Mechanisms Of Environment Alresponse To Syringa And Viburnum.L Plantex-situ Conservation

In the process of plant ex situ conservation,the natural environment climate such as temperature,light and precipitation is undoubtedly the main factor affecting plant growth and breeding in the introduction area,and the species formed in the long-term adaptive evolution of provenance,which the response mechanism of growth and flowering is also common and different in the environmental changes in the introduction.The geographical distribution of the Viburnum.L and Syringa.L is widely distributed,and the growth,flowering plasticity and environmental response between different species are different.Under the background of global climate change,abnormal meteorological events occur frequently,so the growth,health status and flowering time of ex-situ conservation woody plants are greatly affected.After the abnormal cold and humid weather in the spring of 2010,there was an unusual warm and arid weather event in the spring of 2016.We focused on quantitative effect of Viburnum and Syringa genus' plants growth,flowering characteristics and phenological characteristics of seedlings,and these plants grow under the acclimation environment where have interaction of changing climate in spring as well as high temperature under strong light,through the monitor of field acclimation of Viburnum genus' plants on flowering phenology response to spring abnormal weather events,and Syringa genus' plants were grown in the control of temperature and light.Finally,we reveal the similarities and differences between the characteristics of acclimation adapt according to the background of three dimension zonality.The perennial flowering phenology of Viburnum L.during two meteorological events and other normal years from 2009 to 2016 were observed,the results showed advancement of florescence in abnormal warm dry weather in spring,and their florescence was not shortened.As for Viburnum macrocephalum and V.opulus of the vertical distribution with small altitude span,their initial flowering period,the accumulated temperature before the flowering period and the florescence varied greatly annually.While for V.prunifolium,V.melanocarpum,V.carlesii located with the larger altitude,their initial flowering period,the accumulated temperature before the flowering period and the florescence showed small plasticity,and flowering period is also relatively fixed.In warm and droughty spring,the assimilation products of branches increased with the increase of the diameter of branches,and leaf growth rate became faster,the leaf area became bigger but thinner,and the distribution of assimilated products of the leaves far from fruits increased significantly,which was harmful to the supply of fruit products.After dispose of temperature and light gradient processing of Syringa L.seedlings for 4 weeks,it was found that the decrease of photosynthetic rate and stomatal conductance of the Syringa oblata with large span of the three-way zonal distribution(longitude,latitude and altitude)was lower,and the effects of high temperature were alleviated by leaf transpiration and heat dissipation at the level of high temperature of 37 ?.At the same time photosystem II(PSII)also was damaged unreversely by high temperature.The S.oblata has a small physiological plasticity at the ambient temperature with the gradient change of light.And the photosynthetic rate and stomatal conductance of the narrow-area species S.Reflexa were decreased greatly,and the transpiration and dissipation of the leaves could not prevent the high temperature stress,while the structure of PSII was damaged,while it showed great physiological plasticity during the changes of environment,but the photosynthetic physiological response regulation did not form high temperature adaptation to lead high temperature stress.Another result is that the light itself does not affect the gas exchange and the distribution of biomass of whole plants,but it works for plant gas exchange under the interaction of light and temperature,and influence extent of interaction is different due to different species.The effect of the treatment on the morphological aspects during the four-week trial period has not yet been observed,but the narrow-area species S.Reflexa has larger and lower density stomas than the wide-area species Syringa oblata,it is also an important limited factor of heat exchange capacity of narrow leaf.The study of the phenotypes of the flowering plants in the abnormal meteorological events has made us to track the environmental plasticity of the characteristics of species breeding more precisely.It provides basic information for systematical cognition of climate change response and phenological large-scale data analysis of exclusive plants.The response mechanism of wide-area and narrow-area species to temperature and light changes in the introduction was determined by temperature-light-controlled plant growth test,it can determine the effect contribution of each treatment on seedling growth,customize the targeted introduction and domestication strategy,and improve the efficiency of relocation of narrow-area species.