亚精胺浸种对小麦幼苗抗渗透胁迫能力的影响

Effect of Seed Soaking with Spermidine on Tolerance of Wheat (Triticum aestivum L.) Seedlings to Osmotic Stress

研究了渗透胁迫下亚精胺(spermidine,Spd)浸种后,小麦品种豫麦18号(抗旱性较强)和扬麦9号(抗旱性较弱)幼苗的相对干重增长速率(relative dry weight increase rate,RDWIR)、叶片相对含水量(leaf relative water content,LRWC)、叶片相对电解质渗漏率(leaf relative electrolyteleakage,LREL)和叶片内Spd含量的变化,结果表明,胁迫第7天,抗旱性弱的扬麦9号小麦幼苗的LREL的上升幅度明显大于抗旱性强的豫麦18号,其叶片内Spd含量的升幅则明显小于豫麦18号;而豫麦18号幼苗的RDWIR和LRWC的下降幅度明显小于扬麦9号。Spd浸种处理渗透则明显抑制在胁迫条件下扬麦9号幼苗RDWIR,LRWC的下降和LREL的增加,促进叶片内Spd含量的增加。这些结果表明,Spd浸种通过提高渗透胁迫下小麦(特别是抗旱性较弱的品种)幼苗叶片中Spd的水平,从而增强小麦幼苗的抗渗透胁迫能力,促进其生长。

The changes in relative dry weight increase rate（RDWlR）,leaf relative water content （LRWC） ,leaf relative electrolyte leakage （LREL） and spermidine content were investigated in seedling leaves of two wheat（Triticum aestivum L. ） cultivars, Yumai 18 （drought-tolerant） and Yangmai 9 （drought-sensitive） under osmotic stress. On the 7th day, after polyethylene glycol （PEG）-6 000 treatment,LREL of seedlings of Yangmai 9 increased more significantly than that of Yumai 18,while the Spd content in latter increased more significantly; RDWIR and LRWC of seedlings of Yangmai 9 decreased more significantly than that of Yumai 18. Under osmotic stress, treatment of seed-soaking with Spd resulted in the increases in RDWIR,LRWC and Spd,in con- cert with an decrease in LREL of seedlings of Yangmai 9. The results suggested that Spd see.d- soaking could enhance growth and the tolerance of wheat seedlings, especially of the drought-sen- sitive cultivar, to osmotic stress, via increasing Spd contents in seedling leaves.