Detached Root Inoculation -- A New Method to Evaluate Resistance to Phytophthora Root Rot in Avocado Trees

Zilberstein, M.

doi:10.1094/phyto-77-841

Cited by 10 publications

(4 citation statements)

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“…The most commonly observed effect in infection is the loss of electrolytes due to disruption of the cell membrane, which may occur via pathogen enzymes or toxins and often leads to a dramatic increase in ion movement especially K + and H + through the cell membrane (Agrios 1997). The quantification of cell and tissue electrolyte leakage was used reliably to screen avocado rootstocks for resistance to phytophthora root rot (Zilberstein and Pinkas 1987). This technique was also employed to compare and identify disease tolerant and susceptible citrus infected with two Phytophthora species (Widmer et al 1998).…”

Section: Discussionmentioning

confidence: 99%

Pathogenicity of indole-3-acetic acid producing fungus Fusarium delphinoides strain GPK towards chickpea and pigeon pea

2011

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An indole-3-acetic acid (IAA) producing fungal strain was isolated from chickpea grown rhizospheric soil samples. Based on morphological and Internal Transcribed Spacer (ITS) region sequence analysis the new isolate was identified as Fusarium delphinoides. The Fusarium delphinoides strain produces and secretes IAA in-vitro as identified by HPLC and Mass spectrometry. The IAA production is dependent on tryptophan (Trp) as a nitrogen source in the medium. The IAA production is influenced by growth conditions such as pH of the medium, concentration of Trp and the nature of the carbon source. Additional nitrogen sources repress Trp dependent IAA production. Glucose and Trp served as the best carbon and nitrogen sources respectively. Pathogenicity of Fusarium delphinoides towards the plants was tested by electrolyte, nutrient leakage analysis and also by scoring the disease symptoms. Two cultivars of chickpea (ICCV-10 and L-550) and two cultivars of pigeon pea (Maruti and PT-221) were assessed for the pathogenicity by inoculating with spores of Fusarium delphinoides. The inoculation induced symptoms of Fusarium wilt as in the case of Fusarium oxysporum f. sp. ciceris (FOC), a known pathogen causing Fusarium wilt in chickpea. Electrolyte and nutrient leakage from the infected plants were used to assess the resistance, tolerance (moderately resistance) and susceptibility of the plants to the infection. Based on the results, both the pigeon pea cultivars (Maruti and PT-221) were rated as resistant, and ICCV-10 was rated as a tolerant cultivar of chickpea. However, chickpea cultivar L −550 was found to be a susceptible host for infection by Fusarium delphinoides. These results suggest that Fusarium delphinoides, which belongs to the Fusarium dimerum species group, is an IAA producing plant pathogen and causes wilt in chickpea. Further, along with pathogenicity tests, electrolyte and nutrient leakage analysis can be used to assess the pathogenicity of pathogenic fungi.

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Section: Discussionmentioning

confidence: 99%

Pathogenicity of indole-3-acetic acid producing fungus Fusarium delphinoides strain GPK towards chickpea and pigeon pea

2011

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“…The most commonly observed effect in root infection is the loss of electrolytes due to the disruption of the cell membrane, which may occur via pathogen enzymes or toxins and often leads to a dramatic increase in ion movement especially K + and H + through the cell membrane (Agrios, 1997). The quantification of cell and tissue electrolyte leakage was used reliably to screen avocado rootstocks for resistance to Phytophthora root rot (Zilberstein and Pinkas, 1987). This technique was also employed to compare and identify disease‐tolerant and susceptible citrus plants infected with two Phytophthora species (Widmer et al., 1998).…”

Section: Discussionmentioning

confidence: 99%

Peroxidase Activity, Isozyme Patterns and Electrolyte Leakage in Roots of Cocoyam Infected with Pythium myriotylum

