马铃薯连作土壤微生物特性与土传病原菌的相互关系

Interrelation between Soil Microbial Characters and Borne Pathogen of Potato Continuous Cropping

为了揭示连作马铃薯土壤微生物群体与土传病原菌的相互关系,采用盆栽试验,以裸地(CK)和轮作(R)为对照,研究了不同马铃薯连作年限条件下(马铃薯连作1 a(T1)、3 a(T3)和5 a(T5))土壤微生物种群结构、酶活性、微生物量碳氮和土传病原菌的变化。结果表明,与R处理相比,T1、T3、T5处理土壤细菌/微生物的比例逐渐下降,土壤真菌/微生物和放线菌/微生物的比例逐渐增加。与CK和R处理相比,随连作年限的增加细菌/真菌显著下降。马铃薯连作后镰刀菌数量呈上升趋势,T3和T5处理茄病镰刀菌和尖胞镰刀菌数量显著高于硫色镰刀菌。连作后土壤蔗糖酶和脲酶活性呈降低趋势,R处理与T5处理差异显著,土壤过氧化氢酶呈先下降后上升的趋势,土壤多酚氧化酶活性呈动态上升趋势。连作马铃薯微生物量C、N量比轮作显著降低,T1、T3和T5处理土壤微生物量碳/氮比显著高于R处理。土壤细菌、微生物量碳氮显著促进土壤蔗糖酶和脲酶活性,土壤真菌抑制微生物量氮、蔗糖酶和脲酶活性,显著促进镰刀菌,而镰刀菌抑制细菌、微生物量碳氮、蔗糖酶和脲酶活性,从而导致了病原菌数量增多,土壤微生物的生存环境恶化。

To explore the relationship between microbial community and soil borne pathogen in potato continu- ous cropping soil, bare soil （CK） and rotation （R） were used as the control, pot experiments were carried out to in- vestigate the change of soil microbial population structure, enzyme activity and microbial biomass carbon, micro- bial biomass nitrogen, and soil-borne pathogens in potato continuous cropping for 1 year （T1）, for 2 years （T2） and 3 years （T3）. The results showed that the proportion of bacteria/microorganism was gradually declined; the proportion of fungi/microorganism was gradually increased in the treatment of T1, T3 and T5, compared with the R treatment. Compared with the CK and R treatment, the ratio of bacteria/fungi was decreased significantly with the increasing length of continuous cropping. The number of fusarium showed an increase trend. The number of fusarium solani and Fusarium oxysorum was significantly higher than fusarium sulphureum in the treatment of T3 and T5. The activity of soil sucrase and urease showed decreasing trend in continuous cropping of potato, which had significant difference between the treatment of R and T5. Soil catalase activity showed a trend of de- cline after rising first, soil polyphenol oxidase activity was on the rise. The content of soil microbial biomass C and N were significantly higher than R treatment; SMBC/SMBN of T1, T3, and T5 treatments were significantly higher than R treatment. Bacteria SMBC and SMBN in soil significantly promoted the activity of invertase and urease. Fungi in the soil inhibited the activity of invertase, and urease, microbial biomass nitrogen promoted fu- sarium, while fusarium inhibited the activity of invertase, urease, microbial biomass carbon and nitrogen. So, long-term continuous cropping of potato will lead to the number of pathogen increase, and the microbial living en- vironment deteriorate.