两株毒死蜱降解细菌菌株鉴定及对萝卜种子萌发的影响

Identification of Two Chlorpyrifos-degrading Strains and the Effect of Bacterial Fermentation on Seed Germination of Radish

鉴定两株有较强降解毒死蜱能力的菌株N16和N432,并初步探讨此两株细菌菌液对萝卜种子萌发的影响。通过对其形态、生理生化特征及16S rDNA的分析,进行初步鉴定;以不同浓度的菌液浸泡萝卜种,之后于25℃下培养,测定发芽势、发芽率、发芽指数、活力指数。通过形态特征及序列分析,这两株菌均为琼氏不动杆菌属(Acinetobacter junii)。N16细菌原液对萝卜种子发芽率、发芽指数均高于对照组,N432作用完全相反。菌株N16对萝卜种子的萌发具有促进作用,这种促进作用随着培养液的稀释,呈现逐渐降低的趋势。而菌株N432则对种子的萌发具有抑制作用,并且这种抑制作用随着培养液的稀释呈现减弱趋势。

Two bacterial strains N16,N432 which could degrade chlorpyrifos were identified,and the effect of the fermentation liquid from the strains on sprout and seeding of radish was studied.The strains were identified based on the morphological,physiological,biochemical characteristic and 16S rDNA sequences.The radish seed treated with the fermentation liquid at 25℃ were cultures,and then germination energy,germination rate,germination index,vigor index were measured.It is showed that N16,N432 were identified as Acinetobacter junii according to the morphological characteristic and sequencing.Germination energy,germination rate,germination index,vigor index of radish seeds pretreated with pure bacteria liquid of N16 were higher than control,but they were inhibited by the N432.Germination rate and germination index were promoted by the liquid culture of N16,but they were inhibited by the liquid culture of N432.And the effects including inhibition of N432 and enhancement of N16 would be weakened when their liquid cultures were diluted.