SHK-6对干旱胁迫下大豆叶片生理功能的作用

Effects of Plant Growth Regulator SHK-6 on Physiological Function of Soybean Leaves under Water Deficiency

以“垦农5号”为材料,在盆栽条件下,比较研究了植物生长调节剂SHK-6在干旱胁迫和正常水分条件下对大豆叶片光合作用、同化物运输、抗氧化酶系统以及渗透物质的影响。结果表明(1)SHK-6显著提高干旱条件下叶片水势、Fv/Fm、叶绿素含量和光合速率;同时也显著提高在正常水分条件下叶片光合速率,但对叶片水势、Fv/Fm和叶绿素含量的影响较小。还显著提高了不同水分条件下叶片RuBP羧化酶、PEP羧化酶的活性和SPS的活性。(2)显著提高干旱条件下叶片POD、SOD酶活性,促进叶片游离脯氨酸和可溶性糖积累,降低MDA的含量和减小叶片相对电导率。(3)提高14C同化产物的向外运输,显著增加了同化物在根、根瘤和荚中的积累及同化产物的输出速率。(4)显著提高籽粒、根和根瘤重,而不提高茎和叶的干重。

Drought is a major abiotic stress for soybean production. Various agronomic and physiological practices are applied to minimize the adverse effect of moisture stress on soybean growth. Plant growth regulators, both natural and synthetic, are widely applied to agricultural crops as a means of crop production improvement. There is evidence that plant growth regulators increase stress resistance of plants. The effect of SHK-6 （80% Diethyl aminoethyl hexanoate and Mepiquat chloride, its ratio is 1 ： 5） on photosynthesis, assimilate distribution, antioxidant enzymes and seeds yield of soybean （ Glycine max L. ）, cv. Kennong 5, was studied under normal and water deficient conditions. SHK-6 was sprayed on leaves at R1 at 100 mg· L^- 1, and with water spraying as control. Two levels of soil moisture （75% and 40% for wellwatered and water-deficient, respectively） were applied at R3. The results indicated that the seed yield, roots biomass and nodules biomass were significantly increased, but the biomass of leaves and stems was not affected by SHK-6 under different water supply conditions. The ^14C assimilate in roots, nodules and pods were significantly accumulated and the ^14C transportation rate was increased by SHK-6 under both water supply conditions. The leaf water potential, chlorophyll content, Fv/Fm, Pm, and activities of RuBPcase, PEPCase and SPS were significantly increased by SHK-6 under water deficiency. In addition, acitivies of leaf POD and SOD, contents of soluble sugar and proline were increased, while MDA content and electrical conductivity were decreased by SHK-6. It was concluded that SHK-6 minimized the yield loss caused by water deficiency.