节水灌溉对水稻抗逆生理性状的影响

研究目的]研究节水灌溉对水稻抗逆生理形状的影响,为水稻生产找到适宜的节水灌水指标.方法]通过防雨篷池栽试验,以土水势为灌水下限控制指标,重点研究了不同节水灌溉条件下水稻结实期时丙二醛(MDA)含量、细胞质膜透性、渗透调节物质等生理形状指标相对值变化规律.结果]研究结果表明,在适宜土壤水分胁迫下,即土水势高于-30 kPa,丙二醛(MDA)含量、细胞质膜透性、可溶性糖含量和游离氨基酸含量相对值有所升高,当土壤水分低于灌溉下限复水至土壤饱和时,有所恢复,随着生育时期延长,变化趋势平稳,这说明叶片本身存在一定对干旱胁迫适应与调节能力.当水势低于-30kPa时,丙二醛(MDA)含量、细胞质膜透性、可溶性糖含量和游离氨基酸含量相对值显著升高,抗旱性强品种的丙二醛(MDA)含量、细胞质膜透性增加或升高幅度小,抗旱性强品种可溶性糖含量和游离氨基酸含量升高幅度大.花后16天,细胞质膜透性、可溶性糖含量和游离氨基酸含量相对值降低.结论]上述结果表明,当田间土壤水势低于-30 kPa时,上述物质含量将显著增加,将影响水稻的生长,表明在水稻生长后期,灌溉下限应不低于-30kPa.

Water-saving Irrigation on Stress-resistance Physiological Factors of Rice

In order to investigate the effects of water-saving irrigation on stress-resistance physiological factors of rice, the trough cultivation experiment with rain-proof shelter were carried out. The results followed that the relative values of MDA, plasmalemma permeability, soluble sugar and amino acid in leaves increased and then decreased after rewatering to saturated soil under optimal water stress when the soil water potential was higher than -30kPa. The change trend became stable with the advance of growth stage. When the soil water potential was below -30kPa, the relative values of MDA, plasmalemma permeability, soluble sugar and amino acid in leaves significantly increased, increases of MDA and plasmalemma permeability in better drought resistant cultivars were obvious less than those in weaker drought resistant ones, and increases of soluble sugar and amino acid in better drought resistant cultivars were obvious more than those in weaker drought resistant ones, and plasmalemma permeability, soluble sugar and amino acid decreased from16 days to 40days after anthesis. These results suggest that water stress can induce physiological and biochemical changes in rice and changes of MDA content, plasmalemma permeability and osmotic regulators are correlated significantly to drought resistance of rice varieties.