缺铁胁迫对3种梨砧木幼苗生理特性的影响

摘要

In order to select out theidealrootstock cultivars suitablefor highresistant cultivation of Kuerle Fragrant Pear toiron deifciency, taking Daduli (Pyrus betulifolia cv. Daduli), Duli (P. betulifoliaBunge cv. Duli )andMianli (P. xinjiangcv.Mianli )asmaterials, the effects ofiron deifciency stress on physiological characteristics of three cultivars of pearrootstock seedlingswere studied by solution culture. Theresultsindicated that theacidiifcation capacity of Duli seedlingswasgreater than that of DaduliandMianli, underiron deficiency stress. Underiron deficiency stress, Fe3+reductaseactivityinroot system of Duli seedlingswas 2.0 times of Daduliand 4.7 times ofMianli,respectively.Mianliwas thegreatest sensitive toiron deifciency stress,and demonstrated the highestlevel ofleaf chlorosis. Inall treatments, total iron contents of Daduliand Dulileaves (over 500mg·kg-1 DW)were higher than that ofMianli (under 450mg·kg-1 DW). Iron deifciency stressreduced totaliron contentinleaves of tree cultivarsat differentlevel. Iron deifcient stress exhibited the most signiifcantly effects onMianli,and totaliron contentinleaf declined 63mg·kg-1 DW. Theresults of comprehensive analysisindicated that theiron-deifciencyresistance sequence of the three pearrootstockswas Duli>Daduli>Mianli.%为了筛选出适用于库尔勒香梨高效抗缺铁栽培的理想砧木品种,以大杜梨、杜梨和棉梨为试验试材,通过溶液培养,比较了缺铁胁迫对这3种梨砧木幼苗生理特性的影响情况.结果表明:在缺铁胁迫处理下,杜梨幼苗的根际酸化能力大于大杜梨和棉梨.缺铁处理的杜梨幼苗根系的Fe3+的还原酶活性分别是相同处理下大杜梨和棉梨的2.0和4.7倍.棉梨对缺铁处理的反应最为敏感,其叶片在缺铁处理后的黄化程度最高;各处理下大杜梨和杜梨叶片的全铁含量(均在500 mg·kg-1·DW以上)均高于棉梨(450 mg·kg-1·DW以下).缺铁处理不同程度地降低了各品种叶片的总铁含量,其中缺铁处理对棉梨的效应最为明显,其下降幅度达63 mg·kg-1·DW,达到显著水平.综合分析各个指标测定值后认为,3种供试梨砧木品种中,在水培条件下其抗缺铁性的大小顺序为:杜梨>大杜梨>棉梨.