不同供铵水平对番茄根系生长的影响

Effects of Different Levels of NH_4^+ on Growth of Tomato Roots

植物根系对各种养分供应高度敏感。本文以番茄为研究材料,采用整株和根部琼脂培养方法,研究不同浓度NH4+对根系生长的影响。结果表明:当整体供NH4+浓度大于0.5mmol/L,主根长、侧根数和株高均随着NH4+的增加而变小,10 mmol/LNH4+几乎完全抑制了侧根形成。整体供NH4+对番茄生长的抑制效应大于相等浓度的NH4+仅供应于根部。而低浓度的NH4+(10~100μmol/L)供应于根部,在基本不影响主根长度的情况下,能显著增加侧根数量。依据所使用的NH4+浓度及不同的供NH4+方式,NH4+对番茄生长特别是侧根形成具有显著的抑制作用或促进效应。

The development of root system is extremely sensitive to the supplies of various nutrients, the effects of different levels of NH4＋ supplying on plant growth were studied in Solanum lycopersicum by using an agar-based whole-plant or root localized contact culture. The results showed that when the concentration of whole-plant supplied NH4＋ was higher than 0.5 retool/L, primary root length, lateral root numbers and plant height were decreased with further increase of the concentrations of NH4＋ in the agar, and the development of lateral roots was almost completely inhibited by 10 mmol/L NH4＋. Compared with the influence of corresponding NH4＋ supplied only to the roots, the inhibitory effect of NH4＋ on growth was greater when whole plant exposed to NH4＋. Lower concentrations of NH4＋ （10-100 μmol/L） supplied to the roots can significantly increase the lateral root numbers without evident influence on primary root length. Thus, depending on the concentration and distribution, NH4＋ has either negative or positive effects on the development and growth ofSolanum lycopersicum especially for the lateral roots.