Isozyme variability among isolates of <i>Phytophthora cinnamomi</i> from Australia and Papua New Guinea

Old, K.M.; Moran, G. F.; Bell, J. C.

doi:10.1139/b84-274

Cited by 74 publications

(61 citation statements)

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“…Our findings support previous studies revealing the limited genetic diversity in P. cinnamomi regardless of the extremely diverse environments it colonized (Dobrowolski et al 2003;Duan et al 2008;Eggers et al 2012;Linde et al 1997Linde et al , 1999Old et al 1984Old et al , 1988. Given the low genetic diversity seen in P. cinnamomi in our study, as well as in other regions where the population is primarily dominated by the A2 mating type, inbreeding becomes the means of reproduction (Lamour and Kamoun 2009).…”

Section: Discussionsupporting

confidence: 91%

Genotypic Diversity of Phytophthora cinnamomi and P. plurivora in Maryland’s Nurseries and Mid-Atlantic Forests

2017

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Genetic diversity of two Phytophthora spp.-P. cinnamomi (102 isolates), commonly encountered in Maryland nurseries and forests in the MidAtlantic United States, and P. plurivora (186 isolates), a species common in nurseries-was characterized using amplified fragment length polymorphism. Expected heterozygosity and other indices suggested a lower level of diversity among P. cinnamomi than P. plurivora isolates. Hierarchical clustering showed P. cinnamomi isolates separated into four clusters, and two of the largest clusters were closely related, containing 80% of the isolates. In contrast, P. plurivora isolates separated into six clusters, one of which included approximately 40% of the isolates. P. plurivora isolates recovered from the environment (e.g., soil and water) were genotypically more diverse than those found causing lesions. For both species, isolate origin (forest versus nursery or among nurseries) was a significant factor of heterozygosity. Clonal groups existed within P. cinnamomi and P. plurivora and included isolates from both forest and nurseries, suggesting that a pathway from nurseries to forests or vice versa exists.The genus Phytophthora includes numerous species that are among the most significant plant pathogens worldwide. As a result, the genus has been the focus of many population biology studies (Bhat and Browne

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Section: Discussionsupporting

confidence: 91%

Genotypic Diversity of Phytophthora cinnamomi and P. plurivora in Maryland’s Nurseries and Mid-Atlantic Forests

2017

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“…Phytophthora zoospores are motile and are chemiotactically attracted to the roots, where they encyst and secrete a number of proteins that glue them to the root surface and facilitate the infection (Hardham and Cahill 2010). The center of origin of P. cinnamomi is unknown, although Papua New Guinea seems the most likely center, given the high level of genetic diversity found among isolates of P. cinnamomi in this tropical region (Old et al 1984). Although P. cinnamomi is probably native to tropical regions, this pathogen has become invasive in many Mediterranean areas characterized by prolonged and severe drought conditions (Shearer et al 2004).…”

Section: Root Pathogensmentioning

confidence: 99%

Endemic and Emerging Pathogens Threatening Cork Oak Trees: Management Options for Conserving a Unique Forest Ecosystem

et al. 2016

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Cork oak (Quercus suber) forests are economically and culturally intertwined with the inhabitants of the Mediterranean basin and characterize its rural landscape. These forests cover over two million hectares in the western Mediterranean basin and sustain a rich biodiversity of endemisms as well as representing an important source of income derived from cork production. Currently cork oak forests are threatened by several factors including human-mediated disturbances such as poor or inappropriate management practices, adverse environmental conditions (irregular water regime with prolonged drought periods), and attacks of pathogens and pests. All these adverse factors can interact, causing a complex disease commonly known as “oak decline.” Despite the numerous investigations carried out so far, decline continues to be the main pathological problem of cork oak forests because of its complex etiology and the resulting difficulties in defining suitable control strategies. An overview of the literature indicates that several pathogenic fungi and oomycota can play a primary role in the etiology of this syndrome. Therefore, the aim of this review is to analyze the recent advances achieved regarding the bio-ecology of the endemic and emerging pathogens that threaten cork oak trees with particular emphasis on the species more directly involved in oak decline. Moreover, the effect of climate change on the host-pathogen interactions, a task fundamental for making useful decisions and managing cork oak forests properly, is considered.

