低磷胁迫对番茄根系生长及根际土壤细菌多样性的影响

以低磷胁迫和平衡施肥处理的番茄根系及根际土壤为研究对象,采用Win RHIZO根系分析系统、稀释平板法、PCR-DGGE等分析技术,研究低磷胁迫对番茄根系生长、根际土壤生物学特性以及细菌多样性的影响。结果表明:低磷胁迫导致番茄根系总根长、总根表面积、总根体积和根尖数减少;导致根际土壤中可培养微生物(细菌、真菌和放线菌)数量、酶活性、微生物生物量(C、N、P)以及细菌的多样性指数(H)、丰富度(S)和均匀度指数(Eh)等表征土壤肥力及健康状态的指标下降;导致部分诸如甲基杆菌属(Methylobacterium sp.)等具有溶磷功能的菌群缺失;平衡施肥对番茄的正常生长和提升土壤肥力以及维护土壤健康具有极其重要的作用。

Effect of Low Phosphorus Stress on Root Growth and Soil Bacterial Diversity in Rhizosphere of Tomatoes

Based on the traditional and modern analyzed techniques，such as WinRHIZO root analysis system，dilution-plate method，PCR-DGGE etc.，the effect of low phosphorus stress on root growth，soil microbial properties and bacterial diversity under low phosphorus stress were analyzed. The results showed that the root length，surface area，volume and tip number were all decreased under low phosphorus stress. Additionally，soil microbial biomass，enzyme activities，microbial biomass（C，N，P）and soil bacterial diversity index（H），richness（S）and evenness index（Eh）were all also decreased under low phosphorus stress. However，some bacteria groups，such as Methyl bacterium（sp.），which have the function of soluble phosphorus，disappear in rhizosphere soil under low phosphorus stress condition. Moreover，it indicated that the degradation of soil fertility and soil bacterial community structure in rhizosphere were the main reason for the poor growth of tomatoes. The balance fertilization has an important function in improving the growth of tomatoes，soil fertility and health.