日本曲霉产生的黑麦酮酸F对玉米的化感作用

Allelopathic effects of secalonic acid F produced by Aspergillus japonicus on Zea mays

日本曲霉 (Aspergillusjaponicus)是土壤和谷物种子表面的一种常见真菌 .研究结果表明 ,日本曲霉所产生的大量黑麦酮酸F(SAF)对玉米 (Zeamays)有很强的化感作用 ,低浓度显著促进玉米幼苗生长 ,高浓度则抑制 .在 0 .0 375mmol·L-1SAF下 ,玉米幼苗根长增长 31.7% ,根数量增加 13.2 % ,根活力提高4 .73倍 ,并促进玉米对P、K、Ca、Mg、S等 5种营养元素的吸收 .高浓度SAF(0 .3mmol·L-1)下玉米根活力受抑制 (72 .1% ) ,根对N、P、K、Ca、Mg、Fe等营养元素的吸收也受抑制 .0 .6mmol·L-1的SAF下根完全失去活力 .电镜观察表明 ,有SAF的情况下玉米叶绿体片层结构模糊、混乱 ,双层膜不完整 .

Aspergillus japonicus Saito is a common soil-borne fungus, and exists on the surface of some cereal crop seeds. Secalonic acid F (SAF) abstract is the main allelochemical from the fungus. Bioassays showed that SAF significantly stimulated the seedling growth of corn ( Zea mays L.) abstract at a concentration of 0.0375 mmol·L -1 . The root length, root numbers and root oxidation activities increased by 31.7%, 13.2%, and 373%, respectively. Secalonic acid F also increased the nutrient absorption of P, K, Ca, Mg, and S at the same concentration. However, SAF inhibited the seedling growth of corn at concentrations of 0.3 mmol·L -1 and 0.6 mmol·L -1 . The root length, root dry weight, and shoot length were inhibited by 27.7%, 39.1% and 35.8% by 0.3 mmol·L -1 of SAF, and root activities were inhibited by 72.1% and 100% by 0.3 mmol·L -1 and 0.6 mmol·L -1 of SAF, respectively. The nutrient absorption of N, P, K, Ca, Mg and Fe was reduced when the corn seedlings were treated with 0.3 mmol·L -1 SAF. Transmission electron microscope observations showed that the corn treated with 0.3 mmol·L -1 of SAF had a swelling and disorderly arrangement chloroplast, and the stratiform structure of chloroplast became unconspicuous.