Trichoderma crassum Bissett, Can. J. Bot.

Thokala, Prameeladevi, Narayanasamy, Prabhakaran, Kamil, Deeba & Choudhary, Shiv Pratap, 2021, Polyphasic taxonomy of Indian Trichoderma species, Phytotaxa 502 (1), pp. 1-27 : 11

6. Trichoderma crassum Bissett, Can. J. Bot. 69: 76– 79, 99. Figure 8

Section— Pachybasium

Description:

Colony: 4.0–5.0 cm growth was observed in 4 days on PDA medium. Slow growing, white floccose mycelium becoming bright yellow then turns to grey-green and then grey. Concentric rings of white, grey-green, grey and yellow are very conspicuous. Cushion like flat pustules spread throughout the plate. The reverse of the plate was yellowishorange.

Conidiophores: Conidiophores in minute pustules or effuse, branching irregularly, the apical part of the main conidiophores axis is straight or flexuous, sterile and unbranched. Long unbranched conidiophores with one or two phialides at the tip are sometimes present.

Phialides: Phialides mainly arising in crowded whorls of 2–5 on terminal and lateral branches, ampulliform to lagniform and subulate.

Conidia: Conidia broadly ellipsoidal to obovoid with the base slightly narrower, 3.0–5.0 × 3.0–3.5 µm, smooth and green.

Chlamydospores: Chlamydospores are globose, 4.0–6.0 µm diam.

Culture examined: ITCC 7293 (Soil, Assam).

Diagnostic features: White, grey-green, grey and yellow conspicuous concentric rings with a cushion like pustules and yellowish-orange at the reverse of the plate. Conidiophores apical part straight or flexuous, sterile and unbranched with crowded Phialides.

Ecology and habitats: Wood and soil.

Figures

FIGURE 8. Trichoderma crassum (A) Growth on PDA, (B) Pustules, (C) Reverse of the plate, (D) Pustule,(E,F,G,) Conidiophore branching, (H) Phialide disposition, (I) Spores, (J) Globose Chlamydospore.