Relationship between root lesion nematodes (Pratylenchus neglectus and P. thornei) and performance of wheat varieties

1998 ◽  
Vol 38 (2) ◽  
pp. 181 ◽  
Author(s):  
V. A. Vanstone ◽  
A. J. Rathjen ◽  
A. H. Ware ◽  
R. D. Wheeler
Keyword(s):  
Wheat Yield ◽  
South Australia ◽  
Nematode Species ◽  
Significant Negative Correlation ◽  
Limiting Factors ◽  
Wheat Varieties ◽  
Pratylenchus Neglectus ◽  
Lesion Nematodes ◽  
Root Lesion Nematodes ◽  
The Relationship

Summary. The root lesion nematodes Pratylenchus neglectus andP. thornei occur throughout the cereal cropping areas of South Australia. In 1996, field trials on the Eyre Peninsula of South Australia were assessed to determine the relationship between density of nematodes within field plots in early October and harvested grain yield of 9 wheat varieties. The Pratylenchus species present was either P. neglectus (at Streaky Bay, Minnipa and Kalanbi) or P. thornei (at Nunjikompita). Absence of other major yield limiting factors at these sites in 1996 enabled determination of the relationship between nematode population and wheat yield. There was a significant, negative correlation between mean yield and nematode populations for the 9 varieties at 3 of the sites (P<0.01 for Streaky Bay and Nunjikompita; P<0.05 for Minnipa). Root lesion nematodes were responsible for 56–74% of the observed varietal differences in yield at these sites. The tolerant variety Excalibur yielded 19% (Streaky Bay), 23% (Minnipa) or 33% (Nunjikompita) more than the intolerant variety Spear, and Excalibur resulted in 69, 63 or 66% fewer nematodes, respectively, than in plots of Spear. Although nematode populations could not be assessed at the Kalanbi site, varietal yield relations were similar to the other sites, with Excalibur yielding 18% more than Spear. The 9 varieties were ranked for both resistance and tolerance to the 2 nematode species.

Measuring yield loss in cereals caused by root lesion nematodes (Pratylenchus neglectus and P. thornei) with and without nematicide

1999 ◽  
Vol 50 (4) ◽  
pp. 617 ◽  
Author(s):  
S. P. Taylor ◽  
V. A. Vanstone ◽  
A. H. Ware ◽  
A. C. McKay ◽  
D. Szot ◽  
...  
Keyword(s):  
Negative Correlation ◽  
Yield Loss ◽  
Wheat Variety ◽  
Significant Negative Correlation ◽  
Multiplication Rate ◽  
Nematode Density ◽  
Wheat Varieties ◽  
Pratylenchus Neglectus ◽  
Lesion Nematodes ◽  
Root Lesion Nematodes

Yield loss caused by root lesion nematodes (Pratylenchus neglectus and P. thornei) was measured using the nematicide aldicarb (Temik 150GTM) or by correlating yield with initial or final nematode densities. In 1996, rotation trials (1 P. neglectus and 1 P. thornei) were established with susceptible and moderately resistant wheat varieties and resistant barley and triticale varieties. An intolerant oat variety (cv. Echidna) was planted over all plots in 1997. Nematode densities were 90% (P. neglectus) or 95% (P. thornei) lower in oat plots following the resistant triticale (cv. Tahara) relative to the susceptible wheat (cv. Machete). In 1997, a significant, negative correlation between both initial and final nematode density and yield was obtained. In wheat variety trials (3 sites) in 1997, a significant, negative correlation was also obtained between mean variety yield and mean final P. neglectus density or mean P. neglectus multiplication rate. Yield loss of up to 20% was calculated from the regression. In all trials, cereal varieties that were more resistant were also more tolerant. In 1996, aldicarb rate trials (1 P. neglectus and 1 P. thornei) were established to assess the affect of rate and timing of aldicarb application on yield of 2 susceptible/intolerant wheat varieties (cvv. Machete and Janz). Lower rates of aldicarb (≤1.5 kg a.i./ha) gave inconsistent nematode control and did not significantly increase yield. Rates ≥2.5 kg a.i./ha reduced nematode densities by 70–90%, resulting in up to 23% greater yield for Machete. The magnitude of yield loss caused by P. neglectus or P. thornei determined with or without nematicide was similar between trials.

