Table 2. Average of DNA concentration(ng/μl), purity(A260/A280) and PCR success rate by group of samples.
| Annual ring group | Number of samples | DNA conc.(ng/μl) | DNA Purity (A260/A280) | PCR success rate(%) |
| trnM-trnV | rpoC1 | rbcL |
| 1~5 | 3 | 2.48 (±0.97) | 1.21 (±0.24) | 100 | 100 | 100 |
| 6~10 | 3 | 1.97 (±0.61) | 1.28 (±0.01) | 100 | 100 | 100 |
| 11~15 | 3 | 4.22 (±0.77) | 1.26 (±0.04) | 100 | 100 | 100 |
| 16~20 | 3 | 2.37 (±0.06) | 1.44 (±0.05) | 100 | 100 | 100 |
| 21~30 | 3 | 0.97 (±0.16) | 1.05 (±0.08) | 100 | 100 | 100 |
| 30~35 | 3 | 1.67 (±0.91) | 1.02 (±0.27) | 100 | 100 | 33.33 |
| 36~40 | 3 | 1.07 (±0.50) | 1.16 (±0.22) | 100 | 100 | 0 |
| 41~45 | 3 | 0.78 (±0.05) | 1.04 (±0.05) | 100 | 100 | 0 |