• ISSN 1008-505X
  • CN 11-3996/S
靳军英, 张卫华, 黄建国*. 干旱对扁穗牛鞭草生长、营养及生理指标的影响[J]. 植物营养与肥料学报, 2011, 17(6): 1545-1550. DOI: 10.11674/zwyf.2011.1071
引用本文: 靳军英, 张卫华, 黄建国*. 干旱对扁穗牛鞭草生长、营养及生理指标的影响[J]. 植物营养与肥料学报, 2011, 17(6): 1545-1550. DOI: 10.11674/zwyf.2011.1071
JIN Jun-ying, ZHANG Wei-hua, HUANG Jian-guo*. Effects of Water Stress on growth, nutrition and physiological indices of Hemarthria compressa[J]. Journal of Plant Nutrition and Fertilizers, 2011, 17(6): 1545-1550. DOI: 10.11674/zwyf.2011.1071
Citation: JIN Jun-ying, ZHANG Wei-hua, HUANG Jian-guo*. Effects of Water Stress on growth, nutrition and physiological indices of Hemarthria compressa[J]. Journal of Plant Nutrition and Fertilizers, 2011, 17(6): 1545-1550. DOI: 10.11674/zwyf.2011.1071

干旱对扁穗牛鞭草生长、营养及生理指标的影响

Effects of Water Stress on growth, nutrition and physiological indices of Hemarthria compressa

  • 摘要: 西南地区干旱频繁,当地的主栽牧草扁穗牛鞭草经常遭受干旱危害。试验设置正常供水,轻度、中度和重度干旱4种处理,盆栽试验研究了干旱对牛鞭草生长、营养和生理指标的影响。结果表明:中度和重度干旱显著抑制地上部生长,生物量减少20%~34%,但对地下部无显著影响,致使根冠比提高,有益于增强抗旱性。干旱条件下,氮、磷、钾吸收量显著减少,可能与根系活力降低有关。干旱降低了地上部的养分积累量,但对地下部养分积累量无显著影响,说明干旱改变了植株体内的养分分布。值得注意的是,干旱显著提高了根系含钾量,最高增加了36%,这有益于提高根细胞渗透压,增强水分吸收能力。此外,干旱不同程度地降低了叶片相对含水量、叶绿素含量和根系活力,可能是造成光合速率降低、养分吸收减少、生物量降低的原因之一。在其它生长和生理指标未发生显著变化的情况下,脯氨酸含量增加了约1.7倍。可以认为脯氨酸的积累可视为植物对干旱,尤其是轻度干旱产生的一种保护性生化反应。

     

    Abstract: As one of artificial pasture in Southwest China, Hemarthria compressa often suffers from drought due to frequently occurred dry spells. A green house pot experiment was carried out to study the effects of drought on the growth, nutrition and physiological indices of Hemarthria compressa under light, middle and serious water stresses. The control was established with normal water supply. The results indicate that the aboveground growth is inhibited and the biomass is reduced by 20-34% under the middle and serious droughts compared to those of the control, while underground growth is not significantly affected. As a result, the ratios of root to shoot are increased which benefit to improve the drought resistance. The absorptions of N, P and K are decreased significantly under the water stresses, which are possibly related to the drop of the root activity. The accumulations of nutrients in the aboveground are significantly reduced under the water stresses; while those of the roots are not affected. These results indicate that the nutrient distributions in the plants are changed. Notably, the K contents of roots are significantly increased under droughts, with the highest value of 36% compared with the control. K plays an important role in improving osmotic pressure of root cells, and promotes the moisture absorption. Moreover, the relative water contents of leaves, chlorophyll contents and root activities are reduced at different scales. The reductions are one of possible reasons to decrease photosynthetic rate, absorption of nutrients and the yield of pasture. However, the proline content is increased 1.7 times compared with the control, which is higher than the decrease of other physiological indices. Hence, the accumulation of proline might be regarded as the protective biochemical reaction produced by the plant, especially under the light water stress.

     

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