缺铁胁迫对3种梨砧木幼苗生理特性的影响

Effects of iron deficiency stress on physiological characteristics of three cultivars of pear rootstock seedlings

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6 3 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。

In order to select out the ideal rootstock cultivars suitable for high resistant cultivation of Kuerle Fragrant Pear to iron deficiency, taking Daduli （Pyrus betulifolia cv. Daduli）, Duli （P betulifolia Bunge cv. Duli ） and Mianli （P xinjiang cv. Mianli ） as materials, the effects of iron deficiency stress on physiological characteristics of three cultivars of pear rootstock seedlings were studied by solution culture. The results indicated that the acidification capacity of Duli seedlings was greater than that of Daduli and Mianli, under iron deficiency stress. Under iron deficiency stress, Fe^3＋ reductase activity in root system of Duli seedlings was 2.0 times of Daduli and 4.7 times of Mianli, respectively. Mianli was the greatest sensitive to iron deficiency stress, and demonstrated the highest level of leaf chlorosis. In all treatments, total iron contents of Daduli and Duli leaves （over 500 ·kg^-1 DW） were higher than that of Mianli （under 450 mg·kg^-1 DW）. Iron deficiency stress reduced total iron content in leaves of tree cultivars at different level. Iron deficient stress exhibited the most significantly effects on Mianli, and total iron content in leaf declined 63 mg·kg^-1 DW. The results of comprehensive analysis indicated that the iron-deficiency resistance sequence of the three pear rootstocks was Dull 〉 Daduli 〉 Mianli.