Identification of common root-lesion nematode (Pratylenchus thornei Sher et Allen) loci in bread wheat

Genome ◽  
2006 ◽  
Vol 49 (10) ◽  
pp. 1319-1323 ◽  
Author(s):  
Halil Toktay ◽  
C. Lynne McIntyre ◽  
Julie M. Nicol ◽  
Hakan Ozkan ◽  
Halil I. Elekcioglu
Keyword(s):  
Middle Eastern ◽  
Wheat Yield ◽  
Synthetic Hexaploid Wheat ◽  
Parasitic Nematodes ◽  
Resistance Locus ◽  
Natural Genetic Variation ◽  
Pratylenchus Thornei ◽  
Lesion Nematodes ◽  
Synthetic Hexaploid ◽  
Root Lesion Nematodes

Plant parasitic nematodes are a major biotic cause of wheat-yield loss in temperate wheat-growing regions. A major strategy to develop resistance to root-lesion nematodes (RLNs) in wheat is to assess and then exploit their natural genetic variation. This study examines RLN (Pratylenchus thornei) resistance in 1 Middle Eastern landrace (AUS4930 7.2) and 1 synthetic hexaploid wheat, CROC_1/AE.SQUARROSA (224)//OPATA (CROC), using F2 and F9 populations generated by crossing AUS4930 7.2 and CROC with the susceptible cultivar Pastor, and inoculating these crosses with P. thornei in greenhouse trials. Wheat microsatellite markers linked to previously identified quantitative trait loci (QTLs) for resistance to P. thornei and P. neglectus were used to screen both populations. In the AUS4930 7.2 × Pastor population, resistance loci on chromosomes 1B, 2B, and 6D were detected. Similarly, in the CROC × Pastor population, 2 resistance loci, located on chromosomes 1B and 3B, were identified. Interestingly, a resistance locus located on chromosome 6D was not detected. More detailed mapping is required in these 2 populations, developed using new RLN resistance sources, to determine whether the QTLs identified on these chromosomes are the same, are allelic, or are linked to different resistance loci from those previously identified, and to determine whether these 2 sources contain other novel resistance loci.

Resistance to root-lesion nematodes (Pratylenchus thornei and P. neglectus) in synthetic hexaploid wheats and their durum and Aegilops tauschii parents

2008 ◽  
Vol 59 (5) ◽  
pp. 432 ◽  
Author(s):  
J. P. Thompson
Keyword(s):  
Bread Wheat ◽  
Combining Ability ◽  
Aegilops Tauschii ◽  
General Combining Ability ◽  
F1 Hybrids ◽  
Pratylenchus Thornei ◽  
Lesion Nematodes ◽  
Synthetic Hexaploid Wheats ◽  
Synthetic Hexaploid ◽  
Root Lesion Nematodes

Root-lesion nematodes (Pratylenchus thornei Sher and Allen and P. neglectus (Rensch) Filipijev and Schuurmans Stekhoven) cause substantial yield loss to wheat crops in the northern grain region of Australia. Resistance to P. thornei for use in wheat breeding programs was sought among synthetic hexaploid wheats (2n = 6x = 42, AABBDD) produced through hybridisations of Triticum turgidum L. subsp. durum (Desf.) Husn (2n = 4x = 28, AABB) with Aegilops tauschii Coss. (2n = 2x = 14, DD). Resistance was determined for the synthetic hexaploid wheats and their durum and Ae. tauschii parents from the numbers of nematodes in the roots of plants grown for 16 weeks in pots of pasteurised soil inoculated with P. thornei. Fifty-nine (32%) of 186 accessions of synthetic hexaploid wheats had lower numbers of nematodes than Gatcher Selection 50a (GS50a), a partially resistant bread wheat. Greater frequencies of partial resistance were present in the durum parents (72% of 39 lines having lower nematode numbers than GS50a) and in the Ae. tauschii parents (55% of 53 lines). The 59 synthetic hexaploids were re-tested in a second experiment along with their parents. In a third experiment, 11 resistant synthetic hexaploid wheats and their F1 hybrids with Janz, a susceptible bread wheat, were tested and the F1s were found to give nematode counts intermediate between the respective two parents. Synthetic hexaploid wheats with higher levels of resistance resulted from hybridisations where both the durum and Ae. tauschii parents were partially resistant, rather than where only one parent was partially resistant. These results suggest that resistance to P. thornei in synthetic hexaploid wheats is polygenic, with resistances located both in the D genome from Ae. tauschii and in the A and/or B genomes from durum. Five synthetic hexaploid wheats were selected for further study on the basis of (1) a high level of resistance to P. thornei of the synthetic hexaploid wheats and of both their durum and Ae. tauschii parents, (2) being representative of both Australian and CIMMYT (International Maize and Wheat Improvement Centre) durums, and (3) being representative of the morphological subspecies and varieties of Ae. tauschii. These 5 synthetic hexaploid wheats were also shown to be resistant to P. neglectus, whereas GS50a and 2 P. thornei-resistant derivatives were quite susceptible. Results of P. thornei resistance of F1s and F2s from a half diallel of these 5 synthetic hexaploid wheats, GS50a, and Janz from another study indicate polygenic additive resistance and better general combining ability for the synthetic hexaploid wheats than for GS50a. Published molecular marker studies on a doubled haploid population between the synthetic hexaploid wheat with best general combining ability (CPI133872) and Janz have shown quantitative trait loci for resistance located in all 3 genomes. Synthetic hexaploid wheats offer a convenient way of introgressing new resistances to P. thornei and P. neglectus from both durum and Ae. tauschii into commercial bread wheats.

