.Main results: Mulch removal time did not have significant effects on T. melanosporum mycelium biomass or seedling growth. However, mycelium biomass at 40 cm distance tended to be higher on seedlings after eight-year mulching with 0.9 mg/g soil whereas mycelium biomass was 0.4 mg/g soil after five-year mulching. A positive relationship between mycelium biomass and seedling root collar diameter was also found.Research highlights: Mulching seems to have a positive effect on truffle mycelium biomass, with nearly two times higher quantity of mycelium after eight-years compared with five-years mulching usage. Seedling root collar diameter is a good indicator of mycelium expansion in the plantation.Keywords: Black truffle; Quercus ilex; mulching; tree growth; truffle cultivation.