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土壤资源有效性在空间分布上的差异会对植物的生长发育产生重要影响。该文选择马尾松(Pinus massoniana)二代育种亲本育成的5个全同胞家系(1、25、49、52、57)为材料,进行一个生长季的局部供氮苗木盆栽实验。实验在同质低磷和异质低磷两种低磷环境下分别设置4个供氮处理:均匀供氮(HHH)、表层和中间层供氮(HHL)、底层供氮(LLH)和底层半侧供氮(LLH/L),研究了模拟异质养分环境对马尾松不同家系苗木生长及根系发育的影响。结果表明:1)与同质低磷相比,异质低磷促进了马尾松的生长和根系发育,其根长和根表面积分别为同质低磷下的1.95倍和2.11倍。2)局部供氮对马尾松生长的影响受土壤磷素环境影响较大,与HHH相比,局部供氮(HHL、LLH和LLH/L)对同质低磷下苗木的株高、地径和干物质积累量有明显的促进作用,但在异质低磷下,仅LLH和LLH/L处理有利于苗木地上部分的生长,HHL处理反而有抑制效应。3)在两种低磷环境下,LLH/L和LLH处理对马尾松苗木根系生长发育的促进作用显著,尤其在异质低磷环境下的促进作用较强(LLH/L处理下根长和根表面积较HHH处理高出29.2%和32.3%),但HHL对根长和根表面积有一定的抑制作用。4)马尾松不同家系间对不同供氮处理的响应差异显著。家系49、52和57主要通过增加根系在土壤中的分布来响应局部氮素分布的变化,促进整株干物质量的积累;家系25地上部分的生长随氮、磷含量的增大而增加,但根系的增生发育对其整株生长的贡献较小;家系1生长发育迟缓,对局部供氮的响应较为迟钝。研究结果显示,局部供氮较均匀供氮更有利于马尾松苗木生长,且土壤深层施肥的促进作用更强。
Differences in the spatial distribution of soil resource availability have a major impact on plant growth and development. In this study, five full-sib families (1,25,49,52,57) from second-generation breeding parents of Pinus massoniana were selected as materials to conduct a pot experiment of local nitrogen supply in one growing season. Four treatments of nitrogen supply were set up under low phosphorus and low phosphorus, respectively: uniform nitrogen supply (HHH), surface and intermediate supply of nitrogen (HHL), bottom supply of nitrogen (LLH) and bottom layer (LLH / L) were used to study the effects of simulated heterogeneous nutrient environments on seedling growth and root development in different Pinus massoniana families. The results showed that: 1) Compared with homogeneous low P, heterogeneous low P promoted the growth and root development of Pinus massoniana, and its root length and root surface area were 1.95 times and 2.11 times higher than that of the same quality and low P, respectively. 2) The effect of local nitrogen supply on the growth of Pinus massoniana was more affected by the soil phosphorus environment. Compared with HHH, the local nitrogen supply (HHL, LLH and LLH / L) And dry matter accumulation. However, only LLH and LLH / L treatments were beneficial to the growth of seedling shoots under heterogeneous phosphorus deficiency, but HHL treatment had inhibitory effects. 3) LLH / L and LLH treatments significantly promoted root growth of Pinus massoniana seedlings under both low-phosphorus environments, especially in the heterogeneous low-phosphorus environment (root length and root length under LLH / L treatment Root surface area was 29.2% and 32.3% higher than that of HHH), but HHL could inhibit root length and root surface area. 4) The response of Pinus massoniana to different N treatments differed significantly among different families. Family 49, 52 and 57 responded to the change of local nitrogen distribution by increasing the distribution of root system in the soil, and promoted the accumulation of whole plant dry matter. The growth of above-ground part of family 25 increased with the increase of nitrogen and phosphorus content The growth and development of the root system contributed little to its whole plant growth. The growth and development of the family 1 was slow and the response to local nitrogen supply was relatively slow. The results showed that the local nitrogen supply was more conducive to the growth of Pinus massoniana seedlings than the uniform nitrogen supply, and the deeper fertilization promoted the soil.