Characterization and development of qPCR for early detection and quantification of Pseudocercospora macadamiae at different stages of infection process

Ong, Catherine; Jm, Henderson; Akinsanmi, Olufemi A.

doi:10.1007/s10658-016-0982-y

Cited by 4 publications

(6 citation statements)

References 22 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…As a single‐copy gene, TEF ‐ 1α is an ideal candidate that functions well for species delimitation within Pestalotiopsis (Maharachchikumbura et al, 2012). In macadamia, the TEF ‐ 1α gene has successfully been used in a qPCR assay to detect and quantify Pseudocercospora macadamiae (Ong et al, 2017).…”

Section: Discussionmentioning

confidence: 99%

“…Quantitative real‐time PCR (qPCR) that detects and estimates very low quantities of DNA in different samples can be used to study the presence of specific fungal spores more precisely (Pham et al, 2003). In macadamia, Ong et al, (2017) developed two qPCR assays based on internal transcribed spacer (ITS) and translation elongation factor 1‐alpha ( TEF ‐ 1α ) gene loci to detect and quantify the husk spot pathogen Pseudocercospora macadamiae . Their assays were used to detect infection before symptom expression and quantify fungal biomass at different disease development phases (Ong et al, 2017).…”

Section: Introductionmentioning

confidence: 99%

“…In macadamia, Ong et al, (2017) developed two qPCR assays based on internal transcribed spacer (ITS) and translation elongation factor 1‐alpha ( TEF ‐ 1α ) gene loci to detect and quantify the husk spot pathogen Pseudocercospora macadamiae . Their assays were used to detect infection before symptom expression and quantify fungal biomass at different disease development phases (Ong et al, 2017). There is no information on any qPCR assays for species of Pestalotiopsis and Neopestalotiopsis .…”

Section: Introductionmentioning

confidence: 99%

See 2 more Smart Citations

Molecular methods for the detection and quantification of Pestalotiopsis and Neopestalotiopsis inoculum associated with macadamia

2021

View full text Add to dashboard Cite

Pestalotiopsis blight and leaf spot in macadamia are caused by species of Pestalotiopsis and Neopestalotiopsis. Conidia produced by these pathogens are mostly dispersed by wind and rain splash and are the primary infecting propagules. Rapid detection and quantification of airborne conidia are essential to determine the seasonal dynamics of inoculum and critical infection periods in macadamia orchards. A quantitative PCR (qPCR) using a new primer pair and a hydrolysis probe was developed to detect and quantify airborne conidia of Pestalotiopsis and Neopestalotiopsis species. The amplification efficiency of the qPCR was 96.4% and the assay had a limit of detection of 400 fg of Pestalotiopsis/Neopestalotiopsis gDNA, which corresponds to approximately 10 conidia. The qPCR assay coupled with spore trapping was used to monitor airborne conidia dispersal under field conditions. The results showed that the assay is specific and sensitive for detecting and quantifying Pestalotiopsis/Neopestalotiopsis conidia in macadamia orchards. The detection and quantification of the pathogen inoculum will improve our understanding of disease epidemiology and the ability to manage these diseases in macadamia.

show abstract

Section: Discussionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Molecular methods for the detection and quantification of Pestalotiopsis and Neopestalotiopsis inoculum associated with macadamia

2021

View full text Add to dashboard Cite

show abstract

“…Symptoms become visible 5-8 weeks postpathogen penetration (Wright 1993), commencing as chlorotic flecks that become sclerified, and progress to tan, brown or black necrotic lesions (Miles et al 2009). The concentration of P. macadamiae DNA in infected tissue increases during early stages of symptom development (Ong et al 2017). Sporulation can occur on chlorotic tissue (Wright 1993), though the density of mycelia and conidial production appear to increase as lesions progress (Miles et al 2009).…”

