| Abbreviation | Definition |
|---|---|
| P | Pulsatilla |
| PAG | Plant Advisory Group |
| PAR | Photosynthetically Active Radiation |
| PBR | Poison Black Rose |
| PCNA | Pollination Constant Non-Astringent |
| PCOFGS | Phylum-Class-Order-Family-Genera-Species |
| PCR | Peanut Chlorotic Ringspot |
| PCRV | Peanut Chlorotic Ringspot Virus |
| PCTOC | Plant Cell, Tissue and Organ Culture |
| PEMV | Pea Enation Mosaic Virus |
| PEMV | Pepper Mottle Virus |
| PEMV-1 | Pea Enation Mosaic Virus - 1 |
| PEMV-2 | Pea Enation Mosaic Virus - 2 |
| PEN | Primary Endosperm Nucleus |
| PESTO | Photosynthesis Experiment System Testing and Operations |
| PEV | Position Effects Variegation |
| PFAF | Plants For A Future |
| PGR | Plant Gene Register |
| PGRI | Plant Gene Register Index |
| PGRI | Plant Genetic Resource Institute |