Physiological variation among Tricholoma matsutake isolates generated from basidiospores obtained from one basidioma

Abstract

Matsutake (Tricholoma matsutake) is a commercially valuable edible ectomycorrhizal mushroom. The physiological traits of T. matsutake have been previously assessed using mycelial isolates isolated from basidiomata; however, few studies have focused on basidiospores. Here, we report that sibling T. matsutake isolates generated from basidiospores on a single basidioma show distinct physiological variation. We first established 145 isolates of T. matsutake on modified Norkrans' C (MNC) agar medium and found that their radial growth varied significantly. The mycelial biomasses of nine isolates with different growth rates were reduced on low-carbon and low-nitrogen MNC media. However, the colony diam of one isolate was significantly elevated on low-carbon medium, and the colony diam of two isolates were significantly elevated on low-nitrogen medium. In co-cultures of two or three isolates, commensal and amensal interactions were observed. The physiological variation induced by low carbon and nitrogen levels and the mycelial interactions between sibling isolates imply mechanisms for the genetic and functional characteristics of mycelia of T. matsutake.

Successes and challenges in the sustainable cultivation of edible mycorrhizal fungi – furthering the dream

“…The present work on saffron milk cap cultivation indicates that it is possible to obtain high EMF yield from managed tree orchards. Establishing full-scale experimental EMF orchards, in which management treatments are tested statistically, is one priority for future research, as are an improved understanding of fruiting mechanisms of EMF (Le Tacon et al, 2016;Ogawa et al, 2019b), genomic and genetic studies (Martin & Bonito, 2012) aimed at elucidating fruiting mechanisms, and selecting or breeding for efficient symbionts (Saito et al, 2018;Yamada et al, 2019). The saffron milk cap yield data presented in this review can also serve as a reference for future full-scale replicated trials.…”

Sibling spore isolates of Tricholoma matsutake vary significantly in their ectomycorrhizal colonization abilities on pine hosts in vitro and form multiple intimate associations in single ectomycorrhizal roots

“…Nine sibling isolates (#31，#45，#52，#79，#84，#99，#111，#121，and #126) of T. matsutake were used in the experiments. They were selected from a line of 100 isolates established by spore isolation from a single basidioma collected in Takagi Village, Nagano, Japan, and showed physiological differences in their carbon and nitrogen nutrition (Yamada et al, 2019). These selected sibling isolates, which had been stored as slant cultures on modified Norkrans' C (MNC) agar medium (Yamada and Katsuya, 1995), were restored to mycelial growth on MNC agar plates.…”

“…The three isolates we tested (#52, #84, and #99) had two different restriction fragment length polymorphism (RFLP) patterns in the intergenic spacer (IGS) 1 region of the rRNA gene cluster (Yamada et al, 2019). We, therefore, first targeted this site to determine how mixed fungal inoculations develop ectomycorrhizal symbioses in the root system of a single host.…”

“…The shiro mycelium produces basidiomata annually for over a decade (Hamada, 1970;Ogawa, 1978;Narimatsu et al, 2015;Furukawa et al, 2016). The genetic structure of a single shiro may conceivably change over time because spore deposits from fruit bodies can theoretically result in di-mon mating or sibling di-di mating among germinated individuals within maternal shiro mycelium (Yamada et al, 2019). The observed genetic mosaic structure of a shiro requires experimental analysis to determine its ecophysiological significance.…”

“…Mycelial growth varied among 100 sibling isolates maintained on nutrient medium. Carbon and nitrogen nutrition and commensal interactions among isolates on nutrient agars also differed among selected isolates (Yamada et al, 2019). Thus, in the current study we first aimed to determine the extent to which sibling isolates differed in ectomycorrhizal colonization ratios and host responses.…”