Diversity and Pathogenicity of Six Diaporthe Species from Juglans regia in China.

Walnut (Juglans regia L.) is cultivated extensively in China for its substantial economic potential as a woody oil species. However, many diseases caused by Diaporthe greatly affect the health of Juglans regia trees. The present study revealed the presence of Diaporthe species from Juglans regia. A total of six species of Diaporthe were isolated from twigs of Juglans regia in three provinces in China, including two known species (Diaporthe gammata and D. tibetensis) and four novel species (D. chaotianensis, D. olivacea, D. shangluoensis and D. shangrilaensis). Phylogenetic relationships of the new species were determined by multilocus phylogenetic analyses based on partial sequences of the internal transcribed spacer (ITS) region, calmodulin (cal) gene, histone H3 (his3) gene, translation elongation factor 1-α (tef1-α) gene and ß-tubulin (tub2) gene. Pathogenicity tests indicated that all Diaporthe species obtained in this study were confirmed as pathogens of Juglans regia. This study deepens the understanding of species associated with several disease symptoms in Juglans regia and provides useful information for effective disease control.

Updating the Species Diversity of Pestalotioid Fungi: Four New Species of Neopestalotiopsis and Pestalotiopsis.

Pestalotioid fungi are associated with a wide variety of plants around the world as pathogens, endophytes, and saprobes. In this study, diseased leaves and branches of plants were collected from Guizhou and Sichuan in China. Here, the fungal isolates were identified based on a phylogenetic analysis of the internal transcribed spacer region (ITS), the translation elongation factor 1-alpha (tef1-α) and the beta-tubulin (tub2) of ribosomal DNA, and the morphological characteristics. Ten Neopestalotiopsis isolates and two Pestalotiopsis isolates were obtained, and these isolates were further confirmed as four novel species (N. acericola, N. cercidicola, N. phoenicis, and P. guiyangensis) and one known species, N. concentrica.

Multigene phylogeny and morphology reveal three new species of Cytospora isolated from diseased plant branches in Fengtai District, Beijing, China.

Members of Cytospora include saprobes, endophytes and important plant pathogens, which are widely distributed on various wood hosts and have a wide global distribution. In this study, the species definitions were conducted, based on multigene phylogeny (ITS, act, rpb2, tef1-α and tub2 genes) and comparisons of morphological characters. A total of 22 representative isolates obtained from 21 specimens in Fengtai District of Beijing City were identified as seven species of Cytospora, including four known species (C.albodisca, C.ailanthicola, C.euonymina, C.haidianensis) and three novel species (C.fengtaiensis, C.pinea, C.sorbariae). The results provide an understanding of the taxonomy of Cytospora species associated with canker and dieback diseases in Fengtai District, Beijing, China.