Abstract The ability of a plant to maintain low Na concentration is a critical component for its tolerance to salt affected soil stresses. Leaf Na concentration was investigated to understand its usefulness in screening of cotton for tolerance to soil sodicity and to assess its effect on agronomic performance. A set of family lines and high yield lines with low and high leaf Na concentration were tested in field experiments with sodic soils. The youngest fully expanded leaves at early flowering and whole plant biomass samples at the cut-out stage were collected for nutrient analysis. Plots were harvested for yield and fibre quality. Leaf Na concentration was found to be a reliable measure for differentiating test lines with low and high leaf Na trait. Leaf K/Na and P/Na ratio acted similarly. Low leaf Na concentration was due to higher Na accumulation in plant stems and roots. It was associated with higher K/Na and P/Na ratio in leaves and bolls, and responsible for improved K and P use efficiency. High performing lines with the low leaf Na trait had yield and fibre properties competitive with the control. It is concluded that the low leaf Na trait at flowering provided a reliable phenotypic indicator for cotton tolerance to soil sodicity. Breeding for the trait can improve sodicity tolerance, K and P use efficiency, while maintaining agronomic performance.

中文翻译：

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利用叶片钠浓度筛选棉花（Gossypium hirsutum L.）耐碱度

摘要 植物保持低 Na 浓度的能力是其耐受盐分影响的土壤胁迫的关键组成部分。研究了叶 Na 浓度以了解其在筛选棉花对土壤碱度的耐受性方面的有用性并评估其对农艺性能的影响。在含钠土壤的田间试验中测试了一组具有低和高叶 Na 浓度的家系和高产系。收集早期开花时最年轻的完全展开的叶子和切出阶段的全株生物量样品用于营养分析。收获地块的产量和纤维质量。发现叶 Na 浓度是区分具有低和高叶 Na 性状的测试品系的可靠措施。叶 K/Na 和 P/Na 比的作用类似。低叶 Na 浓度是由于植物茎和根中较高的 Na 积累。它与叶片和棉铃中较高的 K/Na 和 P/Na 比有关，并有助于提高 K 和 P 的利用效率。具有低叶 Na 性状的高性能品系具有与对照品相竞争的产量和纤维特性。得出的结论是，开花时的低叶钠性状为棉花对土壤碱度的耐受性提供了可靠的表型指标。育种该性状可以提高耐碱度、钾和磷的利用效率，同时保持农艺性能。得出的结论是，开花时的低叶钠性状为棉花对土壤碱度的耐受性提供了可靠的表型指标。育种该性状可以提高耐碱度、钾和磷的利用效率，同时保持农艺性能。得出的结论是，开花时的低叶钠性状为棉花对土壤碱度的耐受性提供了可靠的表型指标。育种该性状可以提高耐碱度、钾和磷的利用效率，同时保持农艺性能。