scholarly journals Expression of Oryzacystatin I and II in Alfalfa Increases Resistance to the Root-Lesion Nematode

2003 ◽  
Vol 93 (7) ◽  
pp. 799-804 ◽  
Author(s):  
Deborah A. Samac ◽  
Ann C. Smigocki
Keyword(s):  
Vascular Tissue ◽  
Gus Expression ◽  
Parasitic Nematodes ◽  
Control Line ◽  
Cysteine Proteinases ◽  
Root Lesion Nematode ◽  
Mesophyll Cells ◽  
Lesion Nematodes ◽  
Lesion Nematode ◽  
Root Lesion Nematodes

Digestive cysteine proteinases have been isolated from plant-parasitic nematodes as well as coleopteran and hemipteran insects. Phytocystatins, inhibitors of cysteine proteinases, are found in a number of plants where they may play a role in defense against pathogens and pests. The cDNAs of the phytocystatins from rice, oryzacystatin I (OC-I) and oryzacystatin II (OC-II), were expressed in alfalfa (Medicago sativa) plants under the control of the potato protease inhibitor II (PinII) promoter and the plants were evaluated for resistance to the root-lesion nematode (Pratylenchus penetrans). A PinII-β-glucuronidase (GUS) gene was introduced into alfalfa to determine the pattern of gene expression from this promoter. Constitutive GUS expression was observed in leaf and root vascular tissue, and in some plants, expression was observed in leaf mesophyll cells. Mechanical wounding of leaves increased GUS expression approximately twofold over 24 h. Inoculation with root-lesion nematodes resulted in localized GUS expression. Populations of root-lesion nematodes in alfalfa roots from one line containing the PinII::OC-I transgene and one line containing the PinII::OC-II transgene were reduced 29 and 32%, respectively, compared with a transgenic control line. These results suggest that oryzacystatins have the potential to confer increased resistance to the root-lesion nematode in alfalfa.

Identification and mapping of PmSE5785, a new recessive powdery mildew resistance locus, in synthetic hexaploid wheat

Euphytica ◽  
2015 ◽  
Vol 207 (3) ◽  
pp. 619-626 ◽  
Author(s):  
Yajuan Wang ◽  
Changyou Wang ◽  
Wei Quan ◽  
Xiujuan Jia ◽  
Ying Fu ◽  
...  
Keyword(s):  
Powdery Mildew ◽  
Hexaploid Wheat ◽  
Powdery Mildew Resistance ◽  
Synthetic Hexaploid Wheat ◽  
Resistance Locus ◽  
Mildew Resistance ◽  
Synthetic Hexaploid

scholarly journals Comparing the efficiency of six common methods for DNA extraction from root-lesion nematodes (Pratylenchus spp.)

Nematology ◽  
2020 ◽  
pp. 1-9
Author(s):  
Valeria Orlando ◽  
Simon G. Edwards ◽  
Roy Neilson ◽  
Tom Prior ◽  
David Roberts ◽  
...  
Keyword(s):  
Dna Extraction ◽  
Crop Yields ◽  
Low Cost ◽  
Dna Amplification ◽  
Extraction Methods ◽  
Parasitic Nematodes ◽  
Potential Threat ◽  
Accurate Identification ◽  
Lesion Nematodes ◽  
Root Lesion Nematodes

