磷肥处理对烤烟生长生理及根系构型的影响

采用根箱栽培，研究了高 P、低P对烤烟生长生理及根系构型的影响，结果发现，烟株生长指标（株高、茎围、叶重、根重）、生理指标（烟叶净光合速率、硝酸还原酶活性、烟株根系活力）、根际土壤微生物数量（细菌、真菌、放线菌）均为高P处理大于低P处理。高P和低P处理烟株根系构型具有各自鲜明的发根特征和侧重点，高P处理根系构型优势在烟株发育后期的第三轮根以及一级侧根，而低P处理根系构型主要优势在第一轮根、第二轮根及总不定根。低P处理烟株不定根的生成量超过高P处理。

Effects of phosphorus treatment on flue-cured tobacco growth physiological characteristics and root configuration

The method of root box was adopted to cultivate flue-cured tobacco. Two fertilizer treatments of high phosphorus and low phosphorus were designed to investigate the effects of high phosphorus and low phosphorus on physiological characteristics, rhizosphere microbe quantity and root configuration of flue-cured tobacco. The results showed that tobacco growth index (plant height, stem width, leaf weight, root weight), physiological index (Pn, NAR, root activity), rhizosphere microbe quantity (bacteria, fungi, actinomyces) under high phosphorus treatment were all higher than low phosphorus treatment. Root configuration under high phosphorus treatment and low phosphorus treatment had their own distinct rooting traits and emphasis respectively, the superiority of root configuration under high phosphorus treatment occurred at the third round root and surface lateral root in late tobacco growth stage, but low phosphorus treatment occurred at the first round, the second round and total adventitious root. The amount of adventitious root under low phosphorus treatment was higher than high phosphorus treatment.