scholarly journals First Report of Pratylenchus neglectus and P. thornei Infecting Canola and Weeds in Iran

Plant Disease ◽  
2006 ◽  
Vol 90 (12) ◽  
pp. 1555-1555 ◽  
Author(s):  
S. Fatemy ◽  
E. Abootorabi ◽  
N. Ebrahimi ◽  
F. Aghabeigi
Keyword(s):  
Nematode Species ◽  
Heterodera Schachtii ◽  
Potential Threat ◽  
Brassica Napus L ◽  
Pratylenchus Neglectus ◽  
First Report ◽  
Winter Canola ◽  
Plastic Bags ◽  
Lesion Nematodes ◽  
Root Lesion Nematodes

Cultivation of canola (Brassica napus L.) is relatively new in Iran. Because nearly 90% of Iran's edible oil is imported, farmers are subsidized and encouraged to grow this crop. Except for the sugar beet cyst nematode, Heterodera schachtii, to which susceptibility of some canola cultivars has been established (1), information on other nematode pests of canola is lacking. During a survey from April—May 2002 and repeated in 2003, soil and root samples of winter canola and weeds were collected at harvest of canola from research stations and farmers' fields in the south, west, and northwest of Tehran Province. Each sample was a composite of 25 roots and 2 kg of soil per hectare, collected from the rhizosphere of canola with a 2.5-cm-diameter soil corer. Samples were put in plastic bags and kept at 5°C until they were processed, within 2 weeks from sampling. Samples were sieved through a 0.840-cm aperture sieveand mixed thoroughly. Nematodes were extracted from subsamples of 5 g of roots and 250 g of soil with a modification of the sugar centrifugal flotation method (2), counted, and identified. Two species of root lesion nematodes, Pratylenchus neglectus and P. thornei, were found. When they were present in the same field, they occurred in the roots of both Regents × Cobra and Orient cultivars. Averages of 28 and 321 P. thornei per gram were found in the roots of cvs. Regents × Cobra and Orient, respectively. Averages of 30, 1,026, 626, and 450 P. neglectus per gram of roots of cvs. Regents × Cobra, Orient, Ocapi, and GLSIO were detected, respectively, in different fields. Heavily infected plants were stunted and had roots with dark lesions, a symptom typical of the attacks by these nematodes. Generally, greater nematode densities were in the roots than in the soil and both nematode species were more abundant in cooler than in warmer areas of the province. Since these nematodes are also severe pests of wheat, which is also grown in the province, they could pose a potential threat to both crops. Weeds that were present in the sampled fields belonged to the botanical families Scrophulariaceae, Gramineae, Euphorbiaceae, Crucifereae, and Compositeae. Between 22 and 1,500 P. thornei and 17 P. neglectus per gram of roots of Crucifereae and 280 P. thornei per gram of roots of Gramineae were found. To our knowledge, this is the first report of lesion nematodes infecting canola plants in Iran. References: (1) S. Fatemy and E. Abootorabi. Nematol. Mediterr. 30:163, 2002. (2) W. R. Jenkins. Plant Dis. Rep. 48:692, 1964.

Pratylenchus penetrans and P. neglectus in tubers of potato (Solanum tuberosum) in Ontario

1991 ◽  
Vol 71 (4) ◽  
pp. 1251-1256 ◽  
Author(s):  
Th. H. A. Olthof ◽  
M. S. Wolynetz
Keyword(s):  
Solanum Tuberosum ◽  
Inner Core ◽  
Pratylenchus Penetrans ◽  
Potato Tubers ◽  
Population Densities ◽  
Pratylenchus Neglectus ◽  
Lesion Nematodes ◽  
Cold Room ◽  
Mist Chamber ◽  
Root Lesion Nematodes

