不同pH值下丛枝菌根真菌对枳生长及铁吸收的影响

摘要：【目的】本文对营养液不同pH值下丛枝菌根(arbuscular mycorrhiza)真菌地表球囊霉（Glomus versiforme）对枳Poncirus trifoliata]实生苗生长及植株铁营养状况的影响进行了初步研究。【方法】采用盆栽砂培试验，分别施浇pH 5.0、6.0、7.0和8.0的霍格兰营养液（含50 μM Fe-EDTA）；常规方法测定植株生长指标；曲利苯蓝染色法测定菌根侵染率；分光光度法测定叶绿素含量和根系三价铁螯合物还原酶活性；原子吸收分光光度法测定叶片钾和活性铁含量；钒

Effects of arbuscular mycorrhizal fungi on growth and iron uptake of Poncirus trifoliata under different pH

Objective] We studied the effects of arbuscular mycorrhizal fungus ( Glomus versiforme ) on growth and iron uptake of trifoliate orange Poncirus trifoliata ( L. ) Raf. ] at different pH levels of nutrient solution. Methods] P . trifoliata seedlings were grown in substrates watered by nutrient solution with 50 μM. Feethylenediaminetetraacetic acid ( EDTA) at pH values of 5.0, 6.0 (as control ), 7.0 and 8.0 with a sand culture. Mycorrhizal colonization was tested by trypan blue staining method. Chlorophyll concentratration and root Fe (Ⅲ ) chelate reductase activity were determined by spectrophotometer. Potassium and active iron contents were quantified by atomic spectrometry, and phosphorus contents was through phospho-vanado- molybdate colorimetry. Results] The colonization of Giomus versiforme significantly increased the plant height, stem diameter,leaf numbers, and dry mass. Arbuscular mycorrhizal fungus significantly enhanced the accumulation of chlorophyll,active iron, total iron and root Fe(Ⅲ) chelate reductase activityⅢand decreased P/Fe and 50(10P+K)/Fe ratios. All biomass, iron contents and root Fe( Ⅲ ) chelate reductase activities of P . trifoliata seedlings at pH 6.0 level were the maximum both in inoculated and non-inoculated treatments.Conclusion] Arbuscular mycorrhizal fungi could remedy chlorosis caused by iron-deficiency in citrus, and 6.0 was the optimal pH value for the growth of P . trifoliata seedlings.