中文摘要：

【目的】确定放线菌JXJ-0136的分类地位,分析其溶解不溶性磷的能力,在作物根际土壤定殖的情况及对蔬菜种子萌发、幼苗生长和蔬菜产量的影响,评价该菌在研制微生物肥料方面的潜在应用价值。【方法】利用培养特征、形态学特征和16S rRNA基因序列系统发育分析,初步确定菌株JXJ-0136的分类学地位;以白菜和豇豆为指示植物,采用琼脂平板法,研究该菌对蔬菜种子萌发和幼苗生长的影响;采用田间栽培试验,研究菌株对作物生长和产量的影响,测定栽培前后土壤总磷的含量,分析该菌对作物利用土壤磷效率的影响,并对作物根际土壤微生物进行分离纯化,分析该菌在根际土壤中的定殖情况;采用液体纯培养方式,研究菌株对不溶性无机磷和有机磷的溶解效率,分析其解磷机理。【结果】放线菌JXJ-0136在6—45℃、pH 4.0—13.0和0—4%（w/v）的盐浓度下均能生长,其中最适生长温度、pH和盐浓度分别约为28℃、p H 8.0和1%（w/v）,在ISP2培养基上该菌气丝较发达,灰白色,孢子丝簇生,孢子长卵圆形;该菌16S rRNA基因序列与链霉菌Streptomyces violascens、S.somaliensis、S.hydrogenans、S.albidoflavus和S.daghestanicus的亲缘关系最近,相似性依次为97.98%、97.71%、97.30%、97.23%和97.03%,但在系统进化树上与这些菌聚在不同分支上;该菌培养液能够显著提高作物种子萌发率,促进幼苗生长,在0.2%—0.8%的剂量下,白菜种子萌发率、幼苗株高和根长分别比对照组增加3.55%—12.61%、13.91%—53.03%和7.37%—51.92%,豇豆种子萌发率、幼苗株高和根长分别比对照组增加4.71%—21.18%、3.60%—22.33%和2.37%—20.08%;田间栽培试验显示,该菌能够定殖于根际土壤,促进作物对土壤磷的利用,提高作物产量,当每穴施加5 m L该菌培养液,试验结束时,白菜和豇豆试验组的土壤总磷含量分别下降（23.56±2.65）%和（37.10±1.98）%,分别为对照组的（1.77±0

英文摘要：

【Objective】The objective of this study is to determine the taxonomic status of an actinomycete strain JXJ-0136, investigate its ability of dissolving insoluble phosphorus, the colonization in the rhizospheric soil of crops, and its influences on the seed germination, seedling growth and yield of vegetables, and to evaluate the application value of strain JXJ-0136 in developing microbial fertilizer.【Method】Taxonomic status of strain JXJ-0136 was determined on the basis of the cultural and morphological characteristics, and the phylogenetic analysis of 16 S rRNA gene sequence. Influences of strain JXJ-0136 on the seed germination and seedling growth were studied using agar plate. The field cultivation tests were carried out to investigate the influences of strain JXJ-0136 on the growth and yield of vegetables. The total contents of phosphorus in the soil before and after the field trial were measured to investigate the influence of strain JXJ-0136 on the utilization of phosphorus in the soil by crops. The colonization of strain JXJ-0136 in the rhizospheric soil of the plants was investigated by isolation of the microorganisms in rhizosphere soil. The efficiencies of strain JXJ-0136 to dissolve insoluble inorganic and organic phosphorus were investigated using liquid pure culture. The model vegetables of the study were Brassica chinensis and Vigna unguiculata. 【Result】 Growth of actinomycete strain JXJ-0136 was observed at 6-45℃, pH 4.0-13.0 and 0-4%（w/v） NaCl, with optimal growth at 28℃, pH 8.0 and 1%（w/v） NaCl. Strain JXJ-0136 developed well-branched aerial mycelia on ISP 2 medium. The aerial mycelia was off-white in color. Its spore chains were fascicular with elliptical spores. The 16 S rRNA gene sequence was closest to Streptomyces violascens, S. somaliensis, S. hydrogenans, S. albidoflavus and S. daghestanicus with the similarities of 97.98%, 97.71%, 97.30%, 97.23% and 97.03%, respectively. However, strain JXJ-0136 formed different clades on phylogenetic tree. The culture broth of strai