Table 1. PCR amplification of the partial IGS2 region of Tricholoma matsutake using the TmSP-I-2F/TmSP-I-2R primer pair.
| Sample group of pine plants | Name of pine plant | Sample name3 | N | Number of replicated samples detected T. matsutake | ||
| −BSA | +BSA | Total | ||||
| Outplanted mycorrhizal seedling1 | Nagano 106 (AT-0740) | EMRT | 23 | 0/23 | 1/23 | 1 |
| ERM in soil | 2 | 0/2 | 0/2 | 0 | ||
| ERM in soil | 5 | 0/5 | 2/5 | 2 | ||
| EMRT (not T. matsutake) | 1 | 0/1 | 0/1 | 0 | ||
| Nagano 139 (SI-001) | EMRT | 26 | 1/26 | 9/25 | 10 | |
| EMRT (not T. matsutake) | 1 | 0/1 | 0/1 | 0 | ||
| Ibaraki 1 (AT-638) | EMRT | 3 | 0/3 | 0/3 | 0 | |
| ERM in soil* | 9 | 1/9 | 0/8 | 1 | ||
| ERM in soil | 1 | 1/1 | ND | 1 | ||
| EMRT (not T. matsutake) | 1 | 0/1 | 0/1 | 0 | ||
| Ibaraki 4 (AT-638) | EMRT | 5 | 0/5 | 0/5 | 0 | |
| ERM in soil | 3 | 0/3 | 0/3 | 0 | ||
| EMRT (not T. matsutake) | 1 | 0/1 | 0/1 | 0 | ||
| Ibaraki 9 (AT-638) | EM root tips | 4 | 0/4 | 0/4 | 0 | |
| Shindai-spore+ (# 84) | EMRT | 3 | 1/3 | 0/2 | 1 | |
| EMRT (not T. matsutake) | 1 | 0/1 | 0/1 | 0 | ||
| Shindai-spore− (# 84) | EMRT | 2 | 0/2 | 1/2 | 1 | |
| EMRT (not T. matsutake) | 2 | 0/2 | 0/2 | 0 | ||
| Outplanted non-mycorrhizal air-layered plant1 | Nara-blue 1 | EMRT | 3 | 1/3 | 0/2 | 1 |
| Nara-blue 2 | EMRT** | 3 | 3/3 | ND | 3 | |
| EMRT (not T. matsutake) | 1 | 0/1 | 0/1 | 0 | ||
| EMRT on oak tree | 1 | 0/1 | 0/1 | 0 | ||
| Nara-blue-rest | EMRT | 10 | 0/10 | 0/10 | 0 | |
| EMRT (not T. matsutake) | 2 | 0/2 | 0/2 | 0 | ||
| Growing wild seedling2 | No label | EMRT | 8 | 1/8 | 0/7 | 1 |
| Total | 121 | 9 | 13 | 22 | ||
1 These mycorrhizal seedlings and air-layered non-mycorrhizal plants were planted in May 2016 and Oct 2016, respectively, at a point 10-15 cm from the front zone of the shiro area of naturally colonized T. matsutake in the forest site.
2 The pine seedlings were 2-y-old when collected in Jun 2016, and grew naturally in the front zone of the shiro area of naturally colonized T. matsutake in the forest site.
3 EMRT: ectomycorrhizal root tips on the transplanted plant; ERM: extraradical mycelium around the root system of the transplanted plant.
* Adult pine ectomycorrhizal root tips were included in each sample.
** A fruiting body of T. matsutake occurred during sampling (Supplementary Fig. S2), and the shiro mycelium was associated with the ectomycorrhizal root tip samples.