盐碱胁迫对2个葡萄品种光合及荧光特征的影响(英文)

Saline-alkaline Stress on Photosynthesis,Chlorophyll a Fluorescence of Two Cultivars of Grape

土壤盐碱胁迫是限制作物生产力的世界性问题。很多研究关注盐分胁迫或者碱胁迫单因子对作物的影响,盐碱混合胁迫的研究较少。本研究按照研究区自然土壤盐碱主要成分和组成比例(NaCl、Na2SO4、Na2CO3质量混合比例为1∶0.5∶0.5),设置了不同浓度的盐碱处理(0,100,200,400 mmol/L),模拟无胁迫、轻度胁迫、中度胁迫和重度胁迫。试验材料为2个葡萄品种克瑞生和摩尔多瓦的3年生实生苗。研究结果表明,轻度盐碱处理能在一定程度上改善2个品种的光合能力。高浓度盐碱胁迫条件下,两品种的净光合速率和气孔导度数值均比对照提高,光合-光响应曲线趋势表现一致。对于克瑞生,光合速率的提高得益于气孔导度和蒸腾速率的提高,但是较低的PSⅡ光化学效率降低了这种惠益。对于摩尔多瓦,较高的PSⅡ光化学效率帮助了其保持较为稳定的净光合速率。2个品种显示了对盐碱胁迫的不同适应性机制。

Soil salinization and alkalization is a worldwide problem limit productivity of horticultural crops.Many studies have focused on responses of crop to either salt or alkaline stress.However,seldom have studies focused on the effects of this mixed stress.In our experiment in Yinchuan,Northern China,the mixtures of three salts（NaCl,Na2SO4,Na2CO3 with proportion of 1 ∶ 0.5 ∶ 0.5） in various concentrations（0,100,200,400 mmol/L） were used to simulate a range of soil natural salt-alkaline conditions.Three-year-old seedlings of two grape cultivars,Crimson（CRS） and Moldova（MDW）,widely spread in the world,were planted in open field conditions under the treatments.The results indicate that light saline-alkaline treatments enhanced the photosynthetic capability in two grape cultivars.For the high concentration,net photosynthetic rate（Pn） and stomatal conductance（Gs） of CRS or MDW increased.In Pn light response curves,the same tendency was observed.For CRS,the increase of Pn benefited from high Gs and transpiration rate（Tr）,however,a low Fv/Fm decreased such impacts.For MDW,high Fv/Fm helpfully maintain a relatively stable Pn.The two cultivars demonstrated different suitability regime to saline-alkaline stress.