TY - JOUR T1 - Genotypic diversity of Phytophthora cinnamomi and P. plurivora in Maryland’s nurseries and Mid-Atlantic forests JF - Phytopathology Y1 - 2017 A1 - Beaulieu, Justine A1 - Ford, Blain B A1 - Balci, Yilmaz AB -

Genetic diversity of two Phytophthora species, P. cinnamomi (102 isolates) and P. plurivora (186), commonly encountered in Maryland nurseries and forests in the Mid-Atlantic United States was characterized using amplified fragment length polymorphism (AFLP). Expected heterozygosity and other indices suggested a lower level of diversity among P. cinnamomi than P. plurivora. 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, water) were genotypically more diverse than those found causing lesions. For both species, isolate origin (forest vs. 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 visa verse exists.

UR - http://apsjournals.apsnet.org/doi/10.1094/PHYTO-05-16-0215-R JO - Phytopathology ER - TY - JOUR T1 - Genetic diversity of Phytophthora pluvialis, a pathogen of conifers, in New Zealand and the west coast of the United States of America JF - Plant Pathology Y1 - 2018 A1 - Brar, S. A1 - Tabima, J. F. A1 - McDougal, R. L. A1 - Dupont, P.-Y. A1 - Feau, N. A1 - Hamelin, R. C. A1 - Panda, P. A1 - LeBoldus, J. M. A1 - Grünwald, N. J. A1 - Hansen, E. M. A1 - Bradshaw, R. E. A1 - Williams, N. M. AB -

Phytophthora pluvialis is the causal agent of red needle cast on Pinus radiata in New Zealand. It was first isolated in 2008 but had previously been recovered from tanoak (Notholithocarpus densiflorus) and Douglas‐fir (Pseudotsuga menziesii) trees in Oregon, USA in 2002. Phytophthora pluvialis was subsequently described as a new species in 2013 and classified as a clade III Phytophthora species. The aim of this study was to gain a better understanding of the genetic diversity, population structure and origin of this pathogen. A total of 360 P. pluvialis isolates were collected from the USA and New Zealand. The genome sequences of two P. pluvialis isolates were used to identify 27 single nucleotide polymorphism (SNP) markers that were then used to genotype the two populations. The genotypic data showed that the USA population of P. pluvialis had twice the genetic diversity and a greater number of multilocus genotypes (MLGs) compared to the New Zealand population, with 126 and 24 MLGs, respectively. The majority of the subpopulations within the USA and New Zealand showed linkage disequilibrium. All subpopulations had a negative fixation index, indicating that clonal reproduction is prevalent in both countries. A minimum spanning network (MSN) showed two unique clusters of isolates in the New Zealand population, suggesting two potential introductions of P. pluvialis into New Zealand from the USA. There was no significant structure within the New Zealand or USA populations. This study provides novel insight into the genetic structure of P. pluvialis in New Zealand and the USA.

VL - 67 UR - https://onlinelibrary.wiley.com/doi/abs/10.1111/ppa.12812?campaign=wolacceptedarticle IS - 5 JO - Plant Pathol ER - TY - JOUR T1 - Genetic diversity of European populations of the oak fine-root pathogen Phytophthora quercina JF - Forest Pathology Y1 - 2005 A1 - Cooke, D. E. L. A1 - T. Jung A1 - Williams, N. A. A1 - Schubert, R. A1 - W. Oßwald A1 - Duncan, J. M. AB -

The recently discovered oak-specific fine root plant pathogen Phytophthora quercina is a significant factor in the current phase of European oak decline but its origins and ecology are poorly understood. A genome-wide analysis of 260 amplified fragment length polymorphism (AFLP) markers was used to examine the genetic diversity of 72 isolates from five oak species at 28 sites in Germany (particularly Bavaria), Italy, France, Hungary and the UK. Within-site diversity was examined at 16 sites. The limited genetic diversity (within and between sites) and lack of genetic substructuring according to geographic origin or host species suggest the rapid spread of a relatively recently introduced species. Two subgroups were distinguished and these may reflect an initial introduction of isolates of two different genetic backgrounds. The relatively low genetic diversity is probably because of the predominantly inbreeding (homothallic) nature of P. quercina. However, evidence of limited intra-site diversity, temporal variation and the lack of clonality within the European population suggest that some diversity is being maintained by occasional outcrossing and turnover of a reservoir of long-lived soil-borne oospore (sexually derived) inoculum.

