Vegetative compatibility grouping in Botrytis cinerea using sulphate non-utilizing mutants

Abstract

Twenty-one strains of Botrytis cinerea isolated from six plant species on ten sites throughout Israel, as well as a strain from France, were tested for vegetative and mycelial incompatibility, pathogenicity, resistance to the fungicides carbendazim and iprodione, and colony morphology. Selenate-resistant mutants were isolated from the strains as spontaneous, fastgrowing sectors arising from restricted colonies on medium amended with sodium selenate with a mean frequency of 0.04 sectors/colony; 81% of the sectors were sulphate non-utilizing (sul) mutants. One hundred and four sul mutants were divided into two complementary groups: resistant (66 mutants) and sensitive to chromate. Based on compatibility reactions between chromate-resistant and chromate-sensitive sul mutants, 12 strains were compatible only with themselves and were each classified as belonging to different vegetative compatibility groups (VCGs). Nine strains were each compatible with one to three other strains, and were assembled into three multi-member VCGs. Mycelial incompatibility between wild-type strains (barrage), in the form of a zone of dark pigmentation or sparse mycelium with or without dark pigmentation of the agar along the line of confrontation, was observed for 70% of the inter-strain pairings. There was no correspondence in compatibility between strains revealed by two approaches: strains in different VCGs did not necessarily produce a barrage. However, self-compatibility was observed both as heterokaryon formation between complementary sul mutants and as an absence of barrages between mycelia of wild-type strains; wild-type strains belonging to the same VCG did not exhibit strong barrages, although weak antagonistic reactions were observed. Strains in two multimember VCGs showed the same patterns of resistance to carbendazim and iprodione; the third multi-member VCG contained isolates with different patterns of resistance. Four morphological types were revealed among wild-type strains: conidial (five strains), sclerotial (six strains), intermediate (ten strains), and mycelial (one strain). On bean leaves, conidial strains were more aggressive than sclerotial strains.

Novel Hypovirulence-Associated RNA Mycovirus in the Plant-Pathogenic Fungus Botrytis cinerea: Molecular and Biological Characterization

“…Vegetative incompatibility has been detected in populations of B. cinerea (26,27). Wu et al (23,24) reported that through hyphal contact, BcMV1 could be transmitted to single-conidium (SC) virulent isolates of B. cinerea strain CanBc-1, from which BcMV1 was originally isolated, but could not be transmitted to a different virulent strain, CanBc-2, of B. cinerea.…”

Characterisation of Growth Variability and Mycelial Compatibility of Botrytis Cinerea Isolates Originated from Apple and Strawberry in Lithuania

“…Although direct correlation between VCGs and MCGs has not been demonstrated in B. cinerea, MCG can reveal the potential genetic diversity in the particular population of the pathogen (Fillinger and Elad, 2016). In general, VCGs and MCGs in B. cinerea populations are not sufficiently studied (Korolev et al, 2008;Burgess et al, 2009;Fernandez et al, 2014;Kumari et al, 2014;Fillinger and Elad, 2016). Korolev et al (2008) found that interstrain incompatibility was widespread among tested B. cinerea strains and the dark pigmentation zone along the line of confrontation was observed in 36% of the tested combinations of strains.…”

“…In general, VCGs and MCGs in B. cinerea populations are not sufficiently studied (Korolev et al, 2008;Burgess et al, 2009;Fernandez et al, 2014;Kumari et al, 2014;Fillinger and Elad, 2016). Korolev et al (2008) found that interstrain incompatibility was widespread among tested B. cinerea strains and the dark pigmentation zone along the line of confrontation was observed in 36% of the tested combinations of strains. In this study, mycelial compatibility and incompatibility among B. cinerea isolates from strawberry and apple in Lithuania were analysed for the first time.…”

“…VCG inter-strain pairings showed that 93% of the tested B. cinerea strains were incompatible and only 7% were compatible (Korolev et al, 2008). Two genetically different groups are known for B. cinerea, which are considered as cryptic species (Fournier et al, 2005).…”

“…In the study by Fournier et al (2005) B. cinerea isolates from group I formed unique single VCG while isolates from group II formed several VCGs. MCGs are used for B. cinerea characterisation and indicate incompatibility or compatibility in B. cinerea, although direct correlation with VCGs has not been found (Fournier et al, 2005;Korolev et al, 2008;Fillinger and Elad, 2016).…”