碱胁迫对不同品种菊芋幼苗生物量分配和可溶性渗透物质含量的影响

 【目的】探讨菊芋幼苗耐碱性与生物量和可溶性渗透物质在不同器官分配积累的关系。【方法】采用营养液砂培试验，以2个耐碱程度不同的菊芋品种‘南芋8号’（Ht 1，耐碱）和‘南芋1号’（Ht 2，耐碱性较弱）为材料，设置0.0、12.5、25.0以及37.5 mmol?L-1Na2CO3溶液模拟碱胁迫，研究其幼苗不同器官生物量分配和可溶性渗透物质含量的变化。【结果】碱胁迫下，2种菊芋幼苗各器官生物量比、Na+含量、K+含量、可溶性糖以及脯氨酸含量存在较大差异。相比之下，Ht 1在低碱胁迫（12.5 mmol?L-1）时叶片保持了较高的K+含量，根系积累了较多的干物质；较高碱胁迫（25.0，37.5 mmol?L-1）时叶片和根系积累了较多的可溶性糖，根系保持了较高的K+含量和较低的Na+含量，而Ht 2根系Na+含量、各器官脯氨酸含量以及茎可溶性糖含量在所有设定碱浓度下均较高。【结论】菊芋幼苗品种间耐碱性差异与其不同器官生物量和可溶性渗透物质的分配积累有关。耐碱菊芋品种低碱胁迫时叶片保持了较高的K+含量，根系分配了较多的干物质，较高碱胁迫时叶片和根系保持了较高的可溶性糖含量，根系保持了较高的K+含量和较低的Na+含量，这可能是其耐碱性较强的重要原因之一。

Effects of Alkaline Stress on Biomass Allocation and the Contents of Soluble Osmoticum in Different Organs of Two Helianthus tuberosus L. Genotypes

【Objectives】The purpose of this paper is to probe into the relationships between the resistance of Helianthus tuberosus L. Seedlings to alkaline stress and the accumulations of biomass and soluble osmoticum in different organs.【Method】with sandy culture in greenhouse，two Helianthus tuberosus L. genotypes Nanyu 8(Ht 1, alkaline-tolerant) and Nanyu 1(Ht 2, lower alkaline-tolerant) were exposed to nutrient solution with Na2CO3 added(0,12.5,25.0,37.5mmol mmol?L-1), and the biomass and osmoticum in different organs were determined.【Result】under alkaline stress, there were considerable differences in the biomass accumulations, the contents of Na+, K+, soluble sugar and proline in different organs between two genotypes. compared with each other it can be see that, Ht 1presented higher K+ in leaf and biomass invested in root under lower alkaline stress(12.5mmolL-1), higher soluble sugar in leaf and root and also higher K+ but lower Na+ in root under higher alkaline stress(25,37.5mmolL-1), whereas Ht 2 presented higher Na+ in root, proline in all organs and soluble sugar in stem in all designed concentrations.【Conclusion】The results indicated that considerable variations in the amount of biomass and soluble osmoticum among plant organs were related to Helianthus tuberosus L. genotypes in response to alkaline stress; Ht 1 had higher K+ in leaf and biomass invested in root under lower alkaline stress, higher soluble sugar in leaf and root and also higher K+ but lower Na+ in root under higher alkaline stress, which may ascribe to its higher alkaline tolerance. The accumulation of proline may be a damaged response of Helianthus tuberosus L .to alkaline stress.