VL - 35 IS - 1 JO - Forest Pathol ER - TY - JOUR T1 - Growth and sporulation of Phytophthora ramorum in vitro in response to temperature and light JF - Mycologia Y1 - 2006 A1 - Englander, Larry A1 - Browning, Marsha A1 - Tooley, Paul W. AB -

Phytophthora ramorum, recently found in the US, is causing concern for hardwood forests and the nursery industry. In an effort to identify some of the environmental limitations to growth and sporulation we undertook a laboratory study of four US and three European (EU) isolates. On V8 media, isolates grew when incubated at 2-28 C and produced chlamydospores at 8-28 C. Sporangia were produced at all temperatures tested: 10-30 C for US isolates and 6-26 C for EU isolates. Optimal temperatures were 16-26 C for growth, 14-26 C for chlamydospore production and 16-22 C for sporangia production. US isolates grew less and produced fewer spores when exposed to increasing doses of near-UV radiation (50-300 {micro}W/cm2) and visible radiation (250-1500 {micro}W/cm2). EU isolates were exposed to 300 {micro}W/cm2 near-UV only, which significantly reduced growth of one of three isolates and had no significant effect on spore production. In our studies P. ramorum tolerated a broad range of temperature and light conditions, which suggests that it is capable of establishment in a wide geographic area.

VL - 98 UR - http://www.mycologia.org/cgi/content/abstract/98/3/365 ER - TY - JOUR T1 - Gene × environment tests discriminate the new EU2 evolutionary lineage of Phytophthora ramorum and indicate that it is adaptively different JF - Forest Pathology Y1 - 2013 A1 - Franceschini, S. A1 - Webber, J. F. A1 - Sancisi-Frey, S. A1 - Brasier, C. M. AB -

A new evolutionary lineage of the destructive introduced tree pathogen Phytophthora ramorum, EU2 lineage, was recently discovered attacking larch and other hosts in Northern Ireland and south west Scotland, UK. Sixteen ‘medium × agar concentration × incubation temperature’ stress environments were tested to find a rapid and repeatable method to discriminate the known EU2 lineage from the EU1, NA1 and NA2 lineages in culture, in particular from the EU1 already prevalent across the UK; and to investigate whether EU2 might be adaptively different. At 28°C on both Carrot agar and V8 juice agar, the mean radial growth rates of all four lineages were significantly different, with NA2 > EU2 > EU1 > NA1. At this temperature, EU2 colonies were not only phenotypically distinct from EU1 and all other lineages but on average grew three times as fast as EU1. This indicates that EU2 is adaptively different from EU1. Twelve days growth in the environment ‘V8A/2% agar/28°C gave excellent discrimination of all four lineages in three repeat experiments, including clear discrimination of EU2 from EU1. Each lineage exhibited a distinctive colony pattern. The utility of this test environment was examined further by screening fresh UK isolates of unknown lineage from new larch outbreak sites alongside standard isolates. The lineage assignments predicted were corroborated by gene sequencing and RFLP profiling. These results also revealed that the EU2 lineage was present at several new larch sites in south west Scotland, whereas isolates from geographically adjacent areas such as the Isle of Mull, north west Scotland, the Isle of Man and north west England were all of EU1 lineage.

VL - 44 UR - http://dx.doi.org/10.1111/efp.12085 IS - 3 ER - TY - JOUR T1 - Genome sequences of Phytophthora enable translational plant disease management and accelerate research JF - Canadian Journal of Plant Pathology Y1 - 2012 A1 - Grünwald, Niklaus J. AB -

Whole and partial genome sequences are becoming available at an ever-increasing pace. For many plant pathogen systems, we are moving into the era of genome resequencing. The first Phytophthora genomes, P. ramorum and P. sojae, became available in 2004, followed shortly by P. infestans in 2006. Availability of whole genome sequences has provided rapid and immediate advances in several areas also resulting in many practical applications and critical new insights. Availability of comparative genome data facilitated discovery of new classes of effectors, such as the RxLR-dEER and crinkler effector families. Genome data also enabled development of molecular markers for population genomic approaches that provided critical new insights into the evolutionary history of species and clades of Phytophthora. Several select examples of advances resulting from comparative genomic approaches in a concerted effort of the Oomycete research community are reviewed.

