【摘要】 采用紫花风铃木和黄花风铃木开展相互嫁接和自接4种嫁接处理,0.5%的NaCl溶液21 d盐胁迫处理,对各嫁接组合进行耐盐性观测并分析它们在盐胁迫下的细胞膜完整性、渗透调节物质含量、抗氧化酶活性以及钠和钾离子相对含量的变化,探讨2种风铃木嫁接植株的耐盐性变化及其响应机制。结果表明:2种风铃木的相互嫁接组合都能提高耐盐性,但以耐盐性更强的紫花风铃木为砧木的嫁接植株耐盐性更强。在盐胁迫条件下,风铃木嫁接苗的生理生化响应揭示了砧穗互作在提高其耐盐性中的重要作用。作用机制包括保持叶片和根系的细胞膜完整性,降低丙二醛的积累,提高游离脯氨酸含量以及超氧化物歧化酶活性,并将过量钠离子截留在根系,同时促进钾离子向上运输到叶片从而维持嫁接植株体内的离子稳态。更多还原

【Abstract】 To explore the changes in salt tolerance and the response mechanisms of 2 grafted Handroanthus species, 4 types of grafting treatments were conducted using H. impetiginosus and H. chrysanthus, including reciprocal grafts and self-grafts(controls). Using 0.5% NaCl solution for salt stress, after 21 days of stress treatment,the salt tolerance of each grafted combination was observed and analyzed, and the changes in cell membrane integrity, content of osmotic adjustment substances, antioxidant enzyme activities, and the balance of sodium and potassium ions under salt stress were observed and analyzed. The results indicated that both forward and reverse grafting unions of 2 Handroanthus species enhanced salt tolerance, with significantly greater salt tolerance in grafted plants using the more salt-tolerant H. impetiginosus as the rootstock. Under salt stress conditions, the physiological and biochemical responses of grafted Handroanthus spp. revealed the important role of rootstockscion interaction in improving their salt tolerance. The salt-tolerant mechanisms involved maintaining the integrity of cell membranes in leaves and roots, reducing the accumulation of malondialdehyde, increasing the content of free proline and the activity of superoxide dismutase, intercepting excess sodium ions in the roots, and promoting the upward transport of potassium ions to the leaves, thereby maintaining the ionic homeostasis within the grafted plants.更多还原