等渗透势干旱、盐、碱胁迫下枣和酸枣盐分离子吸收运输分配特性研究

摘要

Absorption, translocation and distribution characteristics of salt ions of two Chinese jujube cultivars and sour date plants under iso-osmotic potential (-0.30 MPa, -1.15 MPa) stresses of drought, salt and alkaline were invesigated. The results show that the differences of salt ion contents of the tested materials under these iso-osmotic stresses were significant, the content differences among different organs for same cultivar were also significant, but the influence to stem was the most light; changes of Cl" content was the smallest, but K+ and Na+ content significantly changed though changes of Jinsixiaozao, a resistant jujube cultivar, and sour date were smaller. Relatively, K+ content of leaves of the two jujube cultivars and sour date plants under all kinds of iso-osmotic stresses were of high stability and Na+ content increased small, meanwhile, both K+content decrease degree and increase degree of Na+ content of their roots were small. Under drought stress, Na+ contents of all the three tested materials were hardly affected, but the affaction to Cl" content was greater and its content in roots decreased while accumulated obviously in leaves. For Dongzao, a sensitive cultivar to drought, salt and alkaline stress, its responses of absorption, translocation and distribution to salt ions were rather different from those of Jingsixiaozao and sour date. Overall, the ion balance, especially K7Na+ ratio in plants under stresses and the absorption selectively, especialy translocation selectively to K+ and Na+ were clousely related to resistance of the three materials, and the part from shedding branch to leaf blade was the key part of their selective translocation to salt ions.`%以金丝小枣、冬枣和酸枣为试材,研究了两级等渗透势的干旱、盐、碱胁迫下盐分离子吸收、运输和分配特性.结果表明:等渗透势(-0.30 MPa,-1.15 MPa)的干旱、盐、碱胁迫下,金丝小枣(耐盐性强)、冬枣(耐盐性弱)及砧木酸枣体内盐分离子含量差异大,不同器官间含盐量差异也大；渗透势和胁迫种类对3种试材器官中盐分离子含量影响大,但以茎所受影响最轻；体内Cl-含量变化最小,而K+、Na+含量变化显著.抗性强的枣品种金丝小枣以及砧木酸枣,叶中K+含量在等渗的各种胁迫下稳定性强、Na+含量增幅小,且胁迫特别是盐、碱胁迫下根中K+含量降低幅度和Na+含量升高幅度均较小.干旱胁迫下,参试植物体内的Na+含量基本不受影响,但对Cl-吸收分配影响较大,根中Cl-含量降低,而在叶中则表现出较明显的积累.综合抗性弱的冬枣,对3种盐分离子的吸收分配特性与抗性强的金丝小枣及酸枣有很大不同,明显表现出比较敏感的特性,易于受到胁迫影响.总体上,枣和酸枣在逆境下对K+、Na+选择性运输能力的差异尤其与它们的抗逆性密切相关,根系对K+、Na+选择性吸收能力的差异对它们耐盐碱性至关重要,而由脱落性枝到叶片则是抗性强的枣品种及酸枣植株地上部对K+、Na+选择性运输的一个关键部位,耐盐机制具多样性.