DNA Extraction and ITS2 Amplification

The total DNA extractions were performed utilizing the Plant Genomic DNA Kit (Tiangen Biotech (Beijing) Co. Ltd., China) according to the manufacturer’s instructions. The DNA concentration and quality were assessed by Nanodrop 2000C spectrophotometry (Thermo Fisher Scientific Inc., China) and 0.8% (w/v) agarose gel electrophoresis at 120 V for 40 min (Bio Rad Laboratories Inc., USA), respectively. According to the procedure provided by Chen et al.^{31 (link)}, PCR amplification of ITS2 was performed in 50 μL reaction mixtures using 2 × Taq MasterMix (AidLab Biotechnologies Co. Ltd., China), with the annealing temperature increased to 58 °C for 40 cycles. The PCR products were purified by Universal DNA Purification Kit (Tiangen Biotech (Beijing) Co. Ltd., China) and were quantified and assessed by Nanodrop 2000C spectrophotometry and 2% (w/v) agarose gel electrophoresis at 120 V for 30 min. Resulting DNA products were used in the following assay.