Germination biology of Parthenocissus quinquefolia (L.) Planch. (Vitaceae).
We tested germination of seeds of Partheno-cissus quinquefolia (L.) Planch. (Vitaceae) in laboratory in response to different ecological factors: light intensity, temperature, humidity, acidity and salinity. Our results show that the most critical ecological factor is humidity. The highest rank of germination was 73% in condition of sufficient moisture, 37% in condition of excessive moisture and only 3% in condition with insufficient moisture. Among variants with different reaction of medium the most successful germination was at pH 7 (73%) and pH 9 (44%). Another significant factor for seedlings germination of P. quinquefolia is lighting, since at full-dark, dark and semi-dark conditions the level of germination was 0%, 2% and 24% respectively. The percentage of P. quinquefolia germination decreases with increasing salinity level. The most optimal germination regime was at +25°C. Further study of P. quinquefolia biology will allow to clarify the difference in naturalization level between this species and closely related P. vitacea as well as to estimate the possibility of transformation of the introduced species into invasive.