硅对不同抗性高羊茅耐盐性的影响

Effect of silicon supply on the salt tolerance of two tall fescue(Festuca arundinacea)varieties with different salt resistance levels

为研究不同盐生境下硅对不同抗盐品种高羊茅(抗性强的XD和抗性弱的K31)耐盐性的影响,采用盆栽试验研究了添加硅对不同盐生境下两个高羊茅品种形态指标和保护酶活性的影响。结果表明:两个高羊茅品种的株高、分蘖数、叶片数、叶长、叶宽、地上含水量和生物量均随盐浓度增加呈降低趋势,而SOD、CAT和POD活性呈先增加后降低趋势,其中盐浓度为150、100mmol·L^(-1)时XD和K31的保护酶活性分别达到峰值。添加硅显著增加了两个高羊茅品种的株高、分蘖数、叶片数、叶长、地上含水量、地上生物量、SOD、CAT和POD(P<0.05),但两个品种高羊茅对硅响应存在盐浓度分异,具体表现为:盐浓度≤50mmol·L^(-1)时添加硅显著增加了XD分蘖数和叶片数(P<0.05),而对K31无显著影响;盐浓度≤100mmol·L^(-1)时加硅显著增加了XD的株高、叶长、地上生物量、SOD和CAT活性,盐浓度为150、200mmol·L^(-1)时,加硅显著增加了K31的株高、叶长、地上生物量、SOD、POD和CAT活性(P<0.05);硅仅在盐浓度≥200mmol·L^(-1)时显著增加了K31的地上含水量(P<0.05),而对XD地上含水量在任何盐浓度下均无显著影响。说明添加硅能够增强高羊茅的耐盐性,而且增强程度因盐浓度和高羊茅品种存在分异,在较高盐渍化条件下,硅对抗盐性较弱品种耐盐性增强的幅度大于抗盐性较强品种,使得抗盐性较弱的高羊茅品种能够通过添加硅肥而适应盐浓度较高的盐渍化土壤,扩大其适应范围成为可能。

A study has been undertaken to explore the effect of silicon supply on the salt tolerance of two varieties of tall fescue(Festuca arundinacea),XD and K31.XD has stronger resistance to salinization than K31.A pot experiment was conducted to investigate the effect of silicon on the plants’morphological indexes and protective enzyme activities under different salinization conditions.The results showed that plant height,tillers,leaf number,leaf length,leaf width,the aboveground biomass and water content of K31 and XD presented a decreasing trend with increases in salinity.The activities of superoxide dismutase(SOD),peroxidase(POD)and catalase(CAT)firstly increased and then decreased with rising salinity.The activity of protective enzymes in XD and K31 peaked when salt concentrations were 150 and 100 mmol·L-1.Silicon supplies significantly increased the tillers,leaf numbers,leaf length,plant height,aboveground biomass and water content,as well as SOD,POD and CAT activities,but the response of the two kinds of tall fescue varied under different salt concentrations.Silicon supplies significantly increased the tillers and leaf numbers of XD when salinity was below or at 50 mmol·L-1,but they did not affect K31.However,the leaf length,plant height,aboveground biomass,SOD and CAT activities of XD significantly increased when salinity was below or at 100 mmol·L-1.Silicon supplies also significantly increased the leaf length,plant height and aboveground biomass,SOD,POD and CAT activities of K31 when salt concentration was 150 and 200 mmol·L-1.These results indicate that silicon supplies could enhance the salt resistance of both kinds of tall fescue and that the extent of enhancement varies with salt concentration and the degree of tall fescue resistance.Under higher salinization conditions,the improving effect of silicon supply on salt tolerance was stronger in tall fescue with weak salt tolerance.These results show that it is possible to expand the adaptive range of tall fescue by supplying silicon.