Naslov
Biological control of chestnut blight: an interplay between chestnut, fungus Cryphonectria parasitica and Cryphonectria hypovirus 1

Autori
Ćurković-Perica, Mirna ; Ježić, Marin ; Krstin, Ljiljana ; Katanić, Zorana ; Nuskern, Lucija ; Poljak, Igor ; Idžojtić, Marilena

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
OBC-WPRS Bulletin, Preceedings of the Meeting "Biocontrol and Microbial Ecology" / Koch, U. ; Herz, A. - Darmstadt : International Organization for Biological and Integrated Control of Noxious Animals and Plants, West Palearctic Regional Section (IOBC-WPRS), 2016, 95-97

ISBN
978-92-9067-301-9

Skup
XIV Meeting of the IOBC-WPRS Working Group Biological Control of Fungal and Bacterial Plant Pathogens

Mjesto i datum
Berlin, Njemačka, 12.09.2016. - 15.09.2016

Vrsta sudjelovanja
Poster

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
hypovirulence ; chestnut genotype ; chestnut susceptibility and recovery ; virus efficiency

Sažetak
Chestnut blight is a disease caused by the fungus Cryphonectria parasitica Murrill Barr. This aggressive ascomycete infects bark and cambium of the sweet chestnut trees through wounds, and induces bark cankers which can lead to dieback of the distal parts of the plant, after girdling branches or the entire tree trunk (Heiniger & Rigling, 1994). C. parasitica had been accidentally introduced from Asia to North America and Europe and caused devastation of Castanea dentata and C. sativa populations, respectively. However, this severe disease can be controlled by naturally-occurring hypovirus Cryphonectria hypovirus 1 (CHV-1) which significantly reduces fungal virulence, sexual reproduction, pigmentation and sporulation (Chen & Nuss, 1999). Hypovirulent (CHV-1 infected) C. parasitica strains do not induce lethal cankers on chestnut trees. Moreover, they cause healing of cankers which were previously induced by virulent fungal strains (Heiniger & Rigling, 1994). The hypovirus can be transmitted from infected to non-infected C. parasitica strains via hyphal anastomosis, but the transmission is limited by the vegetative incompatibility vic system (Cortesi & Milgroom, 1998 ; Cortesi et al., 2001). CHV-1 is therefore transmitted between fungal strains belonging to the same vegetative incompatibility (vc) type, but between strains that belong to different vc types transmission rate is considerably lower or transmission does not happen at all (Cortesi et al., 2001). The hypovirus can also be transmitted via asexual conidia, but not via sexual ascospores (Peever et al., 2000 ; Prospero et al., 2006). In Europe CHV-1 occurs as several subtypes: I, F1, F2 and E/D (Prospero & Rigling, 2013) that differ in their virulence towards C. parasitica (Bryner & Rigling, 2011). French subtypes F1 and F2 of CHV-1 are believed to be more virulent towards C. parasitica and inhibit its growth and sporulation more than Italian subtype I (Robin et al., 2010). The importance of the use of specific virus isolates belonging to certain CHV-1 subtype in biological control had been studied before, but three lateral interaction of sweet chestnut, pathogen C. parasitica and biocontrol agent – CHV-1 has been only recently studied by our team (Ježić et al., 2014 ; Krstin et al., submitted). It was found that chestnut genotype contributes a lot to this three-lateral interaction. Both, susceptibility (Krstin et al., submitted) as well as recovery (Ježić et al., 2014) are considerably influenced by chestnut genotype, and therefore not only the genotypes of the fungus and virus, but also of the chestnut are important for successful biocontrol. We found out that marrons, sweet chestnut cultivars obtained through selection and propagated by grafting, that are grown primarily for the production of large quality fruits, are especially vulnerable to chestnut blight. In the presence of naturally-occurring hypovirulence, these trees recover with much lower frequency than trees from naturally growing chestnut population in 96 the same area. However, there is a difference is susceptibility of naturally growing trees as well, and certain hypovirulent fungal strains harboring specific virus isolates are more or less efficient against chestnut blight depending on chestnut genotype. Therefore, generally efficient hypovirulent C. parasitica strain does not exist, only strains which are efficient on majority of chestnut genotypes. Furthermore, as opposed to previously published results that imply higher virulence of French than Italian CHV-1 subtypes towards chestnut blight fungus, our results reveal that some virus isolates that belong to subtype I, which is widespread in Croatia and neighboring countries (Krstin et al., 2008 ; 2011) have equal effect on fungal host as the strong isolate CHV-1/EP713 that belongs to F subtype.

Izvorni jezik
Engleski

Znanstvena područja
Biologija, Šumarstvo

POVEZANOST RADA