Survey of major capsid genes (g23) of T4-type bacteriophages in rice fields in Northeast China

We surveyed the capsid genes (g23) of T4-type bacteriophages in DNA extracted from fifteen rice field soils in Northeast China using primers MZIA1bis and MZIA6. Denaturing gradient gel electrophoresis (DGGE) was performed to separate PCR-amplified g23 products. In total, 53 DGGE bands were identified as g23 clones, nine of which belonged to a novel, Northeast China-specific group. In addition, four and six clones formed two novel groups with previously ungrouped clones obtained from Japanese rice fields. The majority of the remaining clones fell into Paddy Groups I and V, none of the clones belonged to Paddy Groups II, III, IV, and VI, indicating that phylogenetic distribution of g23 genes in rice fields in Northeast China was different from that in Japanese rice fields.