根际解钾菌的筛选及其对烟草钾素吸收的影响

为提高烟叶钾含量，减少化肥施用量，采用选择性培养基结合烟草凝集素的筛选方法从烟草根际筛选高效解钾菌株，并分别通过盆栽试验和田间试验评估菌株对促进烟草生长及钾素吸收的效果。共筛选获得6株烟草根际解钾菌株，其中假单胞菌(Pseudomonas sp.)LK26菌株具有较优良的促生长特性。盆栽试验表明LK26菌株可显著提高烟草叶片和根系重量，提高烟草根际土壤钾含量及烟叶钾含量。田间试验表明，与施加减钾肥20%、未接种菌液及施全肥、未接种菌液的烟草植株相比，接种LK26菌株的烟草植株其根际土壤钾含量分别提高27.71%和10.25%；其下叶、中叶和上叶钾含量分别提高17.80%和5.30%，40.59% 和24.48% 以及15.69% 和5.36%。该菌株是一株潜在的烟草用生物钾肥优良菌株，具有进一步研究和应用潜力。

Isolation of potassium-solubilizing rhizobacteria and the effects on potassium absorption of tobacco plants

To increase the potassium content in tobacco leaves and reduce the amount of chemical fertilizer applied, a screening method via selective medium combined with tobacco lectin was used to screen highly efficient potassium-solubilizing bacteria from tobacco rhizosphere, and the effects of one of the isolated strains on promoting tobacco growth and potassium absorption were evaluated through pot and field experiments. A total of 6 strains of potassium-solubilizing bacteria were obtained from tobacco rhizosphere, among which Pseudomonas sp. strain LK26 exhibited excellent plant growth-promoting traits. The pot experiment showed that LK26 strain could significantly increase the weight of tobacco leaves and roots, and increase the potassium content in tobacco rhizosphere soil and tobacco leaves. The field experiment showed that compared with uninoculated tobacco plants with 20% reduced potash fertilizer and uninoculated tobacco plants with unreduced potash fertilizer, those inoculated with LK26 with 20% reduced potash fertilizer showed 27.71% and 10.25% higher the available potassium content in tobacco rhizosphere soil, respectively; and 17.80% and 5.30% higher potassium content in the lower leaves, 40.59% and 24.48% higher potassium content in the middle leaves, and 15.69% and 5.36% higher potassium content in the upper leaves, respectively. A potentially ideal biological potassium fertilizer-producing strain for use in tobacco production was developed. Strain LK26 has potential for further research and application.