Cereal cultivars can be ranked consistently for resistance to root-lesion nematodes (Pratylenchus thornei & P. neglectus) using diverse procedures

2014 ◽  
Vol 44 (2) ◽  
pp. 175-182 ◽  
Author(s):  
J. G. Sheedy ◽  
A. C. McKay ◽  
J. Lewis ◽  
V. A. Vanstone ◽  
S. Fletcher ◽  
...  
Keyword(s):  
Pratylenchus Thornei ◽  
Lesion Nematodes ◽  
Root Lesion Nematodes ◽  
Cereal Cultivars

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

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.

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.

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