水淹及盐胁迫对海滨锦葵生长及Na^+、K^+离子积累的影响

Effects of waterlogging and salt stress on growth and accumulation of Na^+ and K^+ in Kosteletzkya virginica

以具有3—4枚真叶的海滨锦葵小苗为处理材料,在可控温室下研究了海滨锦葵苗期生长、生物量积累与分配和植株Na+、K+离子积累对盐、水淹和水盐协同胁迫的响应。研究结果表明,盐胁迫处理对海滨锦葵株高、叶片数、主根粗、根系长及根系体积的抑制作用要明显于水淹胁迫处理(P<0.05)。水盐协同胁迫对株高、叶片数、根系体积和比叶面积的影响与盐处理没有显著差别(P>0.05)。盐和水盐协同胁迫显著降低了植株的相对含水量。水淹胁迫处理和对照相比没有显著影响根、茎和叶的生物量积累。同样,盐胁迫处理和水盐协同胁迫对根、茎、叶生物量的影响也没有显著差别,但都低于水淹处理和对照。各处理间对叶重比、茎重比、根重比和根冠比没有明显影响。水淹胁迫处理显著提高了植株的K+/Na+比,盐和水盐协同胁迫处理则显著降低了K+/Na+比。结果表明,海滨锦葵对水淹胁迫(与盐胁迫相比)有更强的适应能力。海滨锦葵通过稳定比叶面积、保持平衡的含水量、有效的生物量积累、均衡的生物量分配策略、K+促进吸收和保持高含量的K+/Na+比来提高对水胁迫的适应。

Seedlings of Kosteletzkya virginica at 3-4 leaf age were treated with waterlogging, salt stress and their combination in artificial climate growth chambers. Interaction between waterlogging and salt stress was analyzed in relation to plant growth, water status and ion contents （Na and K）. Results showed that stem and root length （SL, RL）, leaf number （LN）, taproot diameter （TD） and root volume （RV） were significantly inhibited by salt stress （p〈0.05） rather than by waterlogging. The combined treatment did not significantly affect SL, LN, root volume （RV） or specific leaf area （SLA） when compared to salt stress alone （p〉0.05）. The relative water content （RWC） was significantly decreased by salt stress and the combined treatment while no such an effect was observed under waterlogging. Lower values of leaf, stem and root dry weight （DW） were recorded in response to salt stress and the combined treatment （p〈0.05） when compared to waterlogging or control conditions while no changes in DW were observed in waterlogging alone. No difference was demonstrated in leaf weight ratio （LWR）, stem weight ratio （SWR）, root weight ratio （RWR） or root/shoot ratio among all treatments. However, the K＋/Na＋ ratio increased signifycantly under waterlogging while decreased significantly under salt and water-salt stress. It is concluded that K. virginica exhibits better adaptation to waterlogging than to salt stress through the maintenance of SLA, the rebalance of RWC, the validity of biomass accumulation and partitioning as well as the enhanced K＋ uptake and K＋/Na＋ ratio.