Effect of Different Light Quality and Photoperiod on Mycelium and Fruiting Body Growth of Tricholoma giganteum

TL;DR

This study shows how different light conditions affect the growth and nutritional quality of the mushroom Tricholoma giganteum during its mycelium and fruiting stages.

Contribution

The study introduces a two-stage lighting protocol using blue light for mycelium growth and green light for fruiting to optimize industrial cultivation of T. giganteum.

Findings

Blue light increased mycelial growth rate by 45% and polysaccharide content.

Green light improved fruiting yield and increased glutamate levels, a key umami compound.

A 4 h daily green light photoperiod maximized biological efficiency and nutritional content.

Abstract

Light is a crucial environmental regulator for Tricholoma giganteum (T. giganteum). This study investigated the effects of light quality and photoperiod on its growth, physiology, and nutritional composition. During the mycelial stage, blue light (BL) exposure for 5 d promoted the highest growth rate (0.74 mm d−1, 45% higher than dark control, p < 0.05). Red light (RL) enhanced antioxidant capacity, elevating superoxide dismutase (SOD) activity to 240.20 U·mL−1 (after 5 d) and DPPH radical-scavenging activity to 276.11% (after 3 d). Ultraviolet (UV) suppressed polyphenol oxidase (PPO) activity. BL also increased mycelial polysaccharide content (6.45 g·100 g−1). In the fruiting stage, green light (GL) improved agronomic traits and first-grade yield (3.75 kg), while also promoting the accumulation of glutamate (4.39 g·100 g−1), a key umami compound. Further photoperiod optimization revealed that 4 h of daily GL exposure shortened the fruiting cycle, achieved the highest biological efficiency (98.4%), and maximized both polysaccharide (38.17 g·100 g−1) and glutamate contents (5.70 g·100 g−1). These results recommend a two-stage lighting protocol: BL for mycelial growth and a 4 h daily GL for fruiting, providing a scientific basis for the industrial cultivation of T. giganteum.

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