盐胁迫对4种短命植物种子萌发及植株生长的影响

以新疆北部4种十字花科短命植物为材料,研究不同浓度NaCl胁迫下其种子萌发及植株生长特性,以明确它们的耐盐性强弱。结果显示:(1)随着NaCl浓度的增加,4种植物种子萌发率、萌发指数和相对萌发率均不同程度下降,而相对盐害率则逐渐升高,并以绵果荠的耐盐性最好,其在300 mmol.L-1NaCl胁迫下仍有22.22%的萌发率。(2)4种植物的生长在50~150 mmol.L-1NaCl胁迫下没有受到明显抑制,在200 mmol.L-1浓度下受不同程度的抑制,而在300 mmol.L-1NaCl胁迫下抑制作用更严重,其中绵果荠在各浓度处理下长势均最好,能够在300 mmol.L-1NaCl胁迫下存活10 d。(3)在盐胁迫条件下,4种植物细胞质膜透性不同程度增加,而叶片相对含水量和光合色素含量均不同程度降低,并以绵果荠各项指标的变化幅度最小。可见,4种新疆短命植物种子萌发和植株生长均受到盐胁迫的伤害,但它们的耐盐阈值明显不同,并以绵果荠的耐盐性最强。

Seed Germination and Plant Growth of Four Ephemeral Species under Salt Stress

In this paper,with four species of Xinjiang ephemeral plants of Brassicacea as material,the effect of salt stress on seed germination and plant growth characters were studied and salt tolerance ability of them were compared.The result showed that seed germination rate,germination index and relative germination rate of all four materials were decreased to different extents.The relative salt damage rates were increased progressively with increasing of NaCl concentrations and Lachnoloma lehmannii has the best salt tolerance ability with about 22.22% seeds germinated under 300 mmol·L-1 NaCl stress.The growth inhibition effect of 50～150 mmol·L-1 NaCl stress to four species were not significant,but under 200 mmol·L-1 NaCl solution those plants growth were suppressed to different extents,and the suppression is more obvious at 300 mmol·L-1 NaCl concentration.The growth status of L.lehmannii in the all salt solution was the best among them.It is still alive for 10 d under 300 mmol·L-1 salinity.Under salt stress,leaf membrane permeabilities of four species were increased.The relative water contents and photosynthetic pigment contents were decreased with different extents,but the variation of that index of L.lehmannii was the lowest.In conclusion,the seed germination and plant growth of four ephemeral species in Xinjiang were suffered setback under salt stress,but their salt tolerance were obviously different and the salt tolerance of L.lehmannii was the strongest.