Root-lesion nematodes (Pratylenchus penetrans) were extracted from peels of potato tubers (Solanum tuberosum 'Russet Burbank'). The average number of P. penetrans recovered over a 2-wk period in a mist chamber from four batches of tubers, stored for 3–18 wk at 7 °C in a cold room, ranged from 11 to 1925 nematodes tuber−1. An average of 374 Pratylenchus neglectus tuber−1 were recovered from the peels of potato Norchip, grown in soil containing on average 4370 nematodes kg−1 of soil at harvest, and stored for 19 wk at 7 °C. P. penetrans and P. neglectus were recovered only from the outer layer of potato tubers; none was found in the inner core. Planting halves of tubers containing an average of 1925 P. penetrans tuber−1 into nematode-free soil resulted in soil population densities of 2225 P. penetrans kg−1 of soil and root population densities of 884 nematodes root system−1 after 8 wk in the greenhouse. Although many, if not most, potato fields in southern Ontario are already infested by P. penetrans, these studies have shown that stored, infested tubers can initiate a new infestation. Key words: Peel, potato tuber, Pratylenchus neglectus, Pratylenchus penetrans, root-lesion nematode, Solanum tuberosum

scholarly journals Saccharum spontaneum, a Novel Source of Resistance to Root-Lesion and Root-Knot Nematodes in Sugarcane

Plant Disease ◽  
2019 ◽  
Vol 103 (9) ◽  
pp. 2288-2294
Author(s):  
Shamsul A. Bhuiyan ◽  
Kylie Garlick ◽  
George Piperidis
Keyword(s):  
Nematode Species ◽  
Root Lesion Nematode ◽  
Root Knot Nematode ◽  
Root Knot Nematodes ◽  
Nematode Reproduction ◽  
Final Population ◽  
Lesion Nematodes ◽  
Commercial Cultivars ◽  
Lesion Nematode ◽  
Root Lesion Nematodes

Root-lesion nematode (Pratylenchus zeae) and root-knot nematode (Meloidogyne javanica) are two important pathogens of sugarcane (Saccharum hybrid). No commercial cultivars are resistant to these nematodes in Australia. Twenty accession lines of S. spontaneum, a wild relative of sugarcane, were tested against these two nematode species. S. spontaneum lines were tested twice for resistance to root-lesion nematode and three times for root-knot nematode. Reproduction (final population/starting population) of root-lesion nematodes was significantly lower in 17 of the 20 S. spontaneum accession lines tested in two experiments compared with two commercial cultivars. Four S. spontaneum lines supported a significantly lower number of root-lesion nematodes per gram of root than that of two commercial sugarcane cultivars. Reproduction of root-knot nematodes was significantly lower in 16 S. spontaneum lines compared with two commercial cultivars. Fourteen of the S. spontaneum lines tested supported significantly fewer eggs per gram of root compared with two commercial cultivars. This study showed that S. spontaneum lines possessed resistance for root-lesion and root-knot nematodes. Targeted crossing with commercial hybrid parental lines should be conducted to introduce nematode resistance into sugarcane cultivars for the Australian sugar industry.

POPULATION DENSITIES OF FOUR SPECIES OF ROOT-LESION NEMATODES (Pratylenchus) IN THE OAT CULTIVARS, SAIA AND OAC WOODSTOCK

1989 ◽  
Vol 69 (3) ◽  
pp. 903-905 ◽  
Author(s):  
J. L. TOWNSHEND
Keyword(s):  
Population Density ◽  
Avena Sativa ◽  
Pratylenchus Penetrans ◽  
Population Densities ◽  
Pratylenchus Neglectus ◽  
Lesion Nematodes ◽  
Oat Cultivars ◽  
Root Lesion Nematodes

The population densities of four species of root-lesion nematodes (Pratylenchus) were examined in two cultivars of oat (Avena sativa L.) grown in greenhouse pots. The cultivar Saia harbored fewer P. neglectus and P. penetrans than the cultivar OAC Woodstock, while both cultivars were similar hosts for P. sensillatus. Pratylenchus crenatus did not develop in either cultivar.Key words: Oat, population density, Pratylenchus crenatus, Pratylenchus neglectus, Pratylenchus penetrans, Pratylenchus sensillatus

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.

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.

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