重度盐胁迫下12个地被草种萌发期的耐盐性比较

Comparison of salt tolerance during the germination period of 12 grass species under severe salt stress

为了筛选出适宜在滨海盐碱地生长的草种,以草地早熟禾(Poa pratensis)、高羊茅(Festuca arundinacea)、多年生黑麦草(Lolium perenne)等为试验材料,测定重度盐胁迫(NaCl浓度300 mmol·L^–1,MgSO4浓度50 mmol·L^–1)对地被草种萌发期发芽指标、生长指标和根系指标的影响。结果显示,多年生黑麦草、高羊茅两个较耐盐草种在重度盐胁迫下的发芽盐害率不超过30%,抑制作用不明显,而苗长和根长盐害率超过50%,抑制作用明显;在重度盐胁迫下,草种根系总长度、根系总表面积、根头数盐害率超过50%;剪股颖(Agrostis)和三叶草(Trifolium)的根系平均直径盐害率在0~100%。重度盐胁迫下耐盐性较高的3个草种依次为多年生黑麦草、高羊茅和中华羊茅(Festuca sinensis)。多年生黑麦草耐盐性较高的品种有伽马、绅士和百乐门;高羊茅耐盐性较高的品种有火凤凰2号、百万达Ⅱ和耐寒;三叶草属耐盐性较高的品种有红三叶多莉、白三叶超级惠亚和绛三叶樱桃;草地早熟禾耐盐性较高的品种有优异(白)、巴润和抢手股;剪股颖耐盐性较高的品种有A-1、克罗米、羚羊和高地。

In order to screen grass species suitable for planting in coastal areas characterized by saline soils,we selected a range of grasses,including Poa pratensis,Festuca arundinacea,and Lolium perennia,as materials to determine their germination indices,growth dynamics,and root systems under salt stress induced by 300 mmol·L^–1 NaCl and 50 mmol·L^–1 MgSO4 salt solutions applied via moistened filter paper.The results revealed that the two species L.perenne and F.arundinacea had the highest salt tolerance.Although the reduction in grass germination under salt stress was no higher than20%and the effects were non-significant,the suppression of shoot and root growth was greater than 50%compared with that of control plants(P<0.05).Total root system length,total root system areas,and lateral root number were all reduced by more than 50%.For Agrostis and Trifolium,the reduction in the average diameter of the root system in response to salt stress was between 0%and 100%.Three species with higher salt tolerance were L.perenne,F.arundinacea,and F.sinensis.Amongst the L.perenne varieties,γ,Gentry,and Barlennium showed higher salt tolerance,whereas among Festuca spp.,the cultivars Fire Phoenix2,BarvadoⅡ,and Naihan showed higher salt tolerance.Similarly,among Trifolium spp.,cultivars with salt tolerance were Super-Huia in T.repens,Dolly in T.pratense,and Cherry in T.incarnatum.Furthermore,among Poa pratensis varieties,those with a higher salt tolerance were Merit,Baron,and Blue Chip,whereas among Agrostis spp.,the cultivars A-1,Kromi BT,Impala,and Highland all had higher salt tolerance.