Study On The Plant Resources Of Potentilla And Their Adaptation In Beijing And Surrounding Areas

With rich morphological diversity,Potentilla are widely distributed.And because of the high ornamental value and good ecological adaptability,Potentilla play an irreplaceable role in constructing the urban ecological landscape,which makes development prospects.However,the lacking research on the growth and development law and adaptation of Potentilla limits its application in landscaping.Given this,a study dedicate on these two aspect was conducted.Through a comprehensive investigation of Potentilla in Beijing and surrounding areas,its natural distribution characteristics,growth and development law were summarized.Beside,the paper did research on the drought and shade adaptation of Potentilla.simulatrix,P.reptans and P.reptans.var.sericophylla.Conclusions were drawn as follows.1)20 species(varieties)involved in 5 sect and 11 ser in Flora of China were found in Beijing and its surrounding areas,accounting for about 1/4 of the total Potentilla resources in the country.Then,taxa key was developed based on the morphological characteristics.Four types were defined according to the elevation distribution characteristics of Potentilla.Similarly,they can also be classified into four types based on their optimal growth environment,namely rock-crag type,meadow and water-edge type,forest-edge type,and hillside type.2)In this study,12 cultivars(varieties)of Potentilla were successfully introduced and observed their phenophase.The results showed that majority Potentilla sprouted in March,leafing after a week or two,blossoming and bearing fruit from April to May,withered after November,and the growth period ranged from 220 days to 280 days.According to the morphological characteristics of Potentilla species,12 species of Potentilla plants were divided into four types:reptans,high,medium and short Potentilla.According to their propagation mode,they were divided into the propagation style of stolons,sprouting,seed,and underground rhizome.3)The drought adaptability research was conducted for Potentilla.simulatrix,P.reptans,P.reptans.var.sericophylla.And during the drought stress period,the leaf relative water content,specific leaf area,chlorophyll content,Fv/Fm,Yield,qP,NPQ,Soluble sugar content,protein,proline and other physiological,biochemical and photosynthetic systems respond positively to mitigate the damage caused by drought,but the long-term drought will still cause serious inhibition of its physiological mechanism,and ultimately manifested in the morphological indicators.In a comprehensive judgment,the drought tolerance of the three plants was equal to that Potentilla.simulatrix>Potentilla.reptans>P.reptans.var.sericophylla.4)The shading adaptability tests of P.simulatrix,P.reptans and P.reptans.var.sericophylla were conducted.The results showed that all three species had a wide range of light adaptation and had a strong ability to shading.Under shading treatment,the plant morphology of three potentillas were changed,and the relative response of the leaf water content,specific leaf area,photosynthetic system,osmotic adjustment system,and membrane system together to adapt to low light conditions.Based on landscape application standard,the ornamental value of three potentilla under moderate shade rate are best.