外源水杨酸对盐胁迫下大黄种子萌发及幼苗生长的影响

该研究以掌叶大黄、唐古特大黄和药用大黄种子为材料，采用双层滤纸培养法，设置系列浓度NaCl (0、100、150、200、250 mmol/L) 胁迫试验，以及系列浓度水杨酸(SA)溶液(0、50、100、150、200、250 mg/L)拌种和浸种后盐胁迫实验，测定3种大黄种子萌发及幼苗生长指标，揭示外源水杨酸对盐胁迫下大黄种子萌发及幼苗生长的影响。结果显示：(1)随NaCl浓度增大3种大黄种子的发芽率均呈直线下降趋势，且子叶、胚轴、根和苗等生长均受到强烈抑制。(2)在拌种条件下， 200 mmol/L NaCl胁迫下掌叶大黄苗长在200 mg/L SA处理下受到显著促进； 200 mmol/L NaCl浓度盐胁迫下唐古特大黄种子发芽率在250 mg/L SA处理下受到显著抑制；100 mmol/L NaCl胁迫下药用大黄种子发芽势在200 mg/L SA处理下受到显著抑制，其发芽率在150 mg/L SA处理下得到显著抑制，其苗长在250 mg/L SA处理下受到显著抑制。(3)在浸种条件下， 200 mmol/L NaCl胁迫下掌叶大黄种子发芽率在50 mg/L SA处理下显著提高，其幼苗根长和苗长的生长在250 mg/L SA处理受到显著促进；200 mmol/L NaCl胁迫下唐古特大黄种子的发芽势在200 mg/L SA处理下得到显著促进，其幼苗根和苗的生长在50 mg/L SA处理下得到显著促进；100 mmol/L NaCl 胁迫下药用大黄根和苗的生长在100 mg/L SA处理下均得到显著促进。研究表明，3种大黄种子和幼苗对盐胁迫的响应趋势一致，但对不同浓度SA拌种和浸种的响应有较大差异。

Effect of Exogenous Salicylic Acid on Germination and Seedling Growth of Rhubarb under Salt Stress

The seeds of Rheum palmatum, R. tanguticum and R. officinale were cultured with double layer filter paper and subjected to a series of NaCl stress concentrations (0, 100, 150, 200, 250 mmol/L), and salicylic acid (SA) solution of a series of concentrations (0, 50, 100, 150, 200, 250 mg/L) were used for seed dressing or soaking to carry out salt stress experiments. We measured seed germination and seedling growth indexes of three kinds of rhubarb to reveal the effects of exogenous salicylic acid on rhubarb seed germination and seedling growth under salt stress. Overall, the results showed that: (1) seed germination rates of three rhubarbs decreased with the increasement of NaCl concentration. The cotyledon, hypocotyl, root and seedlings length were all strongly inhibited with the increasement of NaCl concentration. (2) Under the condition of seed dressing, 200 mg/L SA treatment promoted the seedling growth of R. palmatum under 200 mmol/L NaCl stress; 250 mg/L SA inhibited the germination rate of R. tanguticum seeds under 200 mmol/L NaCl stress; 200 mg/L SA inhibited the germination potential of R. officinale seeds under 100 mmol/L NaCl, 150 mg/L SA inhibited the germination rate of rhubarb seeds under 100 mmol/L NaCl stress, 250 mg/L SA inhibited the seedling growth of rhubarb seedlings under salinity stress. (3) Under seed soaking conditions, 50 mg/L SA increased the germination rate of R. palmatum seeds under 200 mmol/L NaCl stress, and the growth of roots and seedlings was promoted by 250 mg/L SA treatment, and 250 mg/L SA promoted the growth of roots and seedlings of R. palmatum seedlings under 200 mmol/L NaCl concentrations; 200 mg/L SA promoted germination potential of R. tanguticum under 200 mmol/L NaCl stress, and the growth of roots and seedlings was promoted by 50 mg/L SA treatment; 50 mg/L SA promoted root and seedling growth of R. tanguticum under 200 mmol/L NaCl stress; 100 mg/L SA promoted the growth of roots and seedlings of R. officinale under 100 mmol/L NaCl stress. Therefore, it can be concluded that the three kinds of rhubarb seeds had the same response trends to salt stress, but had great differences in response to seed dressing and seed soaking with different concentrations of SA.