VL - 34 UR - http://www.tandfonline.com/doi/abs/10.1080/07060661.2012.664568 ER - TY - JOUR T1 - Genetic characterization of the natural hybrid species Phytophthora alni as inferred from nuclear and mitochondrial DNA analyses JF - Fungal Genetics and Biology Y1 - 2006 A1 - Renaud Ioos A1 - Axelle Andrieux A1 - BenoÓt MarÁais A1 - Pascal Frey KW - Interspecific hybridization AB -

The different subspecies of Phytophthora alni, P. alni subsp. alni (Paa), P. alni subsp. uniformis (Pau), and P. alni subsp. multiformis (Pam), are recent and widespread pathogens of alder in Europe. They are believed to be a group of emergent heteroploid hybrids between two phylogenetically close Phytophthora species. Nuclear and mitochondrial DNA analyses were performed, using a broad collection of P. alni and two closely related species, P. cambivora and P. fragariae. (Paa) possesses three different alleles for each of the nuclear genes we studied, two of which are present in Pam as well, whereas the third matches the single allele present in Pau. Moreover, Paa displays common mtDNA patterns with both Pam and Pau. A combination of the data suggests that Paa may have been generated on several occasions by hybridization between Pam and Pau, or their respective ancestors. Pau might have P. cambivora as a species ancestor, whereas Pam seems to have either been generated itself by an ancient reticulation or by autopolyploidization.

VL - 43 UR - http://www.sciencedirect.com/science/article/B6WFV-4JS1TK3-1/2/aead0efc6dc22a393ebadec5b3211855 ER - TY - JOUR T1 - The genus Phytophthora anno 2012 JF - Phytopathology Y1 - 2012 A1 - Kroon, Laurens P. N. M. A1 - Brouwer, Henk A1 - de Cock, Arthur W. A. M. A1 - Govers, Francine AB -

Plant diseases caused by Phytophthora species will remain an ever increasing threat to agriculture and natural ecosystems. Phytophthora literally means plant destroyer, a name coined in the 19th century by Anton de Bary when he investigated the potato disease that set the stage for the Great Irish Famine. Phytophthora infestans, the causal agent of potato late blight, was the first species in a genus that at present has over 100 recognized members. In the last decade, the number of recognized Phytophthora species has nearly doubled and new species are added almost on a monthly basis. Here we present an overview of the 10 clades that are currently distinguished within the genus Phytophthora with special emphasis on new species that have been described since 1996 when Erwin and Ribeiro published the valuable monograph ‘Phytophthora diseases worldwide’ (35).

VL - 102 UR - http://apsjournals.apsnet.org/doi/abs/10.1094/PHYTO-01-11-0025 IS - 4 JO - Phytopathology ER - TY - JOUR T1 - Genetic diversity, sensitivity to phenylamide fungicides and aggressiveness of Phytophthora ramorum on Camellia, Rhododendron and Viburnum plants in Spain JF - Plant Pathology Y1 - 2011 A1 - Pérez-Sierra, A. A1 - Álvarez, L. A. A1 - Vercauteren, A. A1 - Heungens, K. A1 - Abad-Campos, P. KW - fungicide resistance KW - host origin KW - mefenoxam KW - metalaxyl KW - multilocus genotype KW - Sudden oak death AB -

Phytophthora ramorum has been detected in official plant health surveys on Rhododendron, Viburnum and Camellia in ornamental nurseries in northern Spain since 2003. A collection of 94 isolates of P. ramorum was obtained from 2003 to 2008 from plants with symptoms at different geographical locations. Isolates were identified based on morphology and sequence of the rDNA ITS region. Mating type, genetic variation, sensitivity to phenylamide fungicides and aggressiveness of these isolates were determined. All isolates belonged to the A1 mating type, ruling out the possibility of genetic recombination. Seven microsatellite markers were used to study genetic diversity; three out of the seven microsatellite markers were polymorphic within the Spanish population of P. ramorum. This study confirms that all Spanish isolates of P. ramorum belonged to the EU1 lineage. Twelve intralineage genotypes were detected, five that are unique to Spain (EU1MG38, EU1MG41, EU1MG37, EU1MG39 and EU1MG40) and seven that are also present in at least one other European country (EU1MG1, EU1MG29, EU1MG22, EU1MG13, EU1MG2, EU1MG18 and EU1MG26). Genotypes EU1MG37, EU1MG39 and EU1MG40 were isolated from Rhododendron from one region; EU1MG38 and EU1MG41 were isolated from Camellia from two different regions. Isolates of genotype EU1MG38 were resistant to metalaxyl and mefenoxam. The level of genetic diversity within the Spanish population of P. ramorum is limited and indicates a relatively recent clonal expansion.

