盐胁迫与供磷水平对柳枝稷苗期生理特性的影响

Effects of salt stress and phosphorus supply on physiological characteristics of switchgrass seedlings

为了明确不同柳枝稷品种对盐胁迫和供磷水平两个因素的生理响应特征,本研究采用水培试验,设置2个盐胁迫水平(A1盐胁迫、A2非盐胁迫)和4个供磷水平(B1无磷、B2低磷、B3高磷、B4全磷),分析了盐胁迫和供磷水平对Alamo加倍体、Alamo和Pathfinder 3个柳枝稷品种苗期生理特性的影响规律。结果表明:Alamo加倍体、Alamo和Pathfinder在盐胁迫条件下可溶性糖含量随着供磷水平的增加而降低,全磷处理下较无磷处理分别降低40.80%、26.47%、13.82%。盐胁迫下3个柳枝稷品种丙二醛含量随着供磷水平的提高均在高磷处理下达到最大值。3个柳枝稷品种在盐胁迫下脯氨酸含量随着供磷水平增加而增加,全磷处理较无磷处理分别升高288.16%、544.21%、330.49%。盐胁迫下Alamo加倍体和Alamo的过氧化物酶(POD)活性随着供磷水平的提高均在全磷处理下达到最大值;而Pathfinder的POD活性在低磷处理下达到最大值。盐胁迫下Alamo加倍体的超氧化物歧化酶(SOD)活性随着供磷水平提高在高磷处理下达到最大值;盐胁迫下Alamo和Pathfinder的SOD活性随着供磷水平的提高均在低磷处理下达到最大值。3个柳枝稷品种在盐胁迫条件下过氧化氢酶(CAT)活性随着供磷水平增加而降低,全磷处理较无磷处理显著降低65.81%、37.41%、90.66%。通过对3个柳枝稷品种综合生理抗逆性分析得出Pathfinder品种在各处理下综合值之和最高,表明Pathfinder苗期抗盐胁迫与低磷胁迫能力最强,适宜在盐碱地种植。

In order to clarify the physiological response characteristics of different switchgrass varieties to the two factors of salt stress and phosphorus supply level,this study adopted a hydroponic experiment with 2 salt stress levels(A1 salt stress,A2 non-salt stress)and 4 phosphorus supply levels(B1 no phosphorus,B2 low phosphorus,B3 high phosphorus,B4 full phosphorus)were set.The results showed that the soluble sugar content of Alamo syndiploid,Alamo and Pathfinder decreased with the increase of the phosphorus supply level under salt stress conditions,and the total phosphorus treatment decreased by 40.80%,26.47%,and 13.82%compared with the non-phosphorus treatment.The malondialdehyde(MDA)content of the three switchgrass varieties under salt stress reached the maximum under the high phosphorus treatment with the increase of the phosphorus supply level.The proline content of the three switchgrass varieties increased with the increase of the phosphorus supply level under salt stress,and the total phosphorus treatment increased by 288.16%,544.21%,330.49%respectively compared with the non-phosphorus treatment.Under salt stress,the peroxidase(POD)activity of Alamo syndiploid and Alamo reached the maximum under the full phosphorus treatment with the increase of the phosphorus supply level;while POD activity of Pathfinder reached the maximum under the low phosphorus treatment.The superoxide dismutase(SOD)activity of Alamo syndiploid under salt stress reached the maximum under high phosphorus treatment with the increase of phosphorus supply level;the SOD activity of Alamo and Pathfinder under salt stress reached the maximum under low phosphorus treatment with the increase of phosphorus supply level value.The catalase(CAT)activity of the three switchgrass varieties decreased with the increase of the phosphorus supply level under the salt stress condition.Compared with the non-phosphorus treatment,the CAT activity decreased by 65.81%,37.41%,and 90.66%.According to the comprehensive physiological stress resistance analysis of 3 switchgrass varieties,it was concluded that Pathfinder variety has the highest sum of comprehensive values under each treatment,indicating that Pathfinder has the strongest resistance to salt stress and low phosphorus stress at seedling stage and is suitable for planting in saline-alkali land.