Gnomoniopsis chinensis (Gnomoniaceae, Diaporthales), a new fungus causing canker of Chinese chestnut in Hebei Province, China

Abstract

Chinese chestnut (Castanea mollissima) is an important crop tree species in China. However, branch canker and fruit rot are two kinds of severe diseases, which weaken the host and decrease chestnut production. During our investigations into chestnut diseases in China, several fungi have been confirmed as casual agents in previous studies, namely Aurantiosacculus castaneae, Cryphonectria neoparasitica, Cry. parasitica, Endothia chinensis and Gnomoniopsis daii. In this study, a new canker pathogen is introduced based on morphology, phylogeny and pathogenicity. Typical Gnomoniopsis canker sign of wide, orange tendrils emerging from hosts’ glaucous lenticels were obvious on the diseased trees in the field. Symptomatic branches or bark on stems from different chestnut plantations were sampled and isolated, then strains were identified by comparisons of DNA sequence data for the nuclear ribosomal internal transcribed spacer (ITS), partial translation elongation factor-1α (tef1) and β-tubulin (tub2) gene regions as well as morphological features. As a result, these strains appeared different from any known Gnomoniopsis species. Hence, we propose a novel species named Gnomoniopsis chinensis. Pathogenicity was further tested using the ex-type strain (CFCC 52286) and another strain (CFCC 52288) on both detached branches and 3-year-old chestnut seedlings. The inoculation results showed that Gnomoniopsis chinensis is mildly pathogenic to Chinese chestnut. However, further studies are required to confirm its pathogenicity to the other cultivated Castanea species in America, Europe and Japan.

Identification and Characterization of Leaf-Inhabiting Fungi from Castanea Plantations in China

“…Interestingly, similar symptoms on Castanea mollissima in China were caused by two different species. Gnomoniopsis chinese causes branch canker, and G. daii causes fruit rot [ 54 , 55 ]. In this study, we confirmed the Gnomoniopsis pathogen on leaves in China as G. daii based on the phylogenetic inference of ITS, tef1 and tub2 sequence data ( Figure A10 ), and exactly matched morphology.…”

Rapid diagnostics for Gnomoniopsis smithogilvyi (syn. Gnomoniopsis castaneae) in chestnut nuts: new challenges by using LAMP and real-time PCR methods

“…Conversely, G. smithogilvyi is considered the worldwide most important threat of chestnut fruits, present in Oceania, North America and Europe (EPPO Global database). In China, chestnut rot is caused by other species of Gnomoniopsis , G. chinensis and G. daii (Jiang et al 2020 ; Jiang and Tian 2019 ).…”

Morphological observation and protein expression of fertile and abortive ovules in Castanea mollissima

“…Chinese chestnut (Castanea mollissima Blume) is an important crop/tree species and known as a 'wood cereal-and-oil-yielding' species and an 'iron crop' in China (Jiang, Liang & Tian, 2020). Chestnut kernels are rich in carbohydrates and protein but do not contain gluten or cholesterol, which considered as a healthy food (Chang et al, 2020).…”