PB - Blackwell Publishing Ltd VL - 60 UR - http://dx.doi.org/10.1111/j.1365-3059.2011.02485.x ER - TY - Generic T1 - Ground verification of Aerial survey for POC root disease Y1 - 2002 A1 - PNW Research Station, USDA-FS PB - PNW Research Station, USDA Forest Service, Forestry Sciences Laboratory UR - http://www.fs.fed.us/pnw/publications/brochure-misc.shtml ER - TY - JOUR T1 - Gomose da acácia-negra: etiologia, análise temporal, perdas e controle genético. JF - Boletim de Pesquisa e Desenvolvimento, Embrapa Florestas, Ministério da Agricultura Y1 - 2007 A1 - Santos, A. F. dos A1 - Luz, E.D.M.N. A1 - Maffia, L.A. A1 - Souza, J.T. AB -

Gummosis is one of the most serious phytosanitary problems of black wattle (Acacia mearnsii) in the State of Rio Grande do Sul, Brazil. The objectives of this work were: 1) to identify the species of Phytophthora associated with gummosis; 2) to analyze the temporal distribution of the gummosis; 3) to quantify losses caused by this disease; and 4) to rank black wattle lines based on resistance to gummosis. The major results were: Phytophthora nicotianae and P. boehmeriae are the causal agent of gummosis on black-wattle in Brazil. This disease was found in all the surveyed black-wattle plantations and the species P. nicotianae was the major species found in the samples, suggesting that this is the main species causing this disease in Brazil. It was found two kinds of symptoms: 1) gummosis at the base of the trunks, associated to P. nicotianae; e 2) gummosis spread on the trunk, associated to P. boehmeriae. Plants killed by gummosis or other causes showed exponential growth, and started to die after 34 months. Plants showing gummosis had losses ranging from 3,5 to 0,5% for bark and timber production, respectively. Both, natural and artificial inoculations assays showed variation on the resistance of plants to gummosis.

A gomose é um dos mais sérios problemas fitossanitários da acácia-negra (Acacia mearnsii) no Rio Grande do Sul. Este trabalho teve como objetivos: 1) identificar a(s) espécie(s) de Phytophthora associada(s) à gomose; 2) analisar a distribuição temporal da gomose; 3) quantificar as perdas causadas pela doença; e 4) agrupar os materiais genéticos de acácia-negra de acordo com o nível de resistência à gomose. Os principais resultados foram: Phytophthora nicotianae e P.boehmeriae são os agentes causais da gomose da acácia-negra no Brasil. A gomose de Phytophthora foi encontrada em todos os plantios de acácia-negra e, no levantamento, evidenciou-se a predominância de P. nicotianae, mostrando que este patógeno é o principal agente da gomose da acácia-negra no Brasil. As avaliações em plantios comerciais em idade de corte apresentaram até 48 % de indivíduos atacados. Tanto plantas mortas por outras causas quanto plantas mortas por gomose cresceram exponencialmente, e as mortes começaram a partir do 34º mês. Os dados mostraram perdas de produção de até 3,5 % para casca e até 0,5 % para madeira nas árvores com gomose. Tanto por infecção natural quanto por inoculação artificial, ocorreram variações entre as procedências quanto a resistência à gomose.

