Evaluation On The Drought Resistance Of Perennials Introduced In Beijing

The water resources shortage make the promotion and application of drought resistant perennials became inevitable in Beijing landscape.Based on the investigation of perennials in Beijing landscape,the 4 drought resistant and widely used perennials as control,Iris lactea var.chinensis,Liriope spicata,Hemerocallis fulva ’Golden Doll’ and Dianthus plumarius,this study screened drought resistance evaluation index and evaluated the drought resistance of 20 perennials not popularized by gray correlation degree analysis,principal component analysis,membership function value and cluster analysis.Meanwhile,evaluating the field adaptability of sixteen perennials.The purpose was to select drought resistant perennials that could be used in Beijing and establish drought resistance evaluation system to provide references for related work in future.The conclusions were as follows:(1)There were 143 perennials in Beijing landscape.The frequency of L.spicata,I.tectorum,I.lactea var.chinensis,H.plantaginea and H.fulva ’Golden Doll’ was highest,and Sedum erythrostictum,H.fulva,Lythrum salicaria and D.plumarius was in the second.There were diverse landscape application forms,like ground-cover,flower bed,road edge,and so on.The 84 perennials(58.7%)just appeared in botanical garden or nurseries,no promotion.(2)The 4 control perennials,I.lactea var.chinensis,L.spicata,H.fulva and ’Golden Doll’were high drought resistant,but D.plumarius was moderate drought resistant.The rest of the 20 perennials,Potentilla tanacetifolia,I.lactea var.chinensis,L.spicata,H.fulva and ’Golden Doll’belong to the same level,for the high drought resistant,but the drought resistance of P.tanacetifolia was less than the other three,only slightly lower than the H.fulva and ’Golden Doll’.P.bifurca,Polygonum divaricatum,Chelidonium majus,Galium verum,I.sanguine,Silene jenisseensis and Ligularia fischeri were moderate drought resistant,in the same grade with D.Plumarius,and reduced according to the above order.Serratula centauroides,Scabiosa tschiliensis,Oxytropis coerulea,Thalictrum squarrosum,Aquilegia viridiflora f.atropurpurea,Scutellaria baicalensis,Heracleum hemsleyanum,Geum aleppicum,Pennisetum alopecuroides ’Little Bunny’,Sanguisorba officinalis,Saussurea amara and Agrimonia pilosa were weak drought resistant,and the drought resistance were lower than the 4 control perennials,and decreased according to the above order.(3)Using gray correlation degree analysis to screen out evaluation indicators,and the results indicated stoma density,Pn and root length had greatest influence on drought resistance,and plant height,drought resistance coefficient,crown width,WUEI,Tr,Gs,CE,Chl(a+b),Fv/F0,Pro,LRWC,POD,Fv/Fm and PR have greater influence on drought resistance,and WUEL have less influence on the drought resistance of perennials,and wilting coefficient,stoma length,stoma widtht,Rel and MDA have least influence on the drought resistance of perennials.For production,root length,plant height,crown width,drought resistance coefficient,wilting coefficient and WUEL were more meaningful because of simple determination method.(4)Drought resistance evaluation system of perennials including the evaluation indexes and evaluation method.The evaluation index should include morphology,growth,physiological and biochemical indexes,and used the grey correlation analysis to find out the major indexes.Evaluation method should use principal component analysis to solve overlapped information and determine the weight of each index,and then combined with the membership function value to obtain the comprehensive evaluation value of the test materials,drought resistance of sorting and clustering according to the comprehensive evaluation value.(5)Considering the drought resistance and adaptability in Beijing,high drought-resistant perennials,Iris lactea var.chinensis,Liriope spicata,Hemerocallis fulva ’Golden Doll’,Potentilla tanacetifolia,and moderate drought resistant perennials,P.bifurca,Polygonum divaricatum,Chelidonium majus,Galium verum,I.sanguinea,Dianthus plumarius and Silene jenisseensis could be applied in arid or water management not convenient locations.Serratula centauroides,Scabiosa tschiliensis,Oxytropis coerulea,Thalictrum squarrosum,Aquilegia viridiflora f.atropurpurea,Scutellaria baicalensis,Geum aleppicum,Pennisetum alopecuroides ’Little Bunny’,Sanguisorba officinalis,Saussurea amara and Agrimonia pilosa could be applied in a small amount of irrigation.Heracleum hemsleyanum and Ligularia fischeri were not suggested to apply in Beijing.