Nyochembeng¹,

Beyl²,

Pacumbaba³

2007

Journal of Phytopathology

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Knowledge of host defence response in cocoyam against Pythium myriotylum is essential in understanding disease resistance and the development of effective control measures for the cocoyam root rot disease. Four cocoyam accessions were assessed for root rot disease reaction by inoculating the roots of intact plants in the greenhouse and detached roots in the laboratory with P. myriotylum isolate ÔMamuÕ from Cameroon. Electrolyte leakage in detached infected roots and peroxidase activities and isozyme expressions in crude protein extracts collected from healthy roots of inoculated and non-inoculated plants at 0, 2, 4, 6 and 8 days post inoculation (dpi) were used independently to assess resistance/tolerance. Based on the results, cocoyam accessions RO1054 and RO3015 were rated tolerant/moderately resistant while accessions RO2063 and ÔLocal WhiteÕ (LW) were rated susceptible to P. myriotylum isolate ÔMamuÕ. The time-course spectrophotometric analysis of peroxidase activity showed an increase in activity in the roots of the tolerant RO1054, 8 days after inoculation. One peroxidase isoform (Rf 0.66) was induced only in roots of the susceptible inoculated accessions ÔLocal WhiteÕ and R02063 at 4 and 6 dpi. One acidic peroxidase isozyme (pI 4.5) and one basic isozyme (pI 7.4) were detected only in roots of inoculated plants. Our results suggest that electrolyte leakage in infected roots can be used to assess tolerance/susceptibility in cocoyam and that tolerance to the root rot disease in cocoyam may be associated in part with an increased generation of peroxidase activity in the roots.

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“…A high variability in laboratory conditions for obtaining Zs from Pc mycelium and in plant inoculations conditions was found. The two main protocols used involve inoculations of cut leaves, roots, shoots or explants with mycelial fragments or culture ltrates [53][54][55] . Assays on cut plants are of particular commercial importance because of the high incidence of Pc in owering ornamental plants 53,[56][57][58] .…”

Section: Introductionmentioning

confidence: 99%

An improved method to study Phytophthora cinnamomi Rands zoospores interactions with host

Lucía,

Serine,

Noelia

et al. 2024

Preprint

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The pathogen Phytophthora cinnamomi Rands (Pc) is one of the ten most widespread phytopathogens in the world causing crown rot, canker and root rot in multi-functional land plants. Pc has a disastrous impact on the surrounding environment and biodiversity of flora, fauna and soil. Pc infects more than 5,000 species, including Quercus suber, Quercus ilex, Castanea sativa, Eucalyptus globulus, Persea americana (avocado), Zea mays (maize) and Solanum lycopersicon (tomato). The efficient spread of Pc depends on the short survival of asexually motile zoospores (Zs), which move through water currents until they penetrate the host roots. Due to the complexity of the life cycle, the management of Zs in the laboratory has remained quite complex for decades. The production of Zs requires mimicking nature by following a complex protocol of circular steps of growth, drought and flooding. Similar to other pathogens, the artificial growth conditions induce a rapid loss of virulence, making it necessary to add additional steps of plant infection in between these other steps. In this work, the study of the survival of Zs under different conditions has allowed us to obtain a "ready-to-use" stable stock of Zs with a high capacity to infect the host by direct freezing in liquid nitrogen. Obtaining this stock prevents the loss of virulence of Pc between cultures, thus greatly simplifying the process of inoculating plants and studying Pc with their host.

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Detached Root Inoculation -- A New Method to Evaluate Resistance to Phytophthora Root Rot in Avocado Trees

Cited by 10 publications

References 0 publications

Pathogenicity of indole-3-acetic acid producing fungus Fusarium delphinoides strain GPK towards chickpea and pigeon pea

Pathogenicity of indole-3-acetic acid producing fungus Fusarium delphinoides strain GPK towards chickpea and pigeon pea

Peroxidase Activity, Isozyme Patterns and Electrolyte Leakage in Roots of Cocoyam Infected with Pythium myriotylum

An improved method to study Phytophthora cinnamomi Rands zoospores interactions with host

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