Summary Robust and accurate identification of root-lesion nematodes (Pratylenchus spp.) is an essential step for determining their potential threat to crop yields and, consequently, development of an efficient agronomic management strategy. It is recognised that DNA-based techniques provide rapid identification of a range of plant-parasitic nematodes including Pratylenchus spp. Efficient and repeatable DNA extraction is central to molecular methodologies. Here, six common DNA extraction protocols were compared to evaluate their efficiency to obtain quality DNA samples for Pratylenchus penetrans. Samples with five and ten individuals of P. penetrans were successfully extracted and amplified by all extraction methods tested, whereas samples with a single nematode presented challenges for DNA amplification. Among all methods tested, the DNA extraction protocol with glass beads proved to be efficient for P. penetrans and all other species tested (P. crenatus, P. neglectus and P. thornei), generating high quality DNA at comparatively low cost and with a rapid sample throughput.

Yield of `Superior' Potatoes following Nematode-suppressive Cover Crops

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 525a-525
Author(s):  
Alan W. McKeown ◽  
J.W. Potter
Keyword(s):  
Cover Crops ◽  
Management Practices ◽  
Soil Management ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Marketable Yield ◽  
Lesion Nematodes ◽  
Series Of Experiments ◽  
Early Dying ◽  
Root Lesion Nematodes

`Superior', the common early potato in Ontario, has developed early dying and low yield problems along the Lake Erie Counties. A series of experiments were planted in 1993 to 1996 to evaluate nematode-suppressive cover crops as a means of soil management, improving yield of potatoes, and reduction of plant parasitic nematodes. Sorghum NK557 as a nematode host, reported suppressive species Sordan 79, Trudan 8 sorghum-sudan hybrids, Domo and Cutlass mustard, Forge canola, and `Norlee' flax were compared to either Telone IIB or Vorlex-Cp (225 L/ha) fumigants applied with a deep shank applicator to 30 cm. Fertility and pest management practices followed Ontario recommendations. Northern root lesion nematodes, Pratylenchus pentrans Cobb, populations were monitored prior to planting potatoes, during the season, and after harvest. Fumigation resulted in the highest total yields in all 3 years and marketable yield in 1994 and 1995. There was no difference in marketable yield in 1996. Yield was similar among cover crops treatments. Suppressive crops, while useful in soil management, were not as effective as fumigants.

Hybridisation of Australian chickpea cultivars with wild Cicer spp. increases resistance to root-lesion nematodes (Pratylenchus thornei and P. neglectus)

2011 ◽  
Vol 40 (6) ◽  
pp. 601-611 ◽  
Author(s):  
John P. Thompson ◽  
Roslyn A. Reen ◽  
Timothy G. Clewett ◽  
Jason G. Sheedy ◽  
Alison M. Kelly ◽  
...  
Keyword(s):  
Pratylenchus Thornei ◽  
Lesion Nematodes ◽  
Root Lesion Nematodes ◽  
Chickpea Cultivars

scholarly journals Survey of Plant-Parasitic Nematodes in Kansas and Eastern Colorado Wheat Fields

2014 ◽  
Vol 15 (3) ◽  
pp. 112-117 ◽  
Author(s):  
T. C. Todd ◽  
J. A. Appel ◽  
J. Vogel ◽  
N. A. Tisserat
Keyword(s):  
Great Plains ◽  
Yield Loss ◽  
Parasitic Nematodes ◽  
Plant Parasitic Nematodes ◽  
Population Densities ◽  
Economic Thresholds ◽  
Lesion Nematodes ◽  
Maximum Root ◽  
Root Lesion Nematodes ◽  
Plant Parasitic

Observations on the prevalence and abundance of plant-parasitic nematodes were made from soil and root samples collected from 2,640 wheat fields in Kansas and Colorado during 2007-2010. Stunt nematodes (predominately Merlinius brevidens and Quinisulcius acutus), root-lesion nematodes (predominately Pratylenchus neglectus), and pin nematodes (Paratylenchus projectus) were the most commonly encountered taxa. Maximum soil population densities of 6,520 and 1,880 nematodes/100 cm3 soil were observed for pin and stunt nematodes, respectively, while a maximum root population density of 90,309 nematodes/g dry root was observed for root-lesion nematodes. Lower nematode densities were associated with wheat following corn, grain sorghum, or soybean for pin and stunt nematodes, and with wheat following fallow for root-lesion nematodes. Based on the results of this survey, 6% and 8% of wheat acreage in the central Great Plains are estimated to be at risk for significant (>5%) yield loss due to stunt nematodes and root-lesion nematodes, respectively. The number of fields with high population densities of both stunt and root-lesion nematodes was negligible (1%); therefore, the total wheat acreage with nematode populations above provisional economic thresholds is estimated to be ∼13%. Damage relationships with greater accuracy, precision, and relevance are necessary to establish reliable yield loss estimates for this region. 3 June 2014. 11 August 2014.

