研究600 mg.L-1多效唑(PP333)浸种对200 mmol.L-1NaCl胁迫处理下麻疯树幼苗相对生长速率(RGR)、干物质积累速率(DMAR)、含水量(WC)、根冠比(R/S)以及叶片电解质渗漏率(EL)、渗透调节能力(OAA)、抗氧化能力、离子分配等的效应。结果表明:与对照相比,PP333浸种处理显著降低植株RGR、叶片SOD和POD活性,显著提高植株DMAR、WC和R/S,显著提高叶片OAA、K+含量和K+/Na+比率;200 mmol.L-1NaCl胁迫下麻疯树幼苗RGR、DMAR、WC、R/S、SOD活性、CAT活性、K+含量和K+/Na+比率均显著下降,而EL、MDA含量、POD活性、Na+和Cl-含量均显著上升;600 mg.L-1PP333浸种处理能显著提高NaCl胁迫下植株的RGR、DMAR、WC和R/S,同时显著降低叶片EL、Na+和Cl-含量,显著提高叶片OAA、SOD和CAT活性,显著提高K+含量和K+/Na+比率,显著降低MDA含量和POD活性。结论:PP333浸种能显著促进麻疯树幼苗的生物量积累,抑制地上部伸长,即矮壮效应,从而大大改善其对盐渍的适应能力,其耐盐性的提高是因为PP333浸种改善了植株的抗氧化能力、渗透调节和离子平衡。
This study evaluated the effects of seed soaking in 600 mg. L-1 paclobutrazol ( PP333 ) on the growth of Jatropha curcas seedlings under salt stress, and the relative growth rate ( RGR), dry matter accumulation rate (DMAR) , water content ( WC ), root/ shoot ratio (R/S) , leaf electrolyte leakage (EL) , osmotic adjustment ability(OAA) , antioxidation and ion distribution in leaf were de- termined. The results obtained were as follows: compared with the control, the treatment of seed soaking in 600 mg. L-1 PP333 significantly decreased RGR, and activities of SOD and POD, and increased DMAR, WC, R/S, and increased OAA, K+, K+/Na+ ratio in leaves. The treatment of 200 mmol.L-1 NaC1 significantly decreased the seedling RGR, DMAR, WC, R/S, SOD activity, CAT activity, K+ content and K+/Na+ ratio, and increased EL, MDA content, POD activity, contents of Na+ and Cl-. However, compared with only NaCl treatment, the plant RGR, DMAR, WC, R/S, and the leaf OAA, SOD activity, CAT activity, K+ content and K+/Na+ ratio also increased, but leaf EL, contents of Na+, Cl- and MDA, and POD activity obviously decreased with PP333 application under NaCl stress. To sum up, seed soaking in 600 mg.L-1 PP333 stimulated J. curcas seedlings' growth obviously, making the plant dwarf and strong, and their salt adaptation was improved remarkably. The above-mentioned stimulation and improvement were due to the improvement of leaf antioxidation, osmotic adjustment and ion homeostasis caused by PP333.