基于质外体pH和铁素分析的‘库尔勒香梨’黄化症诊断研究  

Study on diagnosis of leaf chlorosis disease of‘Kuerle fragrant pear'(Pyrus bretschneideri Rehd. ) by pH and iron concentration in apoplast sap

作　　者：赵越[1] 吴玉霞[1] 何天明[1] 

机构地区：[1]新疆农业大学林学与园艺学院,乌鲁木齐830052

出　　处：《果树学报》2016年第2期210-216,共7页Journal of Fruit Science

基　　金：国家自然科学基金(31160382);新疆维吾尔自治区重点学科果树学建设项目(201007)

摘　　要：【目的】因缺铁而引起的叶片失绿黄化是新疆塔里木盆地钙质土壤栽培的‘库尔勒香梨’一种严重的生理性病害。通过分析‘库尔勒香梨’叶片黄化与木质部汁液pH值以及铁素含量的相关关系，探索基于质外体pH和铁素分析进行‘库尔勒香梨’黄化症早期诊断的可行性。【方法】通过微电极测定了‘库尔勒香梨’木质部质外体汁液的pH值，并分析了不同部位木质部汁液和叶片中总铁和有效铁含量。【结果】‘库尔勒香梨’各器官木质部质外体汁液的pH值在生长季大多保持在5．0—6．0，属正常生理范围。正常树的木质部汁液pH值略高于黄化树（5．6％），但与铁失活关联度不大。同一采样部位总铁的浓度在黄化树和正常树之间无显著差异。整个年生长季，正常树各器官的有效铁含量均极显著高于黄化树。【结论】叶片质外体pH值为叶面铁肥配制和黄化症诊断提供了重要参数，而‘库尔勒香梨’其他器官质外体pH值对黄化症诊断无直接参考价值。在‘库尔勒香梨’黄化病营养诊断时，总铁含量不能准确表征‘库尔勒香梨’植株叶片的铁营养水平，采用叶片有效铁含量作为量度指标更为可靠。[Objective] In oasis of Talim Basin of southern Xinjiang, China, the soil is highly calcerous and alkaline, with pH above 8.2. Under such high pH, soluble iron in the soil might be fixed and active iron might decrease greatly.＇ Kuerle fragrant pear＇ （Pyrus bretschneideri Rehd.） is a fruit tree species great- ly affected by iron deficient chlorosis in the area. The objective of this work was to study the relationship between leaf chlorosis and pH and leaf iron concentration in xylem sap, with the final aim to explore the possibility of early diagnosis of iron chlorosis in＇ Kuerle fragrant peat＇by pH and iron concentration in xy- lem sap. [Methods]The plants were six-year-old ＇Kuerle fragran （Pyrus betulifolia Bunge）. At the different stages of growing season, t pear＇ grafted on rootstock of ＇Dull＇ the root, trunk, limb and one-year- old shoots were cut from the plants. The incision was coated with an absorbent cotton ball and a rubber bag for 24 h. The absorbent ball was taken off when it was soaked by xylem apoplastic sap. Petioles and leaf blades were also coated by absorbent balls, then packed in a rubber bag. After extrusion, an absor- bent ball was saturated in xylem apoplastic sap. All absorbent balls were sealed in Buffer tubes. The pH value of samples of the leaf apoplast fluid and xylem excudate was measured by pH indicator strips and microelectrode P15. The leaves used to iron analysis were cleaned with 0.1% sodium dodecyl sulfonate

关 键 词：'库尔勒香梨’ PH 铁素含量 木质部汁液 

分 类 号：S661.2[农业科学—果树学]