VL - 31 UR - http://www.infoteca.cnptia.embrapa.br/infoteca/bitstream/doc/312305/1/BPD31CD.pdf ER - TY - JOUR T1 - A gomose da acácia-negra no Brasil: a review JF - Summa Phytopathologica Y1 - 2007 A1 - Santos, A. F. dos A1 - Luz, E. D. M. N. AB -

A acácia-negra (Acacia mearnsii) é cultivada no Brasil, especialmente no Estado do Rio Grande do Sul, visando tanto à produção de tanino, a partir da casca, quanto o uso da madeira para papel, celulose, carvão, lenha e chapas de aglomerados. A gomose causada por Phytophthora nicotianae e P. boehmeriae, é o seu principal problema fitossanitário. Discute-se nesta revisão a existência de dois padrões distintos de sintomatologia da gomose de Phytophthora que têm sido observados nas plantações brasileiras: gomose basal, associada a P. nicotianae, e gomose generalizada, mais associada a P. boehmeriae. São discutidos aspectos relacionados à etiologia, à epidemiologia e às estratégias de controle.

The black wattle (Acacia mearnsii ) is cultivated in Brazil for bark tannin, paper, cellulose, plywood, charcoal and firewood production. Gummosis of Phytophthora, caused by P. nicotianae and P. boehmeriae is the main disease problem on black wattle. The existence of two distinct symptom patterns observed on plants in the commercial fields are: butt gummosis which is associated with P. nicotianae and general gummosis more related to P. boehmeriae. Etiological, epidemiological and control aspects of this disease are presented and discussed on this review.

VL - 33 UR - https://doi.org/10.1590/s0100-54052007000200002 IS - 2 JO - Summa phytopathol. ER - TY - JOUR T1 - Growth and productivity of New Zealand kauri (Agathis australis (D.Don) Lindl.) in planted forests JF - New Zealand Journal of Forestry Science Y1 - 2014 A1 - Steward, Gregory A A1 - Kimberley, Mark O A1 - Mason, Euan G A1 - Dungey, Heidi S AB -

Background

The establishment of even-aged planted stands of New Zealand kauri (Agathis australis (D.Don) Lindl.) for timber has been constrained by a lack of quantitative information on productivity and rotation length on which forest management and investment decisions could be made.

Methods

Stand-level models of height and basal area against time were developed (as well as a stand-volume function to calculate volume from height and basal area) based on planted stands that were up to 83-years old and represented planting sites both within and outside the current natural range of the species.

Results

Planted kauri was shown to be slow to establish with little height growth for the first five years after planting. Similar trends were observed for basal area and whole-tree volume development. A Schumacher equation with local slope parameter and asymptote bounded at 45 m gave the best fit for height, while a von Bertalanffy-Richards equation in difference form with local slope parameter gave the best fit for basal area. For plantations with an average site index (20.4), height was predicted to be 22.3 m in height at age 60, with a basal area of 78.1 m2 ha?1. Whole-tree volume was predicted to be 702 m3 ha?1. Predicted volume mean annual increment was 11.7 m3 ha?1 yr?1for all stands at age 60. From age 20-60 years, stands with a higher site index had a volume mean annual increment of 18.6 m3 ha?1 yr?1. The best stand exceeded 20 m3 ha?1 yr?1.

Conclusions

This study indicates an opportunity to grow kauri in plantations on selected good-quality sites over rotations of 60-80 years or less.

VL - 44 UR - http://www.nzjforestryscience.com/content/44/1/27http://link.springer.com/content/pdf/10.1186/s40490-014-0027-2 IS - 27 JO - N.Z. j. of For. Sci. ER - TY - JOUR T1 - Genome sequences of six Phytophthora species associated with forests in New Zealand JF - Genomics Data Y1 - 2016 A1 - Studholme, D.J. A1 - McDougal, R.L. A1 - Sambles, C. A1 - Hansen, E. A1 - Hardy, G. A1 - Grant, M. A1 - Ganley, R.J. A1 - Williams, N.M. AB -
In New Zealand there has been a long association of Phytophthora diseases in forests, nurseries, remnant plantings and horticultural crops. However, new Phytophthora diseases of trees have recently emerged. Genome sequencing has been performed for 12 Phytophthora isolates, from six species: Phytophthora pluvialis, P. kernoviae, P. cinnamomi, P. agathidicida, P. multivora and P. taxon Totara. These sequences will enable comparative analyses to identify potential virulence strategies and ultimately facilitate better control strategies. This Whole Genome Shotgun data have been deposited in DDBJ/ENA/GenBank under the accession numbers LGTT00000000, LGTU00000000, JPWV00000000, JPWU00000000, LGSK00000000, LGSJ00000000, LGTR00000000, LGTS00000000, LGSM00000000, LGSL00000000, LGSO00000000, and LGSN00000000.
VL - 7 UR - http://www.sciencedirect.com/science/article/pii/S2213596015300854 JO - Genomics Data ER - TY - JOUR T1 - Genome sequencing of oomycete isolates from Chile supports the New Zealand origin of Phytophthora kernoviae and makes available the first Nothophytophthora sp. genome JF - Molecular Plant Pathology Y1 - 2019 A1 - Studholme, David J. A1 - Panda, Preeti A1 - Sanfuentes von Stowasser, Eugenio A1 - González, Mariela A1 - Hill, Rowena A1 - Sambles, Christine A1 - Grant, Murray A1 - Williams, Nari M. A1 - McDougal, Rebecca L. AB -

