水培条件下NaCl胁迫对2个棉花品种苗期生长和生理特征的影响

Effects of NaCl Stress on the Growth and Physiological Characteristics of Two Cultivars of Cotton under Hydroponic Conditions

为探究水培条件下新陆早52号和新陆早74号棉花苗期对不同程度盐胁迫的响应,设置Hoagland全营养液中添加0、70、170、270 mmol/L NaCl处理,以蒸馏水处理作对照,对棉花苗期生长及生理指标进行测定。结果表明,与蒸馏水处理相比,0 mmol/L NaCl处理两个棉花品种均显著促进了生长指标值的增加,且新陆早52号各项指标增加值高于新陆早74号。随培养时间和NaCl浓度的增加,与0 mmol/L NaCl处理相比,新陆早52号株高降低15.4%~79.7%(P<0.05),叶面积指数降低12.6%~57.1%(P<0.05),SPAD值降低9.0%~78.3%(P<0.05),各器官干生物量增长量显著降低;新陆早74号棉花的株高降低18.7%~51.8%(P<0.05),叶面积指数降低6.5%~49.0%(P<0.05),SPAD值降低9.8%~84.1%(P<0.05),各器官干生物量增长量显著降低。相同处理下,新陆早52号受抑制程度低于新陆早74号,70 mmol/L NaCl处理新陆早52号第21天后停止光合作用并死亡,而新陆早74号在第14天停止光合作用并死亡,表明新陆早52号在应对NaCl胁迫上更具优势。

In order to explore the response of the cotton Xinluzao 52 and the cotton Xinluzao 74 to different levels of salt stress under hydroponic conditions,the growth and physiological indexes of cotton during the seedling stage were measured under distilled water,0 mmol/L(Hoagland total nutrient solution),70 mmol/L,170 mmol/L,270 mmol/L NaCl stress.The results showed that 0 mmol/L treatment significantly increased the growth indexes of two kinds of cotton compared with distilled water treatment,and the growth rate of each index of Xinluzao 52 was higher than that of Xinluzao 74.With the increase of culture time and NaCl concentration,compared with 0 mmol/L NaCl,the height of Xinluzao 52 was significantly decreased by 15.4%-79.7%(P<0.05),the leaf area index was significantly decreased between 12.6%-57.1%(P<0.05),the SPAD value was significantly decreased between 9.0%-78.3%(P<0.05),and the dry biomass of each organ was significantly decreased.The plant height,leaf area index and SPAD value of Xinluzao 74 cotton decreased significantly between 18.7%-51.8%(P<0.05)compared with the control between 6.5%-49.0%(P<0.05),the SPAD value decreased between 9.8%to 84.1%(P<0.05)and dry biomass growth in each organ was significantly reduced.The inhibition degree of Xinluzao 52 was lower than that of Xinluzao 74 under the same treatment.Xinluzao 52 stopped photosynthesis and died after 21 days under the 70 mmol/L NaCl treatment,while Xinluzao 74 stopped photosynthesis and died after 14 days,indicating that Xinluzao 52 was more advantageous in coping with NaCl stress.