水涝胁迫对不同土壤盐碱度下甜菜幼苗生长及光合特性的影响

为探究水涝胁迫对不同土壤盐碱度下甜菜幼苗生长的影响,验证甜菜在水涝逆境中的生长规律,评估水涝胁迫对盐碱地甜菜种植的影响,以甜菜‘SV1433’为供试品种,以微酸性黑土为基础利用NaCl、Na₂SO₄、Na₂CO₃、NaOH调节土壤盐碱度,采用室内土培法,设置微酸土、盐渍土、盐碱土3个土壤盐碱梯度下对照及水涝胁迫共6组处理。结果发现,播种9天后出苗结束,微酸土中甜菜出苗较快,优于盐渍土及盐碱土;播种26天后收苗,在微酸土、盐渍土、盐碱土3种土壤盐碱度下,水涝胁迫比对照植株鲜重分别降低40.7%、26.9%、25.2%,干重分别降低41.1%、29.9%、24.8%,株高分别下降20.4%、19.1%、16.3%,表明随土壤盐碱度升高水涝胁迫对甜菜幼苗鲜重、干重、株高影响逐渐降低;水涝胁迫下幼苗根面积及叶面积显著降低,植株叶长显著下降,叶片净光合速率、蒸腾速率、叶片气孔导度显著降低,表现出水涝胁迫下盐碱土中甜菜幼苗生长较好,优于盐渍土及微酸土。

Effects of Waterlogging Stress on Growth and Photosynthetic Characteristics of Sugar Beet Seedlings Under Different Soil Salinity and Alkalinity

The study aims to explore the effects of different soil salinity and alkalinity on the growth and photosynthetic characteristics of sugar beet seedlings under waterlogging stress, and to verify the growth law of sugar beet under waterlogging stress and provide a theoretical basis for the evaluation of the impact of waterlogging stress on sugar beet planting in saline-alkali land. We used ‘SV1433’ as the research material, and NaCl, Na₂SO₄, Na₂CO₃ and NaOH to adjust soil salinity and alkalinity for three soil saline-alkali gradients, which were slightly acidic soil, saline soil and salinity-alkalinity soil. Indoor soil culture was carried out with six treatments, including the three soil saline-alkali gradients under both CK (without waterlogging stress) and waterlogging stress. The results showed that the seedling emergence of sugar beet in slightly acidic soil was faster than that in saline soil and saline-alkali soil after 9 days of sowing. After 26 days of sowing, at three soil saline-alkali gradients of slightly acidic soil, saline soil and saline-alkali soil under waterlogging stress, compared with CK, the fresh weight decreased by 40.7%, 26.9% and 25.2%, respectively, the dry weight decreased by 41.1%, 29.9% and 24.8%, respectively, and the plant height decreased by 20.4%, 19.1% and 16.3%, respectively. It was shown that the effects of waterlogging stress on fresh weight, dry weight and plant height of sugar beet seedlings decreased gradually with the increase of soil salinity and alkalinity. Under waterlogging stress, the area of seedling root and leaf and the leaf length decreased significantly, so did the net photosynthetic rate (Pn), transpiration rate (Tr) and stomatal conductance (Gs) of leaves, indicating that the growth of sugar beet seedlings in saline-alkali soil was better than that in saline and slightly acidic soil under waterlogging stress.