Genome sequences were generated for six oomycete isolates collected from forests in Valdivia, Chile. Three of the isolates were identified morphologically as Phytophthora kernoviae, whereas two were similar to other clade 10 Phytophthora species. One isolate was tentatively identified as Nothophytophthora valdiviana based on nucleotide sequence similarity in the cytochrome oxidase 1 gene. This is the first genome sequence for this recently described genus. The genome assembly was more fragmented and contained many duplicated genes when compared with the other Phytophthora sequences. Comparative analyses were performed with genomic sequences of the P. kernoviae isolates from the UK and New Zealand. Although the potential New Zealand origin of P. kernoviae has been suggested, new isolations from Chile had cast doubt on this hypothesis. We present evidence supporting P. kernoviae as having originated in New Zealand. However, investigation of the diversity of oomycete species in Chile has been limited and warrants further exploration. We demonstrate the expediency of genomic analyses in determining phylogenetic relationships between isolates within new and often scantly represented taxonomic groups, such as Phytophthora clade 10 and Nothophytophthora. Data are available on GenBank via BioProject accession number PRJNA352331.

VL - 20 UR - https://bsppjournals.onlinelibrary.wiley.com/doi/full/10.1111/mpp.12765 IS - 3 JO - Molecular Plant Pathology ER - TY - JOUR T1 - Growth enhancement, amino acid synthesis and reduction in susceptibility towards Phytophthora megakarya by arbuscular mycorrhizal fungi inoculation in cocoa plants JF - Journal of Phytopathology Y1 - 2012 A1 - Tchameni, Séverin Nguemezi A1 - Nwaga, Dieudonné A1 - Wakam, Louise Nana A1 - Mangaptche Ngonkeu, Eddy Leonard A1 - Fokom, Raymond A1 - Kuaté, Jean A1 - Etoa, Francois-Xavier KW - amino acids KW - arbuscular mycorrhizal fungi KW - cocoa KW - Phytophthora megakarya KW - plant disease AB -

The effects of some selected arbuscular mycorrhizal (AM) fungi, Gigaspora margarita and Glomus mossae on the growth and the role of soluble amino acids of two contrasting cocoa cultivars (ICS84 tolerant and SNK10 sensitive) against black pod disease caused by Phytophthora megakarya were investigated. Root colonization by AM fungi is between 50 and 70% 18 weeks after planting. Tested AM fungi significantly increased all the plant growth parameters (height, number of leaves, shoot and root matter) and P uptake as compared to non-inoculated plants in pot experiments. AM fungi inoculated cocoa reduced the disease severity. Compared to the control, the soluble amino acid levels increased with inoculation of the AM fungi strains in the necrotic stems of disease on inoculated cocoa plants. Significant relationships between amino acids and disease severity observed for two cocoa cultivars imply that the induction of specific amino acids synthesized by leaves, such as arginine, cysteine and glutamic acid, may represent potential candidate molecules for adaptation of such cultivars to P. megakarya disease. Inoculating seedlings with AMF in nurseries could enhance the development of cocoa plants protected against P. megakarya.

PB - Blackwell Publishing Ltd VL - 160 UR - http://dx.doi.org/10.1111/j.1439-0434.2012.01888.x ER - TY - RPRT T1 - The gummosis of black wattle: a complex of disease Y1 - 1968 A1 - Zeijlemaker, F. C. J. JF - Wattle Research Institute PB - Wattle Research Institute CY - Pietermaritzburg, South Africa ER -