盐碱胁迫对芸豆幼苗生长及根际土壤化学性质的影响

Effects of Saline-alkali Stress on Common Bean Seedling Growth and Rhizosphere Soil Chemical Properties

以耐盐碱芸豆品种‘HYD’和盐碱敏感型芸豆品种‘JW’为试验材料,采用盆栽方法,用Na2CO3、NaHCO3 2种碱性盐按照摩尔比1∶9进行混合模拟盐碱生境,按照混合后占土壤中的质量百分比0(T0)、0.1%(T1)、0.2%(T2)、0.3%(T3)、0.4%(T4)、0.5%(T5)、0.6%(T6)浓度设计7个梯度,探讨了不同盐碱浓度处理对芸豆幼苗生长和根际土壤化学性质的影响,以期为耐盐碱芸豆品种的筛选提供参考依据。结果表明:2个芸豆品种株高、茎粗和单株地上鲜干质量和地下鲜干质量与根长、根表面积、根体积均随盐碱浓度增高表现出先增高后降低的趋势,其中在T1处理下达到最高值,‘HYD’株高较对照增加7.33%,‘JW’根体积较对照增加36.05%,且‘HYD’较‘JW’对不同盐碱胁迫浓度的变化响应更为明显。土壤pH和电导率均随着盐碱浓度升高呈现逐渐升高的趋势,‘HYD’和‘JW’根际土壤有机质、碱解氮、速效磷、速效钾含量均呈现先增高后下降的趋势,其中T6处理下显著降低,‘HYD’速效磷含量较对照降低14.30%,‘JW’速效钾含量较对照显著降低17.98%,并且在各盐碱浓度处理下,‘HYD’均高于‘JW’,表现出对盐碱胁迫较强的适应能力。综合分析表明,芸豆幼苗根系通过对Na^(+)的积累与限制作用,土壤中矿质离子含量增加,提高植物对有效养分吸收以适应盐碱胁迫,故芸豆幼苗生长和根际土壤化学性质均呈现低浓度盐碱胁迫处理在一定程度上促进,高浓度盐碱胁迫处理表现为抑制。

Taking the saline-alkali-tolerant common bean variety ‘HYD’ and the saline-alkali-sensitive common bean variety ‘JW’ as test materials,potted plants were used.Two basic salts of Na2CO3 and NaHCO3 were mixed to simulate the saline-alkali habitat at a molar ratio of 1:9.According to the mass percentage in the soil after mixing,0%(T0),0.1%(T1),0.2%(T2),0.3%(T3),0.4%(T4),0.5%(T5),0.6%(T6) concentration seven gradients were designed to explore the effects of different saline-alkali concentration treatments on the growth of common bean seedlings and the chemical properties of rhizosphere soil.In order to provide a reference for the screening of salt-tolerant common bean varieties.The results showed that the plant height,stem thickness and freshness and dry weight of individual plant aboveground,root length,root surface area and root volume of the two common bean varieties showed a trend of first increasing and then decreasing with the increase of saline-alkali concentration.The highest value was reached under T1,the plant height of variety ‘HYD’ increased by 7.33% compared with the control,the root volume of variety ‘JW’ increased by 36.05% compared with the control,and the response of variety ‘HYD’ to changes of different saline-alkali stress concentrations was more obvious than that of ‘JW’.Both soil pH and electrical conductivity showed a gradual increase trend with the increase of saline-alkali concentration.The contents of rhizosphere soil organic matter,available nitrogen,available phosphorus and available potassium of ‘HYD’ and ‘JW’ all showed a trend of first increasing and then decreasing.Among them,it was significantly reduced under T6,the content of available phosphorus in variety ‘HYD’ was reduced by 14.30% compared with the control,and the content of available potassium in variety ‘JW’ was significantly reduced by 17.98% compared with the control.In addition,‘HYD’ varieties were higher than ‘JW’ under the treatments of various saline-alkali concentrations,showing strong adaptability to saline-alkali stress.Comprehensive analysis showed that through the accumulation and restriction of Na^(+),the roots of common bean seedlings increase the content of mineral ions in the soil and increase the absorption of effective nutrients by plants to adapt to saline-alkali stress.Therefore,the growth of common bean seedlings and the chemical properties of the rhizosphere soil both present low concentrations of salt.The alkali stress treatment promoted to a certain extent,and the high concentration saline alkali stress treatment showed inhibition.