张睿, 封晓辉, 吴玉洁, 孙琦, 李静, 李劲松, 刘小京. 长穗偃麦草(Thinopyrum ponticum)幼苗对盐旱胁迫的生理响应[J]. 中国生态农业学报 (中英文), 2022, 30(11): 1795−1806. DOI: 10.12357/cjea.20220185
引用本文: 张睿, 封晓辉, 吴玉洁, 孙琦, 李静, 李劲松, 刘小京. 长穗偃麦草(Thinopyrum ponticum)幼苗对盐旱胁迫的生理响应[J]. 中国生态农业学报 (中英文), 2022, 30(11): 1795−1806. DOI: 10.12357/cjea.20220185
ZHANG R, FENG X H, WU Y J, SUN Q, LI J, LI J S, LIU X J. Interactive effects of drought and salt stresses on the growth and physiological characteristics of Thinopyrum ponticum[J]. Chinese Journal of Eco-Agriculture, 2022, 30(11): 1795−1806. DOI: 10.12357/cjea.20220185
Citation: ZHANG R, FENG X H, WU Y J, SUN Q, LI J, LI J S, LIU X J. Interactive effects of drought and salt stresses on the growth and physiological characteristics of Thinopyrum ponticum[J]. Chinese Journal of Eco-Agriculture, 2022, 30(11): 1795−1806. DOI: 10.12357/cjea.20220185

长穗偃麦草(Thinopyrum ponticum)幼苗对盐旱胁迫的生理响应

Interactive effects of drought and salt stresses on the growth and physiological characteristics of Thinopyrum ponticum

  • 摘要: 盐渍土主要分布于干旱、半干旱地区, 植物的生长同时受到旱和盐的胁迫。本研究以长穗偃麦草(Thinopyrum ponticum)为材料, 采用盆栽方法, 探究了盐、旱及其互作对长穗偃麦草幼苗生长和生理特性的影响, 以期为长穗偃麦草在盐碱地的种植提供理论依据。试验设置4个土壤含盐量水平: 0 g·kg−1、4 g·kg−1、8 g·kg−1和12 g·kg−1; 3个干旱水平: 土壤含水量为田间持水量的75%~85% (常规灌水)、55%~65% (中度干旱)和35%~45% (重度干旱), 共12个处理, 以常规灌水和无NaCl添加为对照。试验测定了长穗偃麦草幼苗的生物量及叶绿素SPAD值、光合参数、抗氧化物酶活性和地上、地下部Na+、K+含量。结果表明: 干旱胁迫和盐胁迫均可使长穗偃麦草的生长受到抑制, 但盐旱互作可提高根/冠比, 长穗偃麦草仍可在重度干旱和高盐胁迫(12 g·kg−1)下存活。干旱或盐胁迫使长穗偃麦草叶绿素含量、净光合速率、气孔导度和蒸腾速率下降, 但这些指标在盐旱互作下高于常规灌水下的同一盐分处理。适当的盐分和干旱胁迫提高长穗偃麦草叶片SOD、POD、CAT活性, 高盐则降低; 重度干旱和高盐胁迫提高了叶片MDA含量。长穗偃麦草地上部Na+、K+含量和K+/Na+比高于根部; 干旱和盐分胁迫下, 长穗偃麦草根部和地上部Na+含量增加, K+含量减少但依然维持在较高水平, 干旱处理显著提高了盐胁迫下根部Na+含量, 但根部K+/Na+相对稳定, 地上部K+/Na+显著下降。上述结果表明, 长穗偃麦草在重度干旱和高盐胁迫下的存活特征可能与其具有发达的根系、高根/冠、完善的抗氧化系统以及根系Na+积累和根系稳定的K+/Na+有关, 但要获得一定的生物量仍需要适度的干旱和低盐条件。

     

    Abstract: Saline soils are mainly distributed in arid and semi-arid regions where both soil salt content and drought affect plant growth at the same time. Therefore, soil pot experiments were conducted to study the effects of soil salt content, drought, and their interactions on the growth and physiological characteristics of Thyropyrum ponticum seedlings to understand the adaptability of T. ponticum seedlings in saline soil areas and to provide a theoretical basis for the population establishment of T. ponticum in such areas. Twelve treatments, including four soil salinity levels (0, 4, 8, and 12 g∙kg−1 NaCl) and three soil moisture levels (75%–85%, 55%–65%, and 35%–45% of field capacity) were used. Shoot and root dry weights, leaf chlorophyll contents (SPAD values), leaf photosynthetic parameters, leaf antioxidant enzymes activities, and Na+ and K+ contents in shoots and roots were measured. The results showed that the growth of T. ponticum was significantly inhibited under drought stress or salt stress, whereas root/shoot ratios increased under the interactions of soil salt and drought stress, and the plants could still survive under 35%–45% field capacity with 12 g∙kg−1 NaCl. Drought and salt stress significantly reduced leaf chlorophyll content, net photosynthetic rate, stomatal conductance, and transpiration rate, whereas these parameters were increased under high salinity levels under moderate drought stress (55%–65% of field capacity) compared with those under normal irrigation. Moderate drought or salt stress increased the activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT), but these activities were decreased under 12 g∙kg−1 NaCl. The leaf malondialdehyde (MDA) content increased under extreme drought or salt stress. In terms of ion accumulation, Na+ and K+ contents, and K+/Na+ ratio were higher in shoots than in roots. Roots and shoots Na+ contents were increased with decreasing soil water content or increasing soil salinity, whereas K+ contents decreased but remained relatively high. Regarding salt-drought interactions, drought treatment could reduce salt stress in plants by promoting the accumulation of Na+ in roots. Under drought stress, root Na+ content was further increased by increasing soil salinity, while root K+/Na+ ratio remained stable and shoot K+/Na+ ratio was significantly decreased. The above results indicate that T. ponticum can survive under high drought and salt conditions, possibly due to its strong root system, higher root/shoot ratio, relatively complete antioxidant enzyme system, Na+ accumulation, and stable K+/Na+ ratio in roots. Although T. ponticum can survive under high drought and salt conditions, the high production of biomass still requires lower soil salinity and moderate drought conditions because the shoot biomass significantly decreases with the increase in soil salinity or decrease in soil moisture.

     

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