茄子连作与轮作土壤养分、酶活性及微生物群落结构差异分析

Difference analysis of soil nutrients, enzymatic activities and microbial community structure between eggplant continuous cropping and rotation

研究茄子连作与轮作土壤养分、酶活性及微生物群落结构的变化,为阐明连作障碍和轮作减轻病害的机制提供理论依据。结果表明:与轮作相比,连作(茄子-茄子-茄子-茄子)土壤有效磷、钙、镁含量显著降低;多酚氧化酶、脲酶、碱性蛋白酶活性降低;细菌分类单元数量减少,真菌增多,两者的多样性指数降低,优势度指数升高。不同作物轮作方式间也存在差异,水旱轮作(茄子-水稻-水稻-茄子)与旱地轮作[茄子-四季豆(上半年)+长瓜(下半年)-四季豆(上半年)+长瓜(下半年)-茄子]相比,水旱轮作土壤酸碱度、总磷、有效磷、交换性钙、镁、锰含量显著增加,而盐度和有效硼含量显著降低;过氧化物酶、酸性蛋白酶、中性蛋白酶活性显著降低,而过氧化氢酶、脲酶、碱性蛋白酶活性显著升高;细菌分类单元数量增加,真菌减少,多样性指数升高,优势度指数降低。综上表明,轮作较连作更有利于保持或提高土壤肥力和土地生产力,尤其以水旱轮作较佳,是山地茄子栽培中值得推广的一种种植方式。

Eggplant（Solanum melongena L.） is one of nutritious vegetables welcomed by consumers. However, the diseases occurred on eggplants, particularly soil-borne diseases became increasingly severe, which hampered sustainable development of eggplant production. Based on our investigation, eggplant rotation is able to reduce the occurrence of diseases significantly, but its mechanism has not been explained clearly.In this study, we collected soil samples from different fields cultivated by eggplant continuous cropping and rotation to analyze their nutrients, enzymatic activities and microbial community structure using high throughput sequencing technique.The results showed that the contents of available P, Ca, Mg and Mn decreased significantly, and the activities of polyphenol oxidase（PPO）, urease（UE）, alkaline protease（ALPT） decreased; the number of bacterial operational taxonomic units（OTUs） reduced but fungal OTUs increased, and the bacterial and fungal diversity indexes decreased and the dominance index increased in fields with four-year continuous cropping（eggplant-eggplant-eggplant-eggplant, EEEE）, as compared with different eggplant rotation fields. However, there were significant differences in the nutrients, enzymaticactivities and microbial community structure from different soil samples between the four-year eggplant rotation fields[eggplant-rice-rice-eggplant, ERRE or eggplant-green bean（the early half of the year）＋bottle gourd（the latter half of the year）-green bean（the early half of the year）＋bottle gourd（the latter half of the year）-eggplant, EGBE] as well. Compared with the EGBE, the p H and the contents of total P, available P, exchangeable Ca, Mg and Mn increased significantly, but the salinity and available boron（B） reduced significantly; the activities of peroxidase, acid protease, neutral protease decreased significantly but the catalase, UE and ALPT increased significantly; the number of bacterial OTUs increased significantly but fungal OTUs decreased; the bacterial and fungal diversity indexes increased and the dominance indexes decreased in ERRE.In sum, ERRE is a good and worthy way for rotation by comprehensively considering soil p H, salinity, nutrients,enzymatic activities and microbial community structure in this study. The above results lay a theoretical foundation for choosing suitable cultivation system of eggplants in mountain regions.