Diaporthe nebulae sp. nov. and First Report of D. cynaroidis, D. novem, and D. serafiniae on Grapevines in South Africa

Abstract

Diaporthe species cause Phomopsis cane and leaf spot as well as Phomopsis dieback on grapevines. Symptoms of Phomopsis dieback have increasingly been observed over the past few years. In order to assess the current status of Diaporthe on grapevines in the Western Cape Province of South Africa, isolations were made from dormant grafted nursery vines, dormant rootstock canes, and dying or dead spurs of field vines. Cultures identified as Diaporthe based on morphological features were further identified to species level by sequencing the internal transcribed spacers (ITS) 1 and 2 and 5.8S rRNA and, for a representative subsample of isolates, the partial beta-tubulin (tub2) and translation elongation factor 1-alpha (EF1-α) genes. Phylogenetic analysis of the combined ITS, tub2, and EF1-α data revealed nine Diaporthe species associated with grapevines during this survey. One of these represents a new species, D. nebulae sp. nov., and three other species, namely D. novem, D. cynaroidis, and D. serafiniae, are reported on grapevines in South Africa for the first time. Species-specific primers were designed for PCR identification of D. ampelina, D. ambigua, and D. foeniculina. Pathogenicity studies conducted on detached grapevine shoots indicated D. ampelina, D. novem, and D. nebulae sp. nov. as the most virulent species.

Identification and Characterization of Diaporthe spp. Associated with Twig Cankers and Shoot Blight of Almonds in Spain

“…It is interesting to note that the ITS and tub sequences of two Diaporthe isolates, namely Phomopsis sp. 5 (PMM 1657 and PMM 1660), which were collected from V. vinifera in South Africa [41,42], showed 100% identity with the ITS and tub sequences of D. mediterranea. Further studies including other loci would be needed to resolve the identity of the South African isolates (PMM 1657 and PMM 1660).…”

“…The BLASTn search showed 100% identity with the available sequences (ITS and tub) of two isolates named Phomopsis sp. 5 (PMM 1657 and PMM 1660), collected from Vitis vinifera in South Africa [41,42], which were not described as new species by any of the authors. Nevertheless, other loci are needed to better resolve the identity of these isolates.…”

High Genetic Diversity and Species Complexity of Diaporthe Associated With Grapevine Dieback in China

“…These records are related to the following 27 Diaporthe species: Diaporthe ambigua (D. ambigua) (Dissanayake et al, 2017), D. ampelina (Úrbez-Torres et al, 2013), Diaporthe amygdali (D. amygdali) (Gomes et al, 2013; Guarnaccia et al, 2018), Diaporthe australafricana (D. australafricana) (Gomes et al, 2013), Diaporthe baccae (D. baccae), D. bohemiae, Diaporthe celeris (D. celeris) (Guarnaccia et al, 2018), Diaporthe chamaeropis (D. chamaeropis) (Lawrence et al, 2015), Diaporthe. Cynaroidis (Lesuthu et al, 2019) Diaporthe cytosporella (D. cytosporella), Diaporthe eres (D. eres), D. foeniculina, Diaporthe helianthi (D. helianthi) (Dissanayake et al, 2017; Guarnaccia et al, 2018; Farr and Rossman, 2019), Diaporthe hispaniae (D. hispaniae), D. hongkongensis (Dissanayake et al, 2017), Diaporthe hungariae (D. hungariae) (Guarnaccia et al, 2018), D. kyushuensis (Kajitani and Kanematsu, 2000), D. nebulae (Lesuthu et al, 2019) Diaporthe neotheicola (D. neotheicola) (Úrbez-Torres et al, 2013), Diaporthe nobilis (D. nobilis) (Dissanayake et al, 2017), D. novem (Lawrence et al, 2015), D. perjuncta (Mostert et al, 2001), Diaporthe perniciosa (D. perniciosa) (Stoykow and Denchev, 2006), D. phaseolorum (Dissanayake et al, 2017), Diaporthe rudis (D. rudis) (Guarnaccia et al, 2018), Diaporthe serafiniae (D. serafiniae) (Lesuthu et al, 2019), and D. sojae (Dissanayake et al, 2017). Among these species D. ampelina is the mostly reported species with 42 records in 12 countries.…”

“…More than one Diaporthe species is frequently reported as causative agents from one country (Dissanayake et al, 2015a; Guarnaccia et al, 2018). Currently, 27 species have been identified as causal organisms of Diaporthe dieback in grape-producing countries worldwide (Mostert et al, 2001; Van Niekerk et al, 2005; Udayanga et al, 2011, 2014a,b; White et al, 2011; Baumgartner et al, 2013; Úrbez-Torres et al, 2013; Hyde et al, 2014; Dissanayake et al, 2015a; Guarnaccia et al, 2018; Lesuthu et al, 2019). Even though these species characterized under the one disease, disease symptoms, and aggressiveness are varying according to the species.…”

“…Diaporthe perjuncta (D. perjuncta) and D. ampelina caused cane bleaching (Kuo and Leu, 1998; Kajitani and Kanematsu, 2000; Mostert et al, 2001; Van Niekerk et al, 2005; Rawnsley et al, 2006). Lesuthu et al (2019) showed that D. ampelina, Diaporthe novem (D. novem) , and Diaporthe nebulae (D. nebulae) as the most virulent species of Diaporthe associated with grapevines in South Africa. Diaporthe eres was found as a weak to moderate pathogen in several different studies (Kaliterna et al, 2012; Baumgartner et al, 2013).…”