霍孝平 杜春梅 董锡文 李玉婷 韩笑 王文宣

摘要 [目的]从北方寒地种植的农作物根系土壤中分离遗传性能稳定、安全可靠、亲和性好、高效解无机磷的真菌，为微生物磷肥的开发提供适于该地区优良菌种。[方法]从北方寒地种植的农作物水稻、玉米和大豆根系土壤中分离解无机磷的真菌，对其进行鉴定及解无机磷能力的测定。[结果]通过PVK平板初筛和NBRIP平板复筛法，从种植大豆和玉米的根系土壤分离得到2株解无机磷真菌。显微观察初步鉴定为青霉属真菌。溶磷指数（SI）为2.65～2.80。采用钼锑抗比色法对发酵液进行解无机磷能力测定，在试验条件下青霉菌1和2发酵上清液中可溶性磷含量分别高达281.46和238.67 μg/mL。[结论]该试验得到2株解无机磷的青霉菌有望应用于生物磷肥的开发、生物防治和盐碱地的改良。

关键词 黑土;青霉菌;分离鉴定;解磷能力;寒地

中图分类号 X172 文献标识码 A

文章编号 0517-6611（2021）17-0001-04

doi：10.3969/j.issn.0517-6611.2021.17.001

Abstract [Objective]To isolate fungi with stable genetic properties，safety and reliability，good compatibility，and high efficiency in dissolving inorganic phosphorus from the root soil of crops grown in the northern cold regions，and to provide excellent strains suitable for the development of microbial phosphate fertilizers in this area.[Method]The fungi that dissolve inorganic phosphorus were separated from the root soils of crops of rice，corn and soybean grown in the northern cold regions，and the fungi were identified and the ability to dissolve inorganic phosphorus was determined.[Result]Two strains of inorganic phosphorus solubilizing fungi were isolated from the root soil of planting soybeans and corns by the methods of PVK plate primary screening and NBRIP plate secondary screening.Microscopic observation was preliminarily identified as Penicillium fungus.The phosphate index （SI） was 2.65-2.80.The molybdenum-antimony anti-colorimetric method was used to determine the ability of the fermentation broth to dissolve inorganic phosphorus.Under the test conditions，the soluble phosphorus content in the fermentation supernatant of Penicillium 1 and 2 was 281.46 and 238.67 μg/mL，respectively.[Conclusion]The experiment obtained 2 strains of Penicillium which can dissolve inorganic phosphorus and is expected to be used in the development of biological phosphate fertilizer，biological control and improvement of saline-alkali soil.

Key words Black soil;Penicillium;Isolation and identification;Phosphate-solubilizing;Cold region

磷是植物生長发育必需的主要营养元素之一，又是植物体内有机化合物的重要组成成分，参与光合作用、生物氧化、营养吸收和细胞分裂等重要代谢途径，对农作物的生长和产量具有直接影响[1-4]。土壤中通常含有1.32×10-2%～ 15.50×10-2% 磷和不溶性磷酸盐，占地球上总磷含量的95%～99%[5]，由于磷的溶解度低、化学固定和复合螯合作用造成磷的迁移率低，不能直接供植物或微生物利用[6]。在我国，土壤中约95% 的磷是顽固性磷，传统上通过添加磷肥来克服。然而，重复而不当地施用化学磷肥其成本是昂贵的，并可通过干扰微生物多样性和降低作物产量而导致土壤肥力的丧失[7]。……