香蕉内生细菌分离、活性评价及数量分布

从香蕉健康植株的根、假茎、叶柄、叶片等组织中分离获得386份内生细菌分离物。通过体外活性评价筛选出对9种常见的植物病原真菌具有一定抗性的内生细菌分离物28份,占总分离物的7.25%,其中对香蕉枯萎病菌抑制率达到80%~100%的分离物有9份。初步测定结果表明,这些分离物的基础生物学特性的分类地位初步归属为不动杆菌属(Acinetobacter)、芽孢杆菌属(Bacillus)、短杆菌属(Brevibacterium)、产碱杆菌属(Alcaligenes)和伯克霍尔德菌属(Burkholderia)细菌。9份分离物与病原真菌菌丝体对峙培养镜检结果表明,供试的9种病原真菌菌丝体均出现不同程度的肿胀与断裂。内生细菌在香蕉植株体内的数量分布分析发现,内生细菌在根、假茎、叶柄、叶片等组织中的数量分布呈递减趋势。

Isolation, Bioactivity Evaluation and Quantity Distribution of Endophytic Bacteria in Banana

There were 386 isolates of endophytic bacteria obtained from the tissues of healthy banana, such as roots, pseudo-stems, petioles and leaves. Among them, 28 isolates were screened out and found to show an antagonistic ability against 9 common fungus pathogens tested. And, among the antagonistic isolates 9 isolates were observed to inhibit the growth of Fusarium oxysporium, a causal agent of banana wilt, and the inhibition rates were from 80 % to 100 %. According to the fundamental biological characteristics, the 9 endophytic bacteria belong to the genera, Acinetobacter, Bacillus, Brevibacterium, Alcaligenes and Burkholderia. The tests showed that the hyphae of pathogen had different degrees of tumefaction and rupture. The analysis of the quantity distribution of endophytic bacteria in banana demonstrated a decreasing trend in the tissues from roots, pseudostems, petioles, and leaves, respectively.