Fig 1.
Schema representing the bioassay of the in vitro association between Psidium cattleianum (Red Araza) and ectomycorrhizal fungi D17 and UFSC-Sc133.
(A) Methodology for the symbiosis bioassay. (B) Test tubes containing vermiculite and Red Araza seedlings, where: Ct, control (no fungi added); Sc, treated with mycelium from the UFSC-Sc133 (Scleroderma citrinum) isolate; and Pi, treated with mycelium from the D17 (Pisolithus microcarpus) isolate. *Modified Melin-Norkrans Medium [27] containing 10 g of glucose, 5 g of sucrose, and 200% of the micronutrients from an MS0 medium [28]. Squares were dimensioned at 1 cm by 1 cm.
Table 1.
Ectomycorrhizal colonization percentage for Red Araza (Psidium cattleianum) plants after 110 days.
Fig 2.
General aspects (A, B and C) and details (D, E and F) of the root system from the Red Araza plants inoculated with ectomycorrhizal fungi (fEcM), after 110 days of in vitro cultivation. (A) and (D) Control plants, no fEcM inoculation. (B) and (E) Plants inoculated with Pisolithus microcarpus (D17). (C) and (F) Plants inoculated with Scleroderma citrinum (UFSC-Sc133). (p, radicular hairs; m, fungal mantle; c, mycelial cords). Squares were dimensioned at 1 cm by 1 cm.
Fig 3.
Root system details of the Red Araza non-inoculated plants (A) and of the Red Araza inoculated in vitro with the D17 (Pisolithus microcarpus) ectomycorrhizal isolate (B, C, D, E, F and G). (A) Roots non-colonized by radicular hairs (p). (B) detail showing roots partially (ri) and completely (re)covered by mycelium. (C) Sample showing a colonized root's pinnate monopodial morphotype (re). (D) Secondary root covered by yellowish mycelium, with mantle (ma) formation on the apex. (E) and (F) Secondary roots covered by the mantle, with yellowish rhizomorphs (rz). (G) Details of the dichotomized secondary roots. Bars represent a 1 mm scale.
Fig 4.
Root cross-sections of the Red Araza non-inoculated plants (A, D) and of the Red Araza inoculated in vitro with the D17 (B, E) and UFSC-Sc133 (C, F) isolates. D17 –Pisolithus microcarpus; UFSC-Sc133 –Scleroderma citrinum. Note the presence of radicular hairs (p) in A and D, and the formation of a mantle (ma) that partially (C and F) or completely (B and E) covers the root. E and F show the presence of a Hartig net (rH). (ep, epidermis; vc, conducting vessels; en, endoderm).
Fig 5.
Scaning electron micrograph of Red Araza (Psidium cattleianum) roots.
(A) Control root, arrow shows root hairs. (B) and (C) Ectomycorrhizae formed by symbiotic relationship with the D17 isolate (Pisolithus microcarpus), arrow shows thick fungal mantle. Bars on A and B represent a 100 μm scale and, on C, a 200 μm scale.
Table 2.
Number of leaves, fresh and dry shoot masses, largest root length and relative growth rate (RGR) of Red Araza plants (Psidium cattleianum) in different phases of ectomycorrhizal fungi inoculation and without inoculation.