Waqas Muhammad Ahmed, Khan Imran, Akhter Muhammad Javaid, Noor Mehmood Ali, Ashraf Umair
Department of Agronomy, University of Agriculture, Faisalabad, 38040, Pakistan.
Institute of Crop Science, Chinese Academy of Agricultural Sciences, Key Laboratory of Crop Physiology and Ecology, Ministry of Agriculture, Beijing, 100081, China.
Environ Sci Pollut Res Int. 2017 Apr;24(12):11459-11471. doi: 10.1007/s11356-017-8768-0. Epub 2017 Mar 18.
Chilling stress hampers the optimal performance of maize under field conditions precipitously by inducing oxidative stress. To confer the damaging effects of chilling stress, the present study aimed to investigate the effects of some natural and synthetic plant growth regulators, i.e., salicylic acid (SA), thiourea (TU), sorghum water extract (SWE), and moringa leaf extract (MLE) on chilling stress tolerance in autumn maize hybrid. Foliar application of growth regulators at low concentrations was carried out at six leaf (V6) and tasseling stages. An increase in crop growth rate (CGR), leaf area index (LAI), leaf area duration (LAD), plant height (PH), grain yield (GY), and total dry matter accumulation (TDM) was observed in exogenously applied plants as compared to control. In addition, improved physio-biochemical, phenological, and grain nutritional quality attributes were noticed in foliar-treated maize plots as compared to non-treated ones. SA-treated plants reduced 20% electrolyte leakage in cell membrane against control. MLE and SA were proved best in improving total phenolic, relative water (19-23%), and chlorophyll contents among other applications. A similar trend was found for photosynthetic and transpiration rates, whereas MLE and SWE were found better in improving CGR, LAI, LAD, TDM, PH, GY, grains per cob, 1000 grain weight, and biological yield among all treatments including control. TU and MLE have significantly reduced the duration in phenological events of crop at the reproductive stage. MLE, TU, and SA also improved the grain protein, oil, and starch contents as compared to control. Enhanced crop water productivity was also observed in MLE-treated plants. Economic analysis suggested that MLE and SA applications were more economical in inducing chilling stress tolerance under field conditions. Although eliciting behavior of all growth regulators improved morpho-physiological attributes against suboptimal temperature stress conditions, MLE and SA acted as leading agents which proved to be better stress alleviators by improving plant physio-biochemical attributes and maize growth.
低温胁迫通过诱导氧化应激，急剧阻碍了田间条件下玉米的最佳生长性能。为了减轻低温胁迫的破坏性影响，本研究旨在探究一些天然和合成植物生长调节剂，即水杨酸（SA）、硫脲（TU）、高粱水提取物（SWE）和辣木叶提取物（MLE）对秋玉米杂交种耐低温胁迫的影响。在六叶期（V6）和抽雄期对生长调节剂进行低浓度叶面喷施。与对照相比，外源施用植物生长调节剂的植株的作物生长速率（CGR）、叶面积指数（LAI）、叶面积持续期（LAD）、株高（PH）、籽粒产量（GY）和总干物质积累量（TDM）均有所增加。此外，与未处理的玉米地块相比，叶面处理的玉米地块在生理生化、物候和籽粒营养品质属性方面有所改善。与对照相比，SA处理的植株细胞膜电解质渗漏减少了20%。在所有处理中，MLE和SA在提高总酚含量、相对含水量（19 - 23%）和叶绿素含量方面表现最佳。光合速率和蒸腾速率也呈现类似趋势，而在包括对照在内的所有处理中，MLE和SWE在提高CGR、LAI、LAD、TDM、PH、GY、每穗粒数、千粒重和生物产量方面表现更佳。TU和MLE显著缩短了作物生殖阶段的物候期持续时间。与对照相比，MLE、TU和SA还提高了籽粒蛋白质、油和淀粉含量。在MLE处理的植株中还观察到作物水分生产率提高。经济分析表明，在田间条件下，施用MLE和SA在诱导耐低温胁迫方面更具经济性。尽管所有生长调节剂的诱导行为都改善了植株在次优温度胁迫条件下的形态生理属性，但MLE和SA起到了主导作用，通过改善植物生理生化属性和玉米生长，被证明是更好的胁迫缓解剂。
