Calonectria species isolated from Eucalyptus plantations and nurseries in South China

Abstract

Diseases caused by species of Calonectria (Ca.) represent a serious threat to the growth and sustainability of Eucalyptus plantations in China. Symptoms caused by these fungi mainly include leaf blight on trees in plantations and rotting of stems and leaves in nurseries. Extensive surveys have recently been conducted where Calonectria species were collected in Eucalyptus plantations and nurseries in the FuJian, GuangDong, GuangXi, and YunNan Provinces of South China. Additional isolates were baited from soil samples in the Hong Kong Region. The aim of this study was to identify the 115 Calonectria isolates obtained using comparisons of DNA sequence data for the β-tubulin (tub2), calmodulin (cmdA), histone H3 (his3) and partial translation elongation factor-1α (tef1) gene regions as well as their morphological features. Seven known species were identified, including Calonectria arbusta, Ca. asiatica, Ca. chinensis, Ca. eucalypti, Ca. hongkongensis, Ca. mossambicensis and Ca. pentaseptata. In addition, six novel taxa were collected and are described here as Ca. aciculata, Ca. honghensis, Ca. lantauensis, Ca. pseudoturangicola, Ca. pseudoyunnanensis, and Ca. yunnanensis spp. nov. Overall, the results reflect a high diversity of Calonectria species in China.

Draft genome sequences of five Calonectria species from Eucalyptus plantations in China, Celoporthe dispersa, Sporothrix phasma and Alectoria sarmentosa

“…To verify the identification of all the sequenced isolates, PCR amplification and sequencing of the partial elongation factor gene (tef1) for the extracted DNA was carried out on each isolate. The tef1 sequences were then aligned against the sequences which developed in previous studies (Chen et al 2011b;Li et al 2017). After the identification, a phylogenetic tree reflecting the position of these five species in relation to other Calonectria species was subsequently produced based on the four gene regions (cmdA, his3, tef1 and but2).…”

“…In the past 10 years, due to the influence of the phylogenetic species concept, many novel species of Calonectria have been described (Lombard et al 2010a;Lombard et al 2010b;Chen et al 2011b;Xu et al 2012;Alfenas et al 2013a;Alfenas et al 2013b;Lombard et al 2016;Li et al 2017;Liu and Chen 2017;Pham et al 2019). This genus currently includes 171 recognized species residing in 10 different species complexes.…”

“…This genus currently includes 171 recognized species residing in 10 different species complexes. Among these, 34 species, belonging to C. candelabra, C. cohounii, C. cylindrospora, C. kyotensis and C. reteaudii species complexes, were first discovered and described from China (Lombard et al 2016;Li et al 2017;Liu and Chen 2017;Pham et al 2019). In 2015, a survey conducted in a relatively small area in southern China led to the discovery of 18 novel species from soil and symptomatic Eucalyptus plant tissues (Chen et al 2011b;Lombard et al 2015).…”

“…Maximum likelihood tree based on partial gene sequences of cmdA, his3, tef1 and but2 gene sequences(Chen et al 2011b;Li et al 2017;Liu and Chen 2017;Pham et al 2019). Bootstrap values ≥65% are shown.…”

Variation in Botryosphaeriaceae from Eucalyptus plantations in YunNan Province in southwestern China across a climatic gradient

“…In recent years, Eucalyptus plantations in China have faced significant health threats from different pathogens, including species in the Botryosphaeriaceae (Chen et al 2011 ), Cryphonectriaceae (Chen et al 2010 ; Wang et al 2018 ) and Teratosphaeriaceae (Burgess et al 2006a ), as well as Botrytis (Liu et al 2016 ), Calonectria (Lombard et al 2010 ; Li et al 2017 ), Ceratocystis (Chen et al 2013 ), Quambalaria (Zhou et al 2007 ; Chen et al 2017 ) and Ralstonia (Carstensen et al 2017 ). Of these, Botryosphaeriaceae are amongst the most widespread and common associated with Eucalyptus plantations in southern China (Chen et al 2011 ; Li et al 2018 ).…”