8种盐生植物种子萌发特征与NaCl盐度的关系

Study on the relationship between germination characteristics of 8 halophytes and NaCl salinity

耐盐植物的选育是盐渍土地生物改良的关键。通过对13个NaCl盐度梯度下,真盐生植物囊果碱蓬、盐地碱蓬、高碱蓬、盐角草、盐爪爪,泌盐植物大叶补血草、耳叶补血草、黄花补血草8种盐生植物的萌发试验,测定其种子发芽率、发芽势、发芽指数和相对盐害率等指标,研究不同NaCl盐度胁迫对其萌发特性的影响。结果表明:低盐度(50 mmol/L)能促进8种盐生植物的萌发;随着盐度的上升,盐角草、盐地碱蓬、囊果碱蓬、高碱蓬表现出较强的萌发耐盐性,发芽势和发芽指数优于其他植物;盐角草的萌发耐盐性最佳,在1000 mmol/L盐度下萌发率仍能达到54.0%。进一步通过S型生长曲线和线性模型分析得出,8种植物为对抗逆境大致分为"快速型"和"缓慢型"两种萌发策略;随盐度的升高,初始萌发时间和萌发高峰时间均不同程度的向后推迟。盐度≤200 mmol/L时,囊果碱蓬的萌发占据优势,其萌发速率大于其他植物,且差异显著;中盐度400 mmol/L左右时,盐地碱蓬和盐角草萌发最快,二者无显著差异;盐度≥600 mmol/L时,盐角草萌发速率较快,相比其他植物差异显著。泌盐植物的萌发耐盐适宜浓度和耐盐极限浓度均低于真盐生植物。8种植物均有作为氯化物为主盐渍土地区生物改良材料的潜力。

The breeding of salt tolerant plants is the key to the biological remediation of saline soil.We conducted a germination experiment of euhalophytes and recretohalophytes under 13 NaCl gradients,including the euhalophytes:Suaeda physophora Pall.,Suaeda salsa(L.)Pall.,Suaeda altissima(L.)Pall.,Salicornia europaea L.,Kalidium foliatum(Pall.)Moq.and recretohalophytes:Limonium gmelinii(Willd.)Kuntze,Limonium otolepis(Schrenk)Kuntze,Limonium aureum(L.)Hill.To investigate the responses of germination characteristics to salinity stress by determining the seed germination rate,germination potential,germination index and relative salt damage rate.The results showed that low salinity(NaCl=50 mmol/L)could promote the germination of 8 halophytes.With the increase of salinity,S.europaea,S.salsa,S.physophora,S.altissima presented stronger salt tolerance in germination,and its germination potential and germination index were higher than others.S.europaea had the highest salt tolerance,and its germination rate even reached 54.0%under 1000 mmol/L.The 8 plants could be roughly divided into aggressive and cautious germination strategies based on S-shaped growth curve and linear model.With the increase of salinity,the initial germination time and the peak time of germination were delayed in varying degrees.When salinity≤200 mmol/L,the germination of S.physophora was dominant.Its germination rate was higher than that of other plants and the difference was significant.When the medium salinity was about 400 mmol/L,S.salsa and S.europaea germinate fastest,and there was no significant difference between the two.When the salinity was≥600 mmol/L,the germination rate of S.europaea was faster,which was significantly different from other plants.The salt tolerance concentration and salt tolerance limit concentration of recretohalophytes were lower than euhalophytes.Our results indicated that 8 plants had the potential to be used as ecological restoration materials in saline soil areas dominated by chloride.