Shen Hong, He Xinhua, Liu Yiqing, Chen Yi, Tang Jianming, Guo Tao
Chongqing Key Laboratory of Soil Multi-scale Interfacial Process, College of Resources and Environment, Southwest UniversityChongqing, China; Collaborative Innovation Center of Special Plant Industry, Chongqing University of Arts and SciencesChongqing, China; Centre of Excellence for Soil Biology, College of Resources and Environment, Southwest UniversityChongqing, China.
Centre of Excellence for Soil Biology, College of Resources and Environment, Southwest UniversityChongqing, China; School of Plant Biology, University of Western AustraliaCrawley, WA, Australia.
Front Microbiol. 2016 Jun 22;7:841. doi: 10.3389/fmicb.2016.00841. eCollection 2016.
Limited information is available if plant growth promoting bacteria (PGPB) can promote the growth of fruit crops through improvements in soil fertility. This study aimed to evaluate the capacity of PGPB, identified by phenotypic and 16S rRNA sequencing from a vegetable purple soil in Chongqing, China, to increase soil nitrogen (N), phosphorus (P), and potassium (K) availability and growth of kiwifruit (Actinidia chinensis). In doing so, three out of 17 bacterial isolates with a high capacity of N2-fixation (Bacillus amyloliquefaciens, XD-N-3), P-solubilization (B. pumilus, XD-P-1) or K-solubilization (B. circulans, XD-K-2) were mixed as a complex bacterial inoculant. A pot experiment then examined its effects of this complex inoculant on soil microflora, soil N2-fixation, P- and K-solubility and kiwifruit growth under four treatments. These treatments were (1) no-fertilizer and no-bacterial inoculant (Control), (2) no-bacterial inoculant and a full-rate of chemical NPK fertilizer (CF), (3) the complex inoculant (CI), and (4) a half-rate CF and full CI (1/2CF+CI). Results indicated that significantly greater growth of N2-fixing, P- and K-solubilizing bacteria among treatments ranked from greatest to least as under 1/2CF+CI ≈ CI > CF ≈ Control. Though generally without significant treatment differences in soil total N, P, or K, significantly greater soil available N, P, or K among treatments was, respectively, patterned as under 1/2CF+CI ≈ CI > CF ≈ Control, under 1/2CF+CI > CF > CI > Control or under 1/2CF+CI > CF ≈ CI > Control, indicating an improvement of soil fertility by this complex inoculant. In regards to plant growth, significantly greater total plant biomass and total N, P, and K accumulation among treatments were ranked as 1/2CF+CI ≈ CI > CF > Control. Additionally, significantly greater leaf polyphenol oxidase activity ranked as under CF > 1/2CF+CI ≈ Control ≈ CI, while leaf malondialdehyde contents as under Control > CI ≈ CF > 1/2CF+CI. In short, the applied complex inoculant is able to improve available soil N, P, and K and kiwifruit growth. These results demonstrate the potential of using a complex bacterial inoculant for promoting soil fertility and plant growth.
关于植物促生细菌（PGPB）能否通过改善土壤肥力来促进果树作物生长的信息有限。本研究旨在评估从中国重庆的一种蔬菜紫色土壤中通过表型和16S rRNA测序鉴定出的PGPB增加土壤氮（N）、磷（P）和钾（K）有效性以及猕猴桃（中华猕猴桃）生长的能力。在此过程中，将17株具有高固氮能力（解淀粉芽孢杆菌，XD-N-3）、解磷能力（短小芽孢杆菌，XD-P-1）或解钾能力（环状芽孢杆菌，XD-K-2）的细菌分离株中的三株混合作为复合细菌接种剂。随后进行盆栽试验，研究这种复合接种剂在四种处理下对土壤微生物群落、土壤固氮、磷和钾溶解性以及猕猴桃生长的影响。这些处理分别为：（1）不施肥且不接种细菌（对照），（2）不接种细菌且施用全量化学氮磷钾肥料（CF），（3）复合接种剂（CI），（4）半量CF和全量CI（1/2CF+CI）。结果表明，各处理中固氮、解磷和解钾细菌的生长显著增加，从大到小依次为1/2CF+CI≈CI>CF≈对照。虽然各处理土壤全氮、全磷或全钾一般无显著差异，但各处理中土壤有效氮、有效磷或有效钾显著增加，分别呈现为1/2CF+CI≈CI>CF≈对照、1/2CF+CI>CF>CI>对照或1/2CF+CI>CF≈CI>对照的模式，表明这种复合接种剂改善了土壤肥力。关于植物生长，各处理中植株总生物量以及总氮、磷和钾积累显著增加，排序为1/2CF+CI≈CI>CF>对照。此外，叶片多酚氧化酶活性显著增加，排序为CF>1/2CF+CI≈对照≈CI，而叶片丙二醛含量排序为对照>CI≈CF>1/2CF+CI。简而言之，施用的复合接种剂能够提高土壤有效氮、磷和钾以及猕猴桃的生长。这些结果证明了使用复合细菌接种剂促进土壤肥力和植物生长的潜力。
