基于盐胁迫条件下施用氮钾肥对面包果养分吸收及渗透物质积累的影响

为探究不同氮钾配比影响盐胁迫下面包果生长的营养生理机制,以面包果Artocarpus altilis (Parkinson) Fosberg]为材料,研究不同氮钾配比对盐胁迫下面包果养分吸收及渗透物质的影响。结果表明：与阴性对照（N₀K₀+W）相比,单盐胁迫（N₀K₀+S）对面包果生长指标有一定抑制作用,对根系生长指标有一定促进作用,其中N₁K₁+S处理的面包果地下部干重较单盐胁迫处理呈增加趋势,根系生长指标呈下降趋势。所有盐胁迫处理均显著增加根茎叶中的Na⁺含量和Na⁺/K⁺。与阳性对照（N₀K₀+S）相比,N₁K₁+S处理显著增加根茎叶中K⁺含量,减少叶中Na⁺含量和Na⁺/K⁺。N₁K₂+S处理较N₁K₁+S处理显著减少根茎中的Na⁺含量,N₂K₂+S处理较N₂K₁+S处理显著增加根中的N、P、K⁺、Na⁺含量和Na⁺/K⁺,茎中的N和K⁺含量以及叶片中的Na⁺含量、Na⁺/K⁺和叶片可溶性糖含量。N₂K₁+S处理较N₁K₁+S处理显著减少根、茎中K⁺含量,增加叶片N、Na⁺含量和Na⁺/K⁺,降低叶片可溶性糖含量,增加脯氨酸含量。N₂K₂+S处理较N₁K₂+S处理显著增加根、茎、叶中的Na⁺含量和Na⁺/K⁺。综上所述,适量增施氮钾肥通过调节K⁺、Na⁺向各器官的运输缓解盐胁迫对面包果生长及养分吸收的抑制效应,可为盐碱地的面包果施肥提供参考。

Effect of Application of Nitrogen and Potassium Fertilizers on Nutrient Absorption and Osmotic Accumulation of Breadfruit [Artocarpus altilis (Parkinson) Fosberg] under Salt Stress

In order to explore the nutritional and physiological mechanism of nitrogen and potassium on the growth of breadfruit under salt stress, this experiment used breadfruit seedlings Artocarpus altilis (Parkinson) Fosberg] as the test materials to compare the effects of different nitrogen and potassium application on the nutrient absorption and osmotic substances of breadfruit seedlings. Compared with the negative control (N₀K₀+W), single salt stress (N₀K₀+S) had an inhibitory effect on breadfruit growth indices and a promotion effect on root growth indices. Among them, the root dry weight under N₁K₁+S treatment showed an increasing trend, and the root growth indices showed a decreasing trend compared with the single salt stress treatment. All salt stress treatments significantly increased the content of Na⁺ and Na⁺/K⁺ in roots, stems and leaves. Compared with the positive control (N₀K₀+S), N₁K₁+S treatment significantly increased the content of K⁺ in roots, stems and leaves, and decreased the content of Na⁺ and Na^+/K⁺ in leaves. Compared with N₁K₁+S, the treatment N₁K₂+S significantly reduced the content of Na⁺ in in roots and stems. N₂K₂+S treatment significantly increased the contents of N, P, K⁺, Na⁺ and Na⁺/K⁺ in roots, N and K⁺ in stems, and the contents of Na⁺, Na⁺/K⁺ and soluble sugar in leaves compared with N₂K₁+S treatment. N₂K₁+S treatment significantly decreased the content of K⁺ in roots and stems, increased the contents of N, Na⁺ and Na⁺/K⁺ in leaves, decreased the soluble sugar content in leaves, and increased proline content compared with N₁K₁+S treatment. N₂K₂+S treatment significantly increased the content of Na⁺ and Na⁺/K⁺ value in roots, stems and leaves compared with N₁K₂+S treatment. In summary, proper application of nitrogen and potassium fertilizer could alleviate the inhibitory effect of salt stress on the growth and nutrient absorption of breadfruit by regulating the transport of K⁺ and Na⁺ to organs. The results could be used as a reference for fertilization of breadfruit in saline soil.