Basidiospores attach to the seed of Shorea leprosula in lowland tropical dipterocarp forest and form functional ectomycorrhiza on seed germination

Abstract

This research aimed to study the ectomycorrhiza formed by basidiospores attached to the outer surface of Shorea leprosula (Dipterocarpaceae) seed collected from a lowland tropical dipterocarp forest. Two groups of seeds were collected: control seeds collected from plastic net hanging 2 m above the ground and forest floor seeds collected on the forest floor. Before planting, 15 seeds from each group were observed for basidiospores attached to the seed. Ten of the 3-week-old S. leprosula seedlings of each group were individually grown in 1.5 kg of sterile zeolite for 8 months in a greenhouse. Pots were fertilized with MMN solution containing half the strength of phosphate. Fungal identity, ectomycorrhizal root tip colonization and anatomy, plant growth, and phosphate uptake were measured. The control seeds did not have basidiospores attached, whereas the forest floor seeds had 2 × 10 basidiospores of Tomentella. Bioassay test results indicate that the seedlings from the control seeds did not form ectomycorrhiza, whereas those seedlings from the forest floor seeds formed 3 morphotypes of ectomycorrhizae. Based on ITS1, 5.8S, and ITS2 rDNA region analyses, the 3 morphotypes belonged to Tomentella sp. HBT2, Tomentella sp. HBT4, and Scleroderma sp. HBS3. Root colonization percentage was above 70% for all three morphotypes. Root colonization in general increased plant growth and phosphate uptake. This is the first report of Tomentella basidiospores attached on the seed surface as a functional inoculum and of Tomentella ectomycorrhiza from dipterocarps lowland tropical forest.

Ectomycorrhizal Fungi on South Kalimantan Serpentine Soil

“…The symbiosis of ectomycorrhizal fungi is specific (Brundrett et al, 1996). The genus of plant that capable of developing the association with ectomycorrhizal fungi was Acacia (Bellgard, 1991), Dipterocarps (Brundrett, 2009;Karmilasanti & Maharani 2016;Ulfa et al, 2018), Pinus (Koide & Wu, 2003;Darwo & Sugiarti, 2008;Dewi et al, 2016) and Shorea (Alamsjah & Husin, 2010;Ramadhani et al, 2018). Karmilasanti & Maharani (2016) also reported the host besides Dipterocarp, such as Canarium, Cleodepas, Gluta, Krema, Madhuka, Ptarospermum, and Syzygium.…”

Should I stay or should I go? Mycorrhizal plants are more likely to invest in long‐distance seed dispersal than non‐mycorrhizal plants

“…; Ramadhani et al . ), thus, most plants acquire mycorrhizal fungi from the environment after germination (Smith & Read ). Therefore, the need to disperse seeds to suitable sites where they can encounter compatible mycorrhizal fungi could favour the co‐evolution of traits to promote a non‐random dispersal of seeds and fungi spores.…”

A pantropically introduced tree is followed by specific ectomycorrhizal symbionts due to pseudo-vertical transmission

“…Indeed, spores were recently found on dry seeds of a Southern Asian Dipterocarpaceae tree, Shorea leprosula, inoculating Thelephoraceae and, interestingly, Scleroderma spp. on seedlings [54]. The seagrape-Scleroderma pseudo-vertical transmission may explain (i) the abundance of Scleroderma in all seagrape ECM communities [30], and (ii) why other taxa mycorrhizal associated with seagrape in ROs scarcely ever colonize seagrape in RIs.…”

“…found in RIs, we cannot exclude that they pre-existed in these regions. However, Thelephora have a potential to be dispersed on ECM hosts' seeds [54]. Thelephora #2, very abundant on Malaysian seagrapes, is known from Guadeloupe [32], may thus be another co-introduction of a specific symbiont.…”