不同浓度5-氨基乙酰丙酸(ALA)浸种对NaCl胁迫下番茄种子发芽率及芽苗生长的影响

Effects of seed soaking with different concentrations of 5-aminolevulinic acid on the germination of tomato(Solanum lycopersicum) seeds under NaCl stress

为探讨外源5-氨基乙酰丙酸(ALA)对NaCl胁迫下番茄种子发芽率及芽苗生长的影响,以‘中杂九号’番茄种子为试材,不同浓度ALA(0、0.1、0.5、1.0、5.0、10.0mg/L)浸种24h后,在0、25、50、100mmol/L NaCl胁迫下,28℃,黑暗培养7d,研究ALA对番茄种子发芽参数(发芽率、发芽势、发芽指数、活力指数、芽苗总鲜重)及胚芽和胚根中的抗氧化酶(超氧化物歧化酶SOD、过氧化物酶POD、过氧化氢酶CAT)活性和丙二醛(MDA)含量的影响。结果表明:非盐胁迫下,ALA浸种使番茄种子的发芽势、发芽指数、活力指数、芽苗总鲜重增加,胚根中SOD、POD活性降低,MDA含量减少;25mmol/L NaCl胁迫能够提高发芽率、活力指数、芽苗总鲜重,而50—100mmol/L NaCl胁迫极显著的降低发芽率、发芽势、发芽指数、活力指数;0.1—0.5mg/L ALA浸种能够提高NaCl胁迫下番茄种子的发芽率、发芽指数、活力指数、芽苗总鲜重和抗氧化酶活性,降低MDA含量,而高浓度ALA(10.0mg/L)浸种导致发芽率、发芽指数、活力指数降低。总之,ALA浸种能够促进番茄种子萌发和芽苗生长,浸种浓度不宜超过5.0mg/L,NaCl胁迫下以0.1mg/L ALA浸种处理效果最佳。

In order to explore the effects of exogenous 5-aminolevulinic acid （ALA） on seeds germination and seedlings growth under NaCl stress, this experiment was conducted by presoaking the tomato seeds （Solanum lycopersicum cv. Zhongza9） with different concentrations of ALA （0, 0.1, 0.5, 1.0, 5.0, 10.0mg/L ） for 24 hours, and training under 0, 25, 50, and 100 mmol/L NaCl stress in growth cabinet at 28℃ for 7 days in darkness. The germination rate （GR）, germination energy （GE）, germination index （GI）, vigor index （VI）, shoot fresh weight （SFW）, root fresh weight （RFW） and antioxidant enzymes （SOD, POD, CAT）activity and malondialdehyde （MDA） content in shoots and roots were emphatically analyzed in this paper. The results showed that： GE, GI, VI, FW of tomato seeds germinated with distilled water are significantly increased in ALA soaking treatment than that in non-ALA treatment, while SOD and POD activity in roots are largely reduced and MDA content decreased. Low concentration of NaC1 （25mmol/L） treatment can improve GR, VI and FW, promote tomato seeds germination; high concentration of NaCl （50--100mmol/L） treatment reduce GR, GE, GI and VI, extremely inhibit seed germination; appropriate concentration of ALA（0.1--0.5mg/L ） presoaking seeds canimprove the GR, GI, GI, FW and antioxidant enzymes activity of tomato seeds, make MDA content decreased, have promoted effects on tomato seeds germination and after germination growth under NaC1 stress; high concentration of ALA （10mg/L） presoaking seeds make GR, GI, VI reduced, inhibit seed germination. In conclusion, presoaking seeds with ALA can promote germination and after germination growth of tomato seeds, soaking concentration should not exceed 5.0mg/L, 0.1 mg/L ALA soaking treatment have the best effects on tomato seeds germination and after germination growth under NaCl stress.