低磷胁迫对桉树磷吸收与利用效率的影响

Effect on P Absorption and Use Efficiency of Eucalyptus spp. under Low Phosphorus Stress

采用盆栽法进行室内模拟低磷胁迫试验,对尾赤桉、巨桉、尾巨桉、邓恩桉等7个桉树品种在不同供磷水平下的各器官磷吸收与利用效率的比较分析。结果表明:尾巨桉、邓恩桉在正常供磷处理中的全株磷吸收效率较高,但在重度胁迫处理中较低;而尾赤桉、巨赤桉全株在重度胁迫条件下仍能保持较高的吸收效率,分别为66.10 mg·g-1、55.12 mg·g-1。随胁迫程度加重,各品种的全株磷利用效率呈递增趋势,但增幅不同。重度胁迫下,尾巨桉的全株磷利用效率较高(4.66 g·mg-1),其它6个品种间差异未达显著水平。初步筛选出尾巨桉为南方红壤区适宜栽植品种。

Objected with seven species of Eucalyptus,the indoor culture experiment with four phosphorus （ P） supplying levels was carried out.Through determining the P use and absorption efficiency of different organs in each eucalyptus specie,main results were as following.In the treatment with normal P supplying,both E.urophylla ×E.grandis and E.dunnii maintained high P use efficiency, but not in the treatment with no P.While E.urophylla ×E.camaldulensis and E.grandis ×E.camaldulensis could maintain a high level of P absorption efficiency under severe P deficiency stress,with 66.10 mg· g-1 and 55.12 mg· g-1 ,respectively.With low P stress level higher and higher, the P use efficiency of whole plant of all the species showed an increasing trend, which of E.urophylla ×E.grandis was 4.66 g· mg-1 when the level became severe P deficiency stress.In this treatment,there was no signifi-cant difference among other six species.We screened preliminary E.urophylla ×E.grandis as the elite species to plant in the red soil region in southern China.