Seed Germination,seedling Growth And Population Regeneration Of Polygonum Aviculare L.

Polygonum aviculare L.is an annual herb,which is resistant to cold,tramping,drought and waterlogging,and has strong anti-pollution ability,longer green period,and is an excellent ground cover plant for lawn greening.In this study,the morphological characteristics of seeds were observed and germination experiments were carried out under five temperature varying conditions to explore the relationship between seed morphological difference and germination behavior.The germination phenology and seedling growth characteristics of heteromorphic seeds were adopted by outdoor imitation of natural conditions.In order to reflect dynamic characteristics of the population and the survival state,provide basic information for rational development and utilization of Polygonum aviculare,the dynamic life table of syngenetic population of Polygonum aviculare was compiled by observing the changes of individual survival of syngenetic population over time through the investigation and data statistics of sample plots.The main conclusions were as follows:(1)The same plant of Polygonum aviculare can produce tawny and dark-brown seeds,and seed germination has different behaviors.Tawny seeds have high germination rate and wide germination temperature range.The higher the temperature is,the faster the germination rate is,and the "risk" germination strategy is adopted.However,dark brown seeds have non-deep physiological dormancy characteristics,narrow germination temperature range,and have "cautious" germination strategy.The dormancy of dark brown seeds was effectively broken by scarification and cold stratification.Perianth had no effect on the germination of tawny seeds.(2)The germination phenology of the two heteromorphic seeds was not synchronous,and the cotyledon life varies.The tawny seeds germinated early and quickly,and the cotyledon re tention time was long,while the dark brown seeds germinated late and continuously,and the cotyledon retention time was short.The cotyledon retention time of large tawny seeds and small dark-brown seeds was 56 d and 39 d,respectively.The length and width of cotyledon of large tawny seeds were larger than that of small dark brown seeds.(3)The biomass and allocation patterns of the two heteromorphic seeds were different.The aboveground and underground biomass accumulation of the tawny seed seedlings was greater than that of the dark brown seed seedlings.The biomass of the tawny seeds was mainly transferred to the aboveground part of the seedlings,while that of the dark brown seeds was the opposite.(4)The population density of Polygonum aviculare basically increased before May,and there were three mortality peaks.The first peak mortality occurred in the Ⅱage group;The high temperature in July accelerated the evaporation of soil water,and the loss of water led to population self-thinning.The second mortality peak appeared in the Ⅶ age group.The third peak mortality is the XIII age group,which is normal.The population survival curve of Polygonum aviculare belonged to Deevey-Ⅲ,which was concave.The mortality rate of seedlings was high in the early growth stage and tended to be stable after September.