对枯萎病不同抗性的香蕉品种的内生细菌多样性及群落结构

Endophytic bacterial diversity and communities of banana cultivars with different resistance to fusarium wilt disease

摘要:

【目的】了解抗感品种香蕉植株中内生细菌与香蕉枯萎病间的关系, 从而为香蕉枯萎病的发生与防控提供一定的理论基础。【方法】通过基于16S rRNA的末端标记限制性片段长度多态性技术(Terminal restriction fragment length polymorphism, T-RFLP)分析健康和感枯萎病香蕉植株不同品种各组织, 以及香蕉植株不同发病时间根组织中内生细菌的多样性和群落结构。【结果】抗病品种“农科一号”植株根、假茎、叶片各组织中内生细菌的种类基本都比感病品种“巴西蕉”的相应组织中的要丰富。感枯萎病香蕉植株根、假茎、叶片各组织中内生细菌种类基本都比健康植株各组织的丰富。在植株发病前、发病初期、再到发病后一个月的不同时期, 对于抗病品种而言, 其内生细菌的多样性都基本保持稳定, 而感病品种则变化幅度较大。同时发现不同品种不同组织的内生细菌的优势种群有所不同, 且不同品种健康和发病植株都存在一些特有优势种群。【结论】香蕉抗病品种比感病品种植株中内生细菌的多样性更丰富且更稳定; 感枯萎病植株中的内生细菌种类比健康的丰富; 而且不同抗性品种中健康和感病植株内的优势种群存在明显差异。

Abstract:

[Objective] In order to understand the relationship between endophytic bacterial diversity of banana and fusarium wilt disease, thus providing a scientific basis for the biological control against fusarium wilt. [Methods] Endophytic bacterial diversity and communities of different plant tissues of two banana cultivars with different resistance to fusarium wilt were examined using Terminal Restriction Fragment Length Polymorphism (T-RFLP). [Results] The results indicated that resistant cultivar “Nongke No.1” showed more abundant endophytic bacterial diversity than that of susceptible cultivar “Brazil” in the root, pseudomeristem and leaves of plants. Diseased plants conserved more abundant endophytic bacterial diversity than that of healthy plants in different tissues. Endophytic bacterial diversity of “Nongke No.1” kept basically stabilized, but that of “Brazil” showed a great range of variation among healthy and different diseased stages. Dominant bacterial populations were various in the different tissues, and there were some specific dominant populations in the healthy and diseased banana plants of different cultivars. [Conclusion] The results indicated that resistant cultivar showed more abundant and steady endophytic bacterial diversity than that of susceptible cultivar. Diseased plants showed more abundant endophytic bacterial diversity than healthy plants. In addition, there is a marked diversity of dominant populations in different plants between resistant or susceptible cultivars to fusarium wilt disease.