Effect of salinity on seed germination,ion content and photosynthesis of cotyledons in halophytes or xerophyte growing in Central Asia  

作　　者：Shirong Zhang Jie Song He Wang Gu Feng 

机构地区：[1]Department of Plant Nutrition,College of Resources and Environmental Sciences,China Agricultural University,Beijing 100094,China [2]Department of Biology,College of Life Science,Shandong Normal University,Jinan 250014,China

出　　处：《Journal of Plant Ecology》2010年第4期259-267,共9页植物生态学报（英文版）

摘　　要：Aims We investigated the impact of salinity on seed germination,chlorophyll content,chloroplast structure and photosynthesis of the green embryos in desiccated seeds of the xerophyte Haloxylon persicum,xero-halophyte Haloxylon ammodendron and euhalophyte Suaeda physophora.Methods Seeds of H.persicum,H.ammodendron and S.physophora were collected from natural environment in Fukang,Xinjiang province.Pretreatment with 700 mM NaCl was carried out to stimulate the natural‘seed priming’;we analyzed the joint effect of salinity and different species on germination physiology and cotyledonal structure and photosynthetic function changes during germination and recovery stage.Important Findings We found that seeds did not suffer ion toxicity for the two halophytes H.ammodendron and S.physophora,as evidenced by the high final germination after ungerminated seeds pretreated with 700 mM NaCl were transferred to distilled water,but the final germination of the xerophyte H.persicum was significantly lower than that of control.The Na+concentration in embryos increased under salinity for all species,while K+concentration decreased by salinity only for H.persicum and H.ammodendron,i.e.the concentration of K+in embryos of H.persicum and H.ammodendron decreased by 36%and 46%,respectively.For all species,whether dry intact seeds or cotyledons of dry seeds imbibed in deionized water and NaCl solution,had high chlorophyll content.Treatment with NaCl also caused chloroplast thylakoids to swell and chlorophyll content to decrease in seeds of H.persicum,but no significant change was observed in the more salt-tolerant species S.physophora and H.ammodendron.Fluorescence measurement showed that 700 mM NaCl decreased the Fv/Fm ratio of cotyledons in seeds for all species,especially for H.persicum and H.ammodendron.Photosynthetic oxygen releasing was detected from the seeds that were moistened with distilled water and 700 mM NaCl for 6 or 24 h and from the seeds that were initially moistened with 700 mM NaCl in darkness for 10 days,then tra

关 键 词：cotyledonal chloroplast Haloxylon ammodendron Haloxylon persicum SALINITY seed germination Suaeda physophora 

分 类 号：Q94[生物学—植物学]