不同施氮处理对平邑甜茶根系构型的影响

以平邑甜茶(Malus hupehensisRehd.)实生苗为试材,在沙培条件下研究供氮变化对平邑甜茶幼苗根系生长的影响。结果表明:1 mmol/L NO3-处理的植株茎叶生物量及根系生物量均达到最高水平,分别比对照增加116.7%和38.5%;对侧根生长而言,侧根长度与侧根数量也在1 mmol/L NO3-处理时最高,分别比对照增加168.9%和100.9%;但超过1 mmol/L后随浓度升高持续下降;NH4+处理的以上各指标表现相同的趋势,但相同供氮浓度时,NH4+处理的低于NO3-处理。对主根而言,氮素供应能明显促进主根生长,但各浓度处理间差异不显著。采用肥料袋控缓释方法研究氮素对平邑甜茶根系生长的影响,结果显示局部供应NO3-与NH4+均能显著增加侧根密度。

Effects of Different Nitrogen Treatments on Root Architecture of Malus hupehensis Rehd.

Malus hupehensis Rehd.seedlings were used to study the effect of nitrogen treatments on root growth under sand culture condition.The results showed that shoot and root biomass both reached the highest level supplied with 1 mmol/L NO-3,which were 116.7%and 38.5% more than that of control respectively.Length and number of lateral root also reached the highest level supplied with 1 mmol/L NO-3,which were 168.9%and 100.9% higher than that of the control.But above four indices decreased when NO-3 concentration was higher than 1 mmol/L.Above four indices under NH 4 treatment condition showed the same trend as NO-3 treatment,but was lower than that of NO-3treatment when supplied with the same nitrogen concentration.Nitrogen treatments remarkably increased growth of primary root,but differences among different concentration treatments were not marked.Local supplied NO-3 and NH 4 could increase lateral root density under fertilizer being bag-controlled release condition.