摘要
试验设置正常浇水、轻度、中度和重度干旱4种处理,盆栽研究了牛鞭草干旱胁迫与复水的补偿效应,为其水分管理提供科学依据。结果表明,轻度干旱对牛鞭草生长无显著影响;恢复供水后第12天,牧草产量轻度干旱〉正常供水≈中度干旱〉重度干旱,轻度干旱的牧草产量比正常供水增加11.47%。在轻度和中度干旱条件下,牛鞭草含氮量显著高于正常供水,复水后第12天与正常供水相似。说明适度干旱后复水不影响甚至提高牛鞭草产量和蛋白质含量。在干旱条件下,牛鞭草根冠比增加,含钾量提高,脯氨酸积累;但硝酸还原酶和根系活力下降,磷、钾吸收量减少,中~重度干旱吸氮量降低。干旱后恢复供水,叶片相对含水量、脯氨酸含量和硝酸还原酶活性迅速恢复正常,叶绿素含量逐渐提高,根系活力在复水12d时高于正常供水。复水产生的这些生理补偿效应有益于氮素同化,养分吸收和光合作用,使植株恢复正常的新陈代谢和生长发育。在人工栽培牛鞭草的过程中,充分利用这种补偿效应可节约用水,减轻旱害,提高产量品质。
The aim of this study was to evaluate the effects of drought stress and compensatory rewatering on Hemarthria compressa, to provide a scientific basis for water management during the cultivation of this plant. Four treatments （normal water supply, light drought, medium drought, and heavy drought） were established in a pot experiment. Light drought did not significantly affect the growth of H. compressa. On day 12 after rewatering, the four treatments could be ranked, based on the biomass of plants, as follows： light drought〉normal water supply≈medium drought〉heavy drought. The biomass of plants under light drought was 11.47% greater than that of plants with a normal water supply. Also, the nitrogen content in H. compressa was significantly higher in plants under light and medium drought than in those with a normal water supply, and was similar in control plants and drought-stressed plants on day 12 after rewatering. These results showed that appropriate drought and rewatering barely affected or even improved the yield and protein content of H. compressa. Drought increased the root/shoot ratio and potassium and proline contents in H. compressa. However, medium and heavy drought led to decreases in nitrate reductase activity, root activity, and phosphorus, potassium, and nitrogen uptake. After rewatering of drought-stressed plants, the relative water content of leaves, proline content, and nitrate reductase activity recovered quickly to levels similar to those in the control, and the chlorophyll content increased gradually. The root activity of drought-treated plants on day 12 after rewatering was significantly higher than that in the control. The recovery of root activity was helpful for nitrogen assimilation, nutrition uptake, and photosynthesis, which restored normal metabolism and growth. These results implied that mild drought and rewatering could not only save water and mitigate drought damage, but also improve the yield and quality of cultivated H. compressa.
出处
《草业学报》
CSCD
北大核心
2016年第10期104-112,共9页
Acta Prataculturae Sinica
基金
西南大学博士资金项目(SWU112059)
国家水体污染控制与治理科技重大专项(2012ZX07104-003)资助
关键词
牛鞭草
干旱
复水
补偿效应
Hemarthria compressa
drought
rewatering
compensatory effect