scholarly journals Development and Application of a Multiplex qPCR Method for the Simultaneous Detection and Quantification of Pratylenchus alleni and P. penetrans in Quebec, Canada

Plant Disease ◽  
2018 ◽  
Vol 102 (5) ◽  
pp. 970-976 ◽  
Author(s):  
Nathalie Dauphinais ◽  
Myriam Vandal ◽  
Annie-Ève Gagnon ◽  
Guy Bélair ◽  
Pierre-Yves Véronneau ◽  
...  
Keyword(s):  
Quantitative Polymerase Chain Reaction ◽  
Simultaneous Detection ◽  
Positive Control ◽  
Parasitic Nematodes ◽  
Strongly Correlated ◽  
Lesion Nematodes ◽  
Wide Range ◽  
Root Lesion Nematodes ◽  
Single Larva ◽  
Detection And Quantification

Root lesion nematodes are very common plant-parasitic nematodes that affect a wide range of plants. More than one species can be found simultaneously in a field, and each has a different impact on crop yield. Unfortunately, identifying them using classical morphometric criteria is very difficult and time consuming. The species Pratylenchus alleni was recently observed for the first time in Canada, associated with severe damage in a soybean field in the province of Quebec. The major species, P. penetrans, is also known to be endemic in Quebec but no data exist on its distribution in field crops. This prompted the development of a multiplex quantitative polymerase chain reaction (PCR) assay for the simultaneous detection and quantification of P. alleni and P. penetrans. The method was found to be specific and sensitive, systematically detecting a single larva in a 100-cm3 soil sample with no cross-amplification with other species, even when they outnumbered the target species. An exogenous internal positive control was included in the test to avoid false negatives due to the presence of PCR inhibitors. This assay was used to study the distribution of P. alleni and P. penetrans in 185 soybean fields in the major soybean-producing areas of Quebec during a 3-year survey. Overall, P. penetrans was found in 42% of the fields, P. alleni in 8%, and both species in 4%. The population density of P. alleni in positive fields was still very low, with only a few larvae detected. However, densities of P. penetrans were much higher: the provincial mean was 51.7 nematodes per 100 cm3 of soil (in positive samples), and 8% of the fields (15 of 185) exceeded the theoretical economic threshold. The presence of P. penetrans was also strongly correlated with soil texture, with lighter soil being the most favorable.

Root-lesion nematode (Pratylenchus thornei) limits response of wheat but not barley to stored soil moisture in the Hermitage long-term tillage experiment

1995 ◽  
Vol 35 (7) ◽  
pp. 1049 ◽  
Author(s):  
JP Thompson ◽  
J Mackenzie ◽  
R Amos
Keyword(s):  
Maximum Yield ◽  
No Tillage ◽  
Root Lesion Nematode ◽  
Wheat Varieties ◽  
Stubble Retention ◽  
Pratylenchus Thornei ◽  
Lesion Nematodes ◽  
Lesion Nematode ◽  
Root Lesion Nematodes

The cumulative effects of factorial treatments of tillage (no tillage, conventional), stubble retention (burnt, retained), and nitrogen fertiliser (0, 23, 69 kg N/ha) on yield of continuous winter cereals and on soil properties have been tested in the Hermitage fallow management experiment since 1969. Despite increased soil water stored from the combination of no tillage and stubble retention, wheat responses to the extra water were disappointing in the first 11 years of the experiment. Soil samples from the experiment were shown to be heavily infested with the root-lesion nematode (Pratylenchus thornei Sher and Allen), and therefore in 1980, the main plots were split for crop (wheat cv. Timgalen, barley cv. Clipper) and nematicide treatment (nil, aldicarb). Barley (maximum yield 3.2 t/ha) tolerated the nematodes and responded in this dry year to the extra stored water accumulated with no tillage and stubble retention, but wheat (maximum yield 1.22 t/ha) did not. Nematicide increased wheat yields by 42%. The results from the changes to the Hermitage experiment in 1980 show the importance of considering root-lesion nematodes in interpreting results from long-term experiments involving wheat and in applying those results to farms. Control of root-lesion nematodes on farms by crop rotation and by growing tolerant and resistant wheat varieties is needed to obtain full yield benefits from improved tillage practices.

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