Inoculating zinc solubilizing microorganisms (ZSMs) is considered as a promising strategy for increasing Zn phytoavailability in soils with low Zn availability. In present study, we screened six strains of ZSMs from rhizosphere of green manure crop, including three strains of fungi, Talaromyces purpureogenus, Talaromyces pinophilus, and Penicillium amestolkiae, and three strains of bacteria, Cellulosimicrobium funkei, Isptericola cucumis and Streptomyces canus. We conducted a pot experiment of Bok choy inoculated with different ZSMs to analyze the Zn content in shoots and roots, and compared the Zn solubilizing effect of ZSMs. The results showed that Zn content in the roots and leaves of Bok choy of treatments inoculated with ZSMs were increased by 15%-44% and 27%-62%, respectively, and that soil DTPA-Zn concentration were increased by 52%-359%. The treatment inoculated with P. amestolkiae had the best effect. ZSMs significantly enhanced root uptake of Zn and foliar Zn content through increa-sing DTPA-Zn by mobilizing soil Zn by transformation of moderately available Zn (Zn bounded with manganese oxide and Zn strongly bounded with organic matter) to available Zn (exchangeable fraction, Zn bounded with carbonate, and Zn bounded with loose organic matter). The screened Zn mobilizing fungi averagely enhanced soil Zn phytoavailability and leaf Zn content by 240% and 46%, showing superior mobilizing ability than screened bacteria. P. amestolkiae significantly increased Zn content of soil and plant, thus it could be a promising potential microorganism as biofotification agent.
在低锌土壤接种解锌微生物,被认为是一种活化土壤锌、促进植物生长和锌吸收的有效途径。本研究从绿肥作物根际土壤中分离、获得6株解锌微生物,包括3株真菌——产紫篮状菌、嗜松篮状菌、克米斯托克青霉菌和3株细菌——芬氏纤维微菌、黄瓜白蚁菌和暗灰链霉菌。通过盆栽试验测定接种解锌微生物后低锌石灰性土壤小白菜地上部和根系锌含量,比较解锌微生物的解锌效果。结果表明: 与对照相比,接种解锌微生物后,小白菜根系锌含量增加了15%～44%,叶片锌含量增加了27%～62%;土壤二乙烯三胺五乙酸浸提锌(DTPA-Zn)含量增加了52%～359%,其中接种克米斯托克青霉菌效果最好。解锌微生物通过将土壤的中等有效锌(铁锰氧化物结合态锌和强有机结合态锌)向有效锌(离子交换态、碳酸盐结合态和松有机结合态)转化,增加了土壤DTPA-Zn含量,进而增加了小白菜根系对锌的吸收,显著提高了小白菜叶片锌含量。接种解锌真菌土壤有效锌含量和小白菜锌含量平均分别提高240%和46%,比接种解锌细菌提升效果更好。本研究筛选出的解锌真菌克米斯托克青霉菌在增加土壤锌有效性和提高植物锌含量方面均表现优异,可作为研制土壤锌活化生物制剂材料。.
Keywords: soil zinc bioavailability; soil zinc fraction; zinc solubilizing microorganism.