不同铁稳态水平下马铃薯幼苗碳水化合物分配特征和根形态建成

Distribution of carbohydrates and root morphogenesis of potato seedlings in vitro under Fe deficiency

【目的】为了探究铁(Fe)缺乏下马铃薯碳水化合物分配特征和根形态建成.【方法】以马铃薯栽培品种‘大西洋’试管苗为材料,在5个Fe水平(0、10、20、40、124μmol/L)的液体MS培养基上培养,17d后测定叶绿素、花青素、葡萄糖、果糖、蔗糖、淀粉等以及总根的长度、平均直径、表面积和体积,并用ICP-OES分析幼苗茎叶中各元素的含量.【结果】与对照(124μmol/L)相比,无Fe时,叶绿素显著降低(62%),花青素显著增加(130%);葡萄糖、果糖在茎、叶和根中均显著高于对照,蔗糖在茎、叶中显著降低13%,根中显著增加31%,茎、叶中淀粉显著增加13倍,根中显著降低67%;总根的长度、表面积和体积在Fe缺乏下均降低(20μmol/L Fe处理下均高于对照除外),平均直径在无Fe时显著增加26%;此外,Fe缺乏促进Mn、Zn含量增加.【结论】缺Fe影响碳水化合物代谢和根系建成,单糖在根中积累而多糖在茎、叶中积累,总根长度减少而平均直径增加,同时,Mn、Zn含量的增加有助于缓解幼苗铁缺乏.

【Objective】The physiological response mechanism and root growth pattern of potato seedling under iron（Fe）deficiency were investigated.【Method】Potato cultivars‘Atlantic＇seedlings were cultured on liquid MS medium at five levels（0,10,20,40,124μmol/L）of Fe treatments,after culturing 17 d,the following indexes were determined including the content of chlorophyll,anthocyanin,glucose,fructose,sucrose,starch,reducing sugar and soluble sugar,total root length,average root diameter,root surface area and root volume.The content of P,K,Ca,Mg,S,Fe,Mn,Zn,Cu,Mo,B,Al and Na in shoots was analyzed by ICP-OES.【Result】Compared with CK（with 124μmol/L Fe）,under the condition without Fe,the chlorophyll content,sucrose content in shoots and leaves,starch content in roots,total root length,root surface area,root volume of seedlings in vitro decreased significantly by 62%,13%,67%,70%,64% and 54%,respectively.With the decreasing of Fe deficiency,the content of glucose,fructose,sucrose in roots,and starchcontent in shoots,and average root diameter increased by 120%,130%,31%,13 times and 26%,respectively.Fe deficiency improved the increase of Mn and Zn content.【Conclusion】Fe deficiency influenced the carbohydrate metabolism and root morphogenesis so that monosaccharide accumulated in roots and polysaccharide accumulated in shoots and leaves,total root length decreased and average diameter increased.Meanwhile the increase of Mn and Zn of seedlings was also an adaptive response to Fe deficiency.