Effect of tuber-borne micro-organisms on hatching activity of potato root leachate towards potato cyst nematodes

Nematology ◽  
2003 ◽  
Vol 5 (1) ◽  
pp. 55-63 ◽  
Author(s):  
N. Aileen Ryan ◽  
Peter Jones

AbstractPotato cyst nematodes hatch in response to hatching factors (HF) present in potato root leachate (PRL). The much higher spontaneous hatch (hatch in the absence of potato plants or PRL) of both Globodera rostochiensis and Globodera pallida in sand (32.2 and 21.1%, respectively) compared to in vitro (6.0 and 4.8%) experiments suggested the presence of other hatching factor-producing organisms in the non-sterile sand. When sterile PRL (from aseptically cultured microplants) and non-sterile PRL (from aseptically cultured microplants grown in the presence of tuber washings) samples were collected and assayed for hatching activity, the in vitro hatch of both PCN species but particularly of G. pallida was greater in non-sterile PRL. When these samples were fractionated on Sephadex G-10 by low pressure liquid chromatography and the fractions tested for hatching activity, the non-sterile PRL produced more hatching factors (HF) than the sterile PRL; in the fractionated sterile PRL only one significant HF (active towards G. pallida) was observed, compared to six (towards G. pallida) and three (towards G. rostochiensis) HF from the non-sterile PRL, with two HF being active towards both species. The non-sterile PRL appeared to produce more hatching factor stimulants (HS) and fewer hatch inhibitors (HI) than the sterile PRL. These results suggest that soil micro-organisms play an important role in the production of hatching chemicals and it is proposed that the differences in HF profiles between sterile and non-sterile PRL were due, at least in part, to increased HS production in the non-sterile PRL.

Nematology ◽  
2004 ◽  
Vol 6 (3) ◽  
pp. 335-342 ◽  
Author(s):  
Aileen Ryan ◽  
Peter Jones

AbstractComparison of potato root leachates (PRL) collected from the roots of mycorrhizal (using the mixed-isolate inoculum, Vaminoc) and non-mycorrhizal potato cv. Golden Wonder confirmed that mycorrhization caused a significant increase in hatching activity towards Globodera pallida but not G. rostochiensis. After fractionating the leachates by low pressure molecular exclusion/anion exchange liquid chromatography, several potato cyst nematode (PCN) species-specific hatching factors (HF) were found only in PRL from mycorrhizal plants. Leachate from mycorrhizal plants also contained more of several of those HF common to PRL from both mycorrhizal and non-mycorrhizal plants. Significantly more hatching factor stimulants (HS) active towards both PCN species were found in the PRL from mycorrhizal than from non-mycorrhizal plants; several HS were specific to mycorrhizal plants. No differences (quantitative or qualitative) were observed in hatching inhibitor (HI) levels between PRL from mycorrhizal and non-mycorrhizal plants. Mycorrhization of potato plants resulted in a 20% increase in carbon but a 48% decrease in nitrogen concentrations of the PRL compared to that from the non-mycorrhizal plants.


2011 ◽  
Vol 50 (No. 2) ◽  
pp. 70-74 ◽  
Author(s):  
P. Sedlák ◽  
M. Melounová ◽  
S. Skupinová ◽  
P. Vejl ◽  
J. Domkářová

Potato cyst nematodes (PCN) are the big problem in worldwide planting of potatoes and another Solanaceous plants. Identification of individual pathotypes according to international scheme is very demanding but a very important part of the phytosanitary process to control these pests. Molecular genetic identification of different plant and animal species or individuals is a very interesting way at the present time and let’s hope that it will be important in future. This report presents results of the RAPD study of nine different real PCN populations. There were five Globodera rostochiensis populations and four G. pallida populations. Pathotypes Ro2, Ro2/3, Ro4, Ro5, Pa2 and Pa3 were from European populations; population Ro1 and X were of Czech provenance. Genetics variable of these populations was described by a set of six decameric primers (OPA 07, OPG 03, OPG 05, OPG 08, OPG 10 and OPG 13). Genetic dissimilarity was by Gel Manager for Windows evaluated. Detectable differences behind all populations were found and the dendrogram was compiled. The unknown population X was sorted into group of Globodera pallida species subgroup of Pa2 consequently.


2010 ◽  
Vol 46 (No. 4) ◽  
pp. 171-180 ◽  
Author(s):  
O. Douda ◽  
M. Zouhar ◽  
E. Nováková ◽  
J. Mazáková ◽  
P. Ryšánek

Potato cyst nematodes (Globodera rostochiensis, Globodera pallida) remain a key pest in the main potato growing regions of the Czech Republic. Due to difficult direct management and presence of diverse pathotypes attacking different potato cultivars the rapid and reliable diagnostics is of crucial importance. Currently, efforts are aimed at a description of different pathotypes based on DNA analysis. The main objective of this study was to evaluate the homogeneity of sequences of D2/D3 segments of the 28S rDNA gene obtained from 3 populations of G. rostochiensis and 5 populations of G. pallida and estimate their value for diagnostic purposes. PCR amplification yielded a single fragment of the length of 700 bp approximately in all populations. The alignment score of the vast majority of all pair comparisons of G. rostochiensis and G. pallida populations varied from 98 to 99. In total 14 point deletions and 3 substitutions were observed. The variability of D2/D3 segments of potato cyst nematodes is rather low and this DNA region can be used for diagnostics on a species level because more differences were found after comparing with G. tabacum and G. millefolii sequences obtained from Gene Bank; however the applicability of D2/D3 sequences to routine diagnostics of potato cyst nematodes could be complicated by its similarity to corresponding sequences of the nematode G. artemisiae.


