盐胁迫下不同小麦品种的耐盐性及其离子特征

SALT-RESISTANCE AND IONIC CHARACTERISTICS OF THREE WHEAT VARIETIES UNDER SALT STRESS

用盆栽试验方法研究了盐胁迫环境中三种小麦品种的生长速率与耐盐性差异。结果表明，盐度处理对小麦品种“德系j86－33－25”和“鲁麦10号”植株生长速率的影响低于对“科26”品种的影响，前两个品种较“科26”品种更为耐盐。本文还着重对盐胁迫条件下不同小麦品种植株组织中钾钠含量、钾／钠比、钾-钠吸收和运输的选择性、钠的吸收和运输速率及钠在植株体内的分布进行了分析，从而揭示了“德系j86－33－25”和“鲁麦10号”品种的抗盐机制可能与其根系抑制钠向地上部的运输并维持茎叶适宜的钾／钠比值有关。

Three wheat (Triticum aestivum) varieties, Dexi j86-33-25',' Ke 26' and' Lumai No. 10', were exposed to different concentrations of NaCl-Na2SO4 (0-50-150mmol / L)in a controlled pot culture system for 40 days, Fresh weightS of roots, dry weights and the sodium and potassium contents of stems, leaves and roots were measured to determine growth rates of wheat plants, K/ Na ratios, Na uptake rates, Na transport rates and K-Na selectivity ratios (Sk,Na).Growth reduction by salt treatment was significantiy greater in 'Ke 26' than in'Dexi j86-33-25'and' Lumai No. 10'. 'Dexi j86-33-25' and 'Lumai No. 10' showed a higher salt-resistance than 'Ke 26'. 'Dexi j86-33-25' and 'Lumai No. 10' had a higher potassium content but a lower sodium content in stems and leaves than 'Ke 26' under salt stress. So 'Dexi j86-33-25' and 'Lumai No. 10' had a higher K / Na ratio in stems and leaves than 'Ke 26' under salt stress. 'Dexi j86-33-25', 'Lumai No. 10' and 'Ke 26' had a similar Na uptake rate in the control treatment but the Na uptak rate,especially Na transport rate of three wheat varieties varied greatly with salt levels in media. 'Ke 26' had a higher Na uptake rate and Na transport rate than 'Dexi j86-33-25' and 'Lumai No. 10'. Furthermore, 'Dexi j86-33-25' and 'Lumai No. 10' exhibited a higher K-Na selectivity than 'Ke 26' at both whole plant level and shoot system level. Resistance mechanism of 'Dexi j86-33-25' and 'Lumai No. 10' was probably related to Na exclusion by roots and to the ability to maintain an appropriate K/ Na ratio in stems and leaves.