Comparative Study On Phenotype Plasticity Of Four Saussurea Species In East Of Qinghai-Tibet Plateau

Phenotypic plasticity was defined as the property of a genotype produce differe nt phenotypes when exposed to different environments.Recently,intensive study has s hown that plants are plastic for a remarkable array of ecologically important traits,r anging from diverse aspects of morphology and physiology to life historical traits.Pl asticity differences between species have important implications in terms of ecologic al and evolutional consequence.The phenotypic plasticity response to light and nutrie nt were compared in this paper with four species in East of Qinghai-Tibet Plateau: Saussurea macrota Franch,Saussurea japonica (Thumb.) DC.,Saussurea hieracioi des Hook.f.,Saussurea kansuensis Hand.-Mazz.The seedling emergence,seedling su vival,growth and morphology plasticity of four Saussurea species were studied.We precent the comparative study to probe into phenotypic plasticity patterns of these f our Saussurea species in response to different light and nutrient,aiming to find out the relationship between the phenotypic plasticity and field distribution.The results a re as follow:1. The Saussurea species differed significantly in their emergence and mortality res ponse to light. S.macrota and S.japonica had higher emergence and lower mortal ity, S.hieracioides were higher emergence and higher mortality, S.kansuensis wer e lower emergence and higher mortality.2. The Saussurea species differed significantly in their patterns of growth and morphology response to light and nutrient spatial variability.The widespread species li ke S.macrota and S.japonica had higher phenotypic plasticity than that of the sp arsity like S.hieracioides and S.kansuensis3. The Saussurea species had higher SLA in the HL treatment compared to the HHtreatment, S.macrota and S.japonica seedlings had significantly higher plasticitycompared to S.hieracioides and S.kansuensis.The conclusion that we can draw from this study is that S.macrota and S.japoni ca out performed S.hieracioides and S.kansuensis under most environmental tested a nd showed a wider regeneration niche.