Abstract
Polygonum perfoliatum L. is an aggressive vine, currently invading the Black Sea region, Turkey. However, information about the seed germination biology of this species is scanty. The objective of the current study was to determine the seed germination biology of three naturalized populations of this species. Chemical scarification with 98% sulfuric acid for 30 min followed by cold-wet stratification at 4 degrees C for 4 weeks effectively released seed dormancy in tested populations. Seeds of all populations required a 12 h photoperiod for the highest germination, while germination under continuous dark and light remained similar. The seeds were able to germinate under a wide range of constant (5-40 degrees C) and alternating temperatures, pH (3-11), osmotic potential (0 to -1.4 MPa) and salinity (0-500 mM NaCl). However, the peak germination was observed under 20 degrees C constant and 20/15 degrees C alternating day/night temperature, and pH 6.8. Seeds of all populations were able to withstand 200 mM salinity and -0.6 MPa osmotic potential. Increasing seed burial depth initially stimulated seedling emergence and then a sharp decline was observed for the seeds buried below >2 cm depth. More than 90% of the seeds were unable to emerge when buried >6 cm depth. Polygonum perfoliatum has a large potential for range expansion; therefore, immediate management of the naturalized populations is warranted. This weed species in agricultural fields can be managed by burying the seeds in deeper soil layers (6 cm), while post-emergence management strategies need to be developed for roadside populations.