Endophytic Diaporthe from Southeast China are genetically diverse based on multi-locus phylogeny analyses.

ABSTRACT

Species of Diaporthe (anamorph Phomopsis) comprise a diverse and widely distributed group of phytopathogens, saprophytes and endophytes. However, the degree of genetic diversity of endophytic Diaporthe has not yet been fully investigated. In this paper, a survey of endophytes from 28 plants in southeast China yielded 116 Diaporthe isolates, out of which 64 haplotypes were determined using DnaSP ver. 5.1 based on alignment result of internal transcribed spacer of ribosomal nucleotide sequences (ITS rDNA). Many haplotypes turned out to be quite different from known species and displayed high diversity. Among them, 14 strains from 5 discriminating terminal clades were selected to go through further analysis according to partial sequence of translation elongation factor 1-α (tef1-α) and again they got separated from others. The following multi-gene phylogenetic analysis based on ITS rDNA, tef1-α, ß tubulin and calmodulin grouped eight most discrepant strains into three distinctive clusters, cluster 1 (Rc001, Eu004 and Eu009), cluster 2 (ZJWCF252, Sjm001 and Ac001) and cluster 3 (Pcs013 and Sfp005) respectively with high support values. These clusters above represent three potentially novel species. This research provides strong evidence of high biodiversity and novelty of Diaporthe endophytes from southeast China, which is thus important not only for better resolving the taxonomy in this genus, but also for further utilization due to their multiple application.