EFFECTS OF DISSOLVED OXYGEN, pH AND OTHER PHYSICO2CHEMICAL FACTORS ON THE SEED GERMINATION OF POTAMOGETON PECTINATUS

Restoration of aquatic ecosystemin eutrophic lakes relies on restoration of submerged vegetation. Vegetative and sexu2 al reproduction under eutrophic conditions may play important role in the establishment of submerged plant community. Pota2 mogeton pectinatus were widely distributed and abundant in Chinese lakes. In this study the effects of anoxia and other ecological factors, e.g. nutrients, light intensity, temperature, pH, pre-cooling treatment, on the germination of seeds of Potamogeton pectinatus were investigated.The effects of dissolved oxygen, pH, light, pre2cooling treatment, temperature, nutrients, and hormones on the germina-tion of seed of Potamogeon pectinatus were investigated. In comparison to the high dissolved oxygen condition, the germination rate under anoxia condition was enhanced, however, the sprouts loose capacity of pigment synthesis and cease development. Light intensity(0-2000lx)and pH(6-8) had no effect on the germination. Pre2cooling treatment of seeds under 4 ℃ for 30d and 150 d speeded up the germination and promoted germinatian rate. Incubation under higher temperature germinated earlier in the range of 15-27 ℃. The germination rates under 15, 20 and 27 ℃ were 90 %,90 % and 5617 % respectively. Nutrients had no effect on the germination. Auxin NAA(0.1-5.0 mg/L),cytokinin 6-BA(0.1-5.0mg/L)or gibberellin G A3(0.1-5.0mg/L) did not enhanced the germination rate.