Table 1. Avian Infectious Bronchitis virus strains tested by Melting curve analysis using RT-qPCR with SYBR Green I, respective access number in the Genbank, classification of genotype, Tm, fragment length and percentage of GC for HVR I and HVR II regions.
| S1 region | HVR I | HVR II | ||||||
|---|---|---|---|---|---|---|---|---|
| Virus strain | Accession numbera) | Genotypeb) | Tm (°C) | bp | %GC | Tm (°C) | bp | %GC |
| H120 | M21970 | Massachusetts | 81.77 ± 0.06c) | 228 | 41.23 | 77.77 ± 0.12c) | 191 | 32.46 |
| H52 | AF352315 | Massachusetts | 81.33 ± 0.06c) | 228 | 41.23 | 77.77 ± 0.12c) | 191 | 31.41 |
| Ma5 | AY561713 | Massachusetts | 81.30 ± 0.43c) | 228 | 41.23 | 77.80 ± 0.14c) | 191 | 32.98 |
| M41 | M21883 | Massachusetts | 81.77 ± 0.12c) | 228 | 42.54 | 76.16 ± 0.29d) | 191 | 30.37 |
| IBVSC01 | GQ169246 | Massachusetts | 81.17 ± 0.20c) | 228 | 40.79 | 77.70 ± 0.00c) | 191 | 32.98 |
| IBVPR03 | GQ169241 | Massachusetts | 81.33 ± 0.30c) | 228 | 41.23 | 77.55 ± 0.21c) | 191 | 32.46 |
| IBVPR07 | GQ169244 | Massachusetts | 81.33 ± 0.28c) | 228 | 40.79 | 77.63 ± 0.10c) | 191 | 32.98 |
| Connecticut | L18990 | Connecticut | 80.70 ± 0.10d) | 216 | 39.35 | 77.70 ± 0.05c) | 191 | 31.94 |
| IBVSC02 | GQ169247 | Connecticut | 80.60 ± 0.14d) | 216 | 39.35 | 77.70 ± 0.05c) | 191 | 31.94 |
| JMK | L14070 | JMK | 83.40 ± 0.10e) | 228 | 41.67 | 78.15 ± 0.07e) | 209 | 33.97 |
| SE 17 | AF239984 | SE 17 | 83.70 ± 0.10e) | 228 | 41.23 | 78.25 ± 0.21e) | 212 | 31.60 |
| IBVPR02 | GQ169240 | Brazilian Variant-B | 80.30 ± 0.34d) | 219 | 37.90 | 77.60 ± 0.14c) | 212 | 33.49 |
| IBVPR05 | GQ169242 | Brazilian Variant-C | 83.17 ± 0.12e) | 228 | 38.60 | 76.90 ± 0.14f) | 212 | 33.96 |
Significant differences between Tm’s values were detected by Scott-Knott test and are represented by different letters c–f), with P≤0.05. a) Genbank accession number for S1 gene sequence data where available. b) The genotype of each IBV strain had been examined previously by RFLP or nucleotide sequence of S1 gene [21, 26].