Section: Introductionmentioning

confidence: 99%

“…Sporulation can occur on chlorotic tissue (Wright 1993), though the density of mycelia and conidial production appear to increase as lesions progress (Miles et al 2009). Early work identified that the disease is predominantly asexual (Akinsanmi and Drenth 2010), with the most recent genetic study finding P. macadamiae isolates to be clonal (Ong et al 2017).…”

Section: Introductionmentioning

confidence: 99%

Genetic parameters of husk spot resistance in macadamia breeding families

et al. 2023

View full text Add to dashboard Cite

Husk spot caused by the Pseudocercospora macadamiae fungus induces premature abscission of fruit in many industry standard macadamia cultivars. Fungicides and other management strategies add to farm costs, thus breeding for varietal resistance is important. Genetic parameters of husk spot symptom expression had not previously been estimated. To guide selection methods for field resistance, over 300 open-pollinated seedlings of 32 families and 24 parent genotypes were inoculated, and seven symptom expression traits were evaluated. Narrow-sense and broad-sense heritabilities were estimated, breeding values were predicted, and correlations between breeding values of trait pairs were tested for significance. The traits with the highest heritabilities were necrotic lesion number per fruit (H2 = 0.41–0.59; h2 = 0.21–0.30) and necrotic incidence (H2 = 0.19–0.27; h2 = 0.17–0.24). Breeding values of the two traits were highly correlated (r = 0.98; p < 0.001), suggesting that either trait could be used to indirectly select for the other. All genotypes expressed symptoms to some degree, however, breeding values for necrotic traits and symptom-induced premature abscission were low for clones and progeny of cultivar ‘HAES791’. Necrotic trait breeding values were also promising for progeny of cultivar ‘HAES246’ and clones of Australian Macadamia Breeding Program elite selection, ‘BAM263’. Having been identified as potentially partially resistant, these selections can now be further evaluated and used as parents of new progeny populations.

show abstract

Evaluation of In-Field Inoculation Methods for Characterization of Macadamia Germplasm to Husk Spot Incidence and Severity

et al. 2023

View full text Add to dashboard Cite

Husk spot, a fungal (Pseudocercospora macadamiae) disease of macadamia pericarps, induces premature abscission in several major commercial cultivars. Breeding for resistance to husk spot is a priority of the Australian macadamia industry. Due to the large tree size of macadamia and high numbers of progeny in breeding populations, inoculating for resistance screening is laborious and time consuming. Previously utilised methods included direct applications of P. macadamiae suspensions and hanging of bags of diseased husks above developing fruit in tree canopies. In this study, both methods were modified to allow for efficient application in large-scale breeding populations and their efficacy was evaluated. Two quantities of diseased husk per bag: ‘large’ (75 g) and ‘small’ (30 g) and two concentrations of sprayed P. macadamiae suspensions: 5 x 105 propagules/mL ‘stock’ and ‘dilute’ 2.5 x 105 propagules/mL were tested across two fruiting seasons. Treatments were compared against a control (sterile water) in commercial cultivars ‘A38’ and ‘A4’. Husk spot incidence and severity produced by small bags were significantly affected by season. A significant season effect was less common for other treatments. All four treatments infected over 50% of target fruit in each season, but the highest husk spot incidence across both seasons (≥85%) was produced from large bags. Overall, the large bags were the most reliable method for infection of target fruit. Results also demonstrate the importance of considering the effect of season when selecting husk spot inoculation methods.

show abstract

Characterization and development of qPCR for early detection and quantification of Pseudocercospora macadamiae at different stages of infection process

Cited by 4 publications

References 22 publications

Molecular methods for the detection and quantification of Pestalotiopsis and Neopestalotiopsis inoculum associated with macadamia

Molecular methods for the detection and quantification of Pestalotiopsis and Neopestalotiopsis inoculum associated with macadamia

Genetic parameters of husk spot resistance in macadamia breeding families

Evaluation of In-Field Inoculation Methods for Characterization of Macadamia Germplasm to Husk Spot Incidence and Severity

Contact Info

Product

Resources

About