基于非培养和培养的方法比较花生根瘤菌遗传多样性

Genetic diversity of peanut bradyrhizobia estimated by culture-independent vs. culture-dependent approaches

摘要:

摘要:【目的】比较非培养和培养方法揭示的花生根瘤菌遗传多样性差异，以期建立慢生根瘤菌快速检测占瘤率技术。【方法】采用经典分离培养技术获得花生根瘤菌和非培养方法直接从根瘤中收获类菌体分别提取DNA后，比较分析BOX-PCR指纹图谱，根据多样性指数评价基于非培养和培养方法的BOX-PCR指纹图谱技术揭示花生根瘤菌遗传多样性的差异。【结果】基于非培养方法检测的花生根瘤类菌体为81.8%，获得85种遗传群;基于培养方法分离花生根瘤菌菌株为72.7%，获得71种遗传群;两种方法共同检测到17种 BOX-PCR遗传图谱相一致。根据多样性指数基于非培养方法反映不同地区花生根瘤菌遗传多样性结果较一致，基于培养方法反映各地区的花生根瘤菌遗传多样性结果存在明显差异。【结论】基于非培养方法检测根瘤类菌体的遗传多样性，能够更快速、真实反映不同土壤花生根瘤中的优势遗传群，快速地统计根瘤菌菌株占瘤率;与培养方法相结合有利于获得花生根瘤菌竞争结瘤能力强的土著菌株，从而为筛选高效根瘤菌菌株奠定基础。

Abstract:

Abstract:［Objective］To develop a rapid technique for estimating the percentage of bradyrhizobial nodule occupancy，we comparaed the differences of genetic diversity of peanut bradyrhizobia with culture-independent and culture-dependent methods．［Methods］ We used the traditional media plate technique for isolation of peanut bradyrhizobia and directly collected the bacteroids from peanut nodules． The BOX-PCＲ fingerprintings were compared after amplification with the DNAs of peanut bradyrhizobial isolates by culture-dependent approach and bacteroids by culture-independent approach．［Results］The percentage of testing for peanut bacteroids was 81. 8% with culture-independent method，and 85 genotypes of BOX-PCR were obtained． The percentage of isolation for peanut bradyrhizobia strains was 72. 7% and 71 genotypes of BOX-PCR were produced． There were totally 17 corresponding BOX-PCＲ genotypes obtained by both methods．［Conclusion］The culture independent method for direct analysis of genetic diversity from bacteroids in nodules can much more rapidly and clearly find the dominant genetic groups in different soil samples and fast figure out the percent of the rhizobia nodule occupancy．