Nematology ◽  
2015 ◽  
Vol 17 (9) ◽  
pp. 1105-1111 ◽  
Author(s):  
Vincas Būda ◽  
Rasa Čepulytė-Rakauskienė

Two behavioural assays were carried out: one on the attraction of potato cyst nematodes (PCN), Globodera rostochiensis and G. pallida, to solanaceae-specific secondary metabolite α-solanine, the other on the effect of ZnSO4 (a compound known to suppress chemoreceptors). The first assay demonstrated that α-solanine was attractive to second-stage juveniles (J2) of PCN; G. pallida was attracted to concentrations of 10−4 M and 10−5 M, whereas G. rostochiensis was attracted to 10−5 M. Globodera pallida reacted faster than G. rostochiensis to the same concentration of α-solanine. As α-solanine is produced by host plants of PCN, this compound is attributed to kairomones. The response to α-solanine of nematodes pre-exposed to a 3 mM ZnSO4 solution was significantly suppressed compared to that of water control. The effect was observed throughout the whole testing period (30 min). This is the first evidence that both α-solanine and ZnSO4 can affect the behaviour of hatched J2 of PCN.


Parasitology ◽  
1985 ◽  
Vol 91 (3) ◽  
pp. 499-506 ◽  
Author(s):  
P. C. Fox ◽  
H. J. Atkinson

SUMMARYA total of 65 enzymes in the 8 European pathotypes of the potato cyst nematodes Globodera pallida and G. rostochiensis were examined by isoelectric focusing (IEF) for possible polymorphic variants which may aid rapid pathotype recognition. Quantitative variation was seen with glucose oxidase (EC 1.1.3.4), with high levels of this enzyme present in G. rostochiensis Ro3. Mannose phosphate isomerase (EC 5.3.1.8) also varied between the pathotypes with G. rostochiensis Ro4 and Ro5 differing from the other pathotypes in the relative absorbance of some bands. Phosphoglucomutase was examined on a narrow-range pH gel and additional differences to those described previously were detected.


Nematology ◽  
2007 ◽  
Vol 9 (5) ◽  
pp. 719-729 ◽  
Author(s):  
Patrick Haydock ◽  
Peter Jones ◽  
Ken Devine ◽  
Thomas Deliopoulos

AbstractSuccessful mycorrhization of potato plants cv. Golden Wonder was achieved with three commercial preparations of arbuscular mycorrhizal fungi (AMF): Vaminoc (mixed-isolate inoculum) and two of its components, Glomus intraradices and Glomus mosseae. Potato cyst nematode hatching assays were conducted on the potato root leachate (PRL) produced by inoculated and non-inoculated potato plants to examine the effect of AMF inoculation on the hatching response of the two PCN species, Globodera rostochiensis and G. pallida. The overall hatch response of G. rostochiensis to the potato root leachate was greater than G. pallida. Root leachates from Vaminoc- and G. mosseae-inoculated plants were found to stimulate the hatch of G. pallida in the first 3 weeks after shoot emergence. Fractionation of root leachates with standardised carbon content by Sephadex G-10 chromatography revealed multiple AMF effects on hatching factor (HF) production. Root leachates from Vaminoc-inoculated plants contained markedly more G. pallida-active HF than all other treatments; by contrast, PRL from the three AMF treatments exhibited little variation in the quantity of G. rostochiensis-active HF produced. Several HF were PCN species-specific or species-selective, with those resolved from the G. intraradices and G. mosseae PRL profiles exhibiting an apparent preference for G. rostochiensis rather than G. pallida. Mycorrhization also significantly increased the root dry weight of plants.


Nematology ◽  
2009 ◽  
Vol 11 (5) ◽  
pp. 749-756 ◽  
Author(s):  
Susan J. Turner ◽  
Colin C. Fleming ◽  
Brendan P. Moreland ◽  
Trevor J.G. Martin

Abstract Potato cyst nematodes (PCN) hatch in response to the presence of root diffusate produced by host plants. Potato root diffusate (PRD) contains hatching factors that stimulate differential hatch between the two PCN species (Globodera rostochiensis and G. pallida) throughout the growing season. In order to clarify the role of PRD in wild potato clones resistant to PCN, a series of trials established optimal test conditions using a range of PCN populations on a representation of Solanum species (Solanum sanctae-rosae, S. sparsipilum, S. gourlayi, S. acaule, S. oplocense). Dilution tests showed that half strength PRD consistently stimulated highest levels of nematode hatch. PCN populations were treated with PRD collected weekly throughout the trials, mimicking the natural release of chemical stimulants from growing potato roots. Whilst the G. rostochiensis Ro1 population showed no variation in hatch, other populations displayed differences in hatch in the presence of the different Solanum PRD. This may reflect the different coevolutionary histories of nematodes and their Solanum hosts in South America.


Nematology ◽  
2016 ◽  
Vol 18 (7) ◽  
pp. 803-810 ◽  
Author(s):  
Eoin P. Lettice ◽  
Peter W. Jones

Soil samples taken from the ridge of field-grown potato (cv. British Queen) as well as from bulk soil of the same field were incubated with sterile potato root leachate or water. Samples were filtered and filtrates used in anin vitrobioassay to determine their effect on hatch of potato cyst nematodes (PCN)Globodera rostochiensisandG. pallida. Concurrently, an experiment was established where the sterile potato root leachate or water was incubated with a sterile soil wash. Ridge soil was shown to induce significantly more hatching than bulk soil, indicating the presence of PCN hatching factors. When a soil wash of ridge soil was used it did not increase hatch, suggesting a role for soil microorganisms in the hatching process. Greater hatch ofG. rostochiensisin bulk soil compared toG. pallidasuggests a role for soil microorganisms in spontaneous hatch of PCNin vivo.


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