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“…Eleven isolates of P. cinnamomi from an Australian-wide culture collection (CSIRO, Canberra) which have a known range of pathogenicity, isozyme type and mating type (Dudzinski, Old & Gibbs, 1993), 14 isolates from PNG (Old, Moran & Bell, 1984) and 10 recent isolates from the northern jarrah (Eucalyptus marginata Donn ex Sm.) forest in the southwest of WA were used in this study.…”

Section: Isolatesmentioning

confidence: 99%

“…The Australianwide isolates (four A1 and seven A2 mating types) and 14 PNG isolates (six A1 and eight A2 mating types) represent a wide range of isozyme types (Old et al, 1984) or electrophoretic types called CINN (Oudemans & Coffey, 1991). Matings involved isozyme types A1 (1), A2 (1) and A2 (2) called respectively electrophoretic type CINN 2, CINN 4 and CINN 5 ; and CINN 6 and CINN 7 for which no isozyme type was named although the isozyme variants were described by Old et al (1984). The WA isolates were from Cape Hope (1) and Alcoa of Australia Limited minesites at Willowdale (4), Jarrahdale (4) and Huntly (1).…”

Section: Isolatesmentioning

confidence: 99%

The role of paragynous and amphigynous antheridia in sexual reproduction of Phytophthora cinnamomi

Hüberli

Tommerup

Hardy

1997

Mycological Research

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The morphology of gametangia was examined in 43 pairs of isolates (mating types A1iA2 ; 11 A1 and 24 A2 isolates ; five isozyme\electrophoretic types) of Phytophthora cinnamomi. An amphigynous antheridium always formed with each oogonium. However, in 41 of the crosses a proportion (39 had 0n2-10 % and two had 30 %) of oogonia also consistently had single or multiple paragynous antheridia. Single or multiple paragynous antheridia formed concurrently with amphigynous ones during the period of gametangial production in paired colonies. Where there were multiple paragynous antheridia associated with an oogonium, sometimes additional antheridia formed after fertilization or even after oospores were visible. Developmental studies showed that when meiosis in amphigynous and paragynous antheridia was simultaneous, fertilization tubes developed synchronously from both. However, cytological examination indicated that either a nucleus from an amphigynous or a paragynous antheridium fertilized the oosphere. Observations of paragynous and amphigynous, and amphigynous-only associations suggested that fertilization from either type of antheridium only occurred when meiosis in the oogonium was nearly synchronous with that of the antheridium. Asynchronous meiosis between oogonia and antheridia may contribute to failed fertilization and aborted oospore development. This appears to be the first description of paragynous antheridia in P. cinnamomi and the second observation of oogonia with both paragynous and amphigynous antheridia in a heterothallic Phytophthora species. Moreover, the development of both paragynous and amphigynous antheridia with an oogonium is rare in Phytophthora, as is the development of multiple antheridia. Antheridial variation is a characteristic to be taken into account in isolate identification. Nuclei from paragynous antheridia appear able to fertilize oospheres and therefore, have a role in sexual reproduction.

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Isozyme variability among isolates of Phytophthora cinnamomi from Australia and Papua New Guinea

Cited by 74 publications

References 0 publications

Genotypic Diversity of Phytophthora cinnamomi and P. plurivora in Maryland’s Nurseries and Mid-Atlantic Forests

Genotypic Diversity of Phytophthora cinnamomi and P. plurivora in Maryland’s Nurseries and Mid-Atlantic Forests

Endemic and Emerging Pathogens Threatening Cork Oak Trees: Management Options for Conserving a Unique Forest Ecosystem

The role of paragynous and amphigynous antheridia in sexual reproduction of Phytophthora cinnamomi

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