南方冬季条件下根际促生菌与肥料配施对巨菌草迁移累积镉砷的影响

优良菌种是微生物肥料的基础,研究微生物肥料中低温适应型菌株在低温条件下的促生性,对于提高南方冬闲时植物修复重金属污染农田具有重要意义.通过形态观察及18S rRNA基因序列分析,对菌株进行了鉴定,在此基础上进行植物盆栽试验,分析了 3株不同根际促生菌单独施加及其与肥料(鸡粪+微量元素)配施对镉砷复合污染土壤中巨菌草迁移...

Effects of combined application of plant growth-promoting rhibacteria and fertilizers on accumulation of cadmium and arsenic in Pennisetum sinese under winter conditions in southern China

Excellent strains are the basis of microbial fertilizers. In order to improve the phytoremediation of soil heavy metal contaminated farmland, it is of great significance to study the growth-promoting ability of low-temperature-adapted strains in microbial fertilizers under low-temperature conditions during the winter slack in southern China. Strains were identified through morphological observation and 18S rRNA gene sequence analysis. On this basis, a pot experiment was carried out to study the effects of three different plant growth-promoting rhizobacteria (PGPR) applied alone or in combination with fertilizer(chicken manure + trace elements) on the migration and accumulation of cadmium (Cd) and arsenic (As) in pennisetum sinese in the soil contaminated with Cd and As. The preliminary identification results of the isolated strains showed that M1, M2, and M3 were Trichoderma yunnanense, Gongronella butleri, and Diaporthe vaccinii, respectively. The pure culture experiments showed that M1, M2, and M3 could grow under low temperature conditions in southern winter. The results of the pot experiment show that, compared with CK treatment, the biomass of the stems and leaves of pennisetum sinese treated with single application of strains or fertilizer, or combination application of strains and fertilizer increased by 14.12%~84.35%, 13.36%, 57.25%~143.13%, respectively. Among all treatments, the combined application of M3 and fertilizer resulted in the maximum biomass of stems and leaves of pennisetum sinese. Different treatments could affect the absorption and bioaccumulation of Cd and As in pennisetum sinese, but the effects on each part in various tissues of pennisetum sinese are different. When strains were applied alone, M3 resulted in the greatest accumulation of Cd and As in the stems and leaves in pennisetum sinese with increasing magnitudes of 145.83% and 64.03%, respectively. When strains are combined with fertilizers, the combined application of M3 and fertilizers showed the greatest accumulation of Cd and As in the stems and leaves in pennisetum sinese with increasing magnitudes of 94.17% and 142.45%, respectively. Overall, the results of this study indicated that three PGPR could effectively promoted the biomass of pennisetum sinese in southern winter. Among them, the strain M3 combined with fertilizer has good prospect of being developed as a microbial fertilizer for effective treatment of soil contaminated with Cd and As.