Isolation and cluster analysis of endophytic fungi in Narcissus tazetta var. chinensis / 中草药

ABSTRACT

Objective: To isolate and purify endophytic fungi from the roots and stems of Narcissus tazetta var. chinensis, and to analyze the composition and diversity of endophytic fungi. Medthods Endophytic fungi were isolated from the bulb and root of N. tazetta var. chinensis by surface sterilization and streaking on plate. Then, the isolates were identified based on morphological characteristics and internal transcribed spacer-rDNA (ITS-rDNA) sequences analysis. Besides, Shannon-Wiener biodiversity (H) and evenness (E) were selected as two key indexes, and the composition and diversity of endophytic fungi were analyzed. Results: Eighteen strains of endophytic fungi were isolated, in which 16 strains were obtained from the root (88.89%), the other two strains were obtained from the bulb (11.11%). ITS-rDNA fragments from 14 samples were respectively amplified by PCR method with their genomic DNA as templates. The sequencing results showed that most of these DNA fragments were about 500 bp. In addition, according to sequence analysis and comparison with the data in GenBank by BLAST, four strains with the similarity of 95% to 99% were classified as Penicillium, three strains were classified as Aspergillus with the similarity of 99% to 100%, three strains were classified as Rhinocladiella with the similarity of 99%, and the other four strains were classified as Trichoderma, Alternaria, Gibberella, and Fusarium, respectively, with the similarities about 99%. Therefore, it was concluded that Penicillium was the dominant endophytic fungi genus in N. tazetta var. chinensis under our experimental conditions. The phylogenic tree showed that these 14 endophytic fungi were clustered into two main branches, by which factors H and E were determined as 1.778 and 0.9137, respectively. Conclusion: The composition of endophytic fungi community has a certain diversity and difference.