外源水杨酸对高温胁迫下菜豆种子萌发的影响

为研究高温胁迫下菜豆种子的发芽能力,并探讨水杨酸对菜豆种子发芽期热胁迫的缓解作用。以菜豆品种‘A18’种子为试材,分别设置常温对照(CK1)与高温对照(CK2),并在高温下设置4个SA浓度处理组：T1 (0.005 mmol/L)、T2 (0.01 mmol/L)、T3 (0.05 mmol/L)、T4 (0.1 mmol/L),浸种6 h后进行发芽试验与生理试验。对各处理种子在萌发时期的发芽率、发芽指数、种子活力指数及生理指标进行测定。结果显示：常温对照组(CK1)的发芽率和种子活力指数高达(97.61±2.09)%和861.13±81.30。高温对照组（CK2）发芽率和种子活力指数为(56.67±3.33)%和306.50±62.33,较CK1分别下降了41.94%和62.13%。高温下,随SA处理浓度的升高,菜豆种子的发芽率和种子活力指数呈先升后降的趋势,且处理组中T2组表现最好。与CK2相比,T2组菜豆种子的发芽率、发芽指数和种子活力指数分别提高了41.18%、25.33%及67.04%;SOD酶活性提高;可溶性蛋白含量增加;O₂^-.及MDA含量减少。0.01 mmol/L的SA处理可缓解高温带给菜豆种子的不利影响,提高菜豆种子的耐热性。

Exogenous Salicylic Acid: Effects on Seed Germination of Snap Bean Under High Temperature Stress

In order to study the germination ability of snap bean seeds under high temperature stress, and to explore the alleviating effect of salicylic acid (SA) on heat stress of snap bean seeds during germination, the snap bean variety ‘A18’ was used as experimental material, the normal temperature control (CK1) and high temperature control (CK2) were set respectively, four SA concentration treatments were set up at high temperature: T1 (0.005 mmol/L), T2 (0.01 mmol/L), T3 (0.05 mmol/L) and T4 (0.1 mmol/L), and germination test and physiological test were carried out after soaking the seeds for 6 hours. The germination rate, germination index, seed vigor index and physiological indexes of seeds under different treatments were determined. The results showed that the germination rate and seed vigor index of normal temperature control (CK1) were as high as (97.61 ±2.09)% and 861.13 ±81.30. The germination rate and seed vigor index of high temperature control (CK2) were (56.67±3.33)% and 306.50 ±62.33, which were decreased by 41.94% and 62.13% compared with those of CK1. Under high temperature, with the increase of SA concentration, the germination rate and seed vigor index of snap bean seeds increased at first and then decreased, and T2 performed the best. Compared with those of CK2, the germination rate, germination index and seed vigor index of T2 were increased by 41.18%, 25.33% and 67.04%, respectively, SOD activity was improved, the content of soluble protein was increased, and the content of O₂^-. and MDA were decreased. The SA treatment of 0.01 mmol/L can alleviate the adverse effects of high temperature and improve the heat tolerance of snap bean seeds.