Thermographic medium-far ground-based proximal sensing for in-field wheat Stagonospora nodorum blotch detection

2013 ◽  
Vol 120 (5-6) ◽  
pp. 205-208 ◽  
Author(s):  
Francesca Antonucci ◽  
Paolo Menesatti ◽  
Angela Iori ◽  
Federico Pallottino ◽  
Maria Grazia D’Egidio ◽  
...  
Keyword(s):  
Stagonospora Nodorum ◽  
Proximal Sensing ◽  
Stagonospora Nodorum Blotch ◽  
Blotch Detection

scholarly journals Quantifying the Effects of Wheat Residue on Severity of Stagonospora nodorum Blotch and Yield in Winter Wheat

2015 ◽  
Vol 105 (11) ◽  
pp. 1417-1426 ◽  
Author(s):  
L. K. Mehra ◽  
C. Cowger ◽  
R. Weisz ◽  
P. S. Ojiambo
Keyword(s):  
North Carolina ◽  
Winter Wheat ◽  
Disease Severity ◽  
Block Design ◽  
Soil Surface ◽  
Kernel Weight ◽  
Stagonospora Nodorum ◽  
Wheat Crop ◽  
Stagonospora Nodorum Blotch ◽  
Initial Inoculum

Stagonospora nodorum blotch (SNB), caused by the fungus Parastagonospora nodorum, is a major disease of wheat (Triticum aestivum). Residue from a previously infected wheat crop can be an important source of initial inoculum, but the effects of infected residue on disease severity and yield have not previously been quantified. Experiments were conducted in Raleigh and Salisbury, North Carolina, in 2012, 2013, and 2014 using the moderately susceptible winter wheat cultivar DG Shirley. In 2014, the highly susceptible cultivar DG 9012 was added to the experiment and the study was conducted at an additional site in Tyner, North Carolina. Four (2012) or six (2013 and 2014) wheat residue treatments were applied in the field in a randomized complete block design with five replicates. Treatments in 2012 were 0, 30, 60, and 90% residue coverage of the soil surface, while 10 and 20% residue treatments were added in 2013 and 2014. Across site-years, disease severity ranged from 0 to 50% and increased nonlinearly (P < 0.05) as residue level increased, with a rapid rise to an upper limit and showing little change in severity above 20 to 30% soil surface coverage. Residue coverage had a significant (P < 0.05) effect on disease severity in all site-years. The effect of residue coverage on yield was only significant (P < 0.05) for DG Shirley at Raleigh and Salisbury in 2012 and for DG 9012 at Salisbury in 2014. Similarly, residue coverage significantly (P < 0.05) affected thousand-kernel weight only of DG 9012 in 2014 at Raleigh and Salisbury. Our results showed that when wheat residue was sparse, small additions to residue density produced greater increases in SNB than when residue was abundant. SNB only led to effects on yield and test weight in the most disease-conducive environments, suggesting that the economic threshold for the disease may be higher than previously assumed and warrants review.

scholarly journals Seedling resistance to Stagonospora nodorum blotch in wheat genotypes

2013 ◽  
Vol 49 (No. 2) ◽  
pp. 77-85 ◽  
Author(s):  
M. Cséplö ◽  
M. Csösz ◽  
M. Gál ◽  
O. Veisz ◽  
G. Vida
Keyword(s):  
Stagonospora Nodorum ◽  
Infected Leaf ◽  
Seedling Resistance ◽  
Stagonospora Nodorum Blotch ◽  
Breeding Lines ◽  
Disease Progress Curve ◽  
Disease Progress ◽  
Progress Curve ◽  
Lesion Type ◽  
Set Up

In two independent experiments set up in the greenhouse the seedling resistance to Stagonospora nodorum blotch was investigated in 92 varieties, breeding lines and genotypes with a known genetic background. The greatest area under the disease progress curve calculated from lesion type was 37.06, while in the case of the most resistant genotype this value was 0.38. Many of the lines and varieties bred in Martonv&aacute;s&aacute;r proved to have excellent resistance in terms of both percentage of infected leaf area and lesion type. Observations indicate that, depending on the aim of the experiment, the efficient selection of breeding lines is possible in the seedling stage either on the basis of the area under the disease progress curve calculated for lesion types, or on the basis of lesion types scored 7, 11 or 14 days after inoculation.

scholarly journals Evaluation and Association Mapping of Resistance to Tan Spot and Stagonospora Nodorum Blotch in Adapted Winter Wheat Germplasm

Plant Disease ◽  
2015 ◽  
Vol 99 (10) ◽  
pp. 1333-1341 ◽  
Author(s):  
Zhaohui Liu ◽  
Ibrahim El-Basyoni ◽  
Gayan Kariyawasam ◽  
Guorong Zhang ◽  
Allan Fritz ◽  
...  
Keyword(s):  
United States ◽  
Winter Wheat ◽  
Association Mapping ◽  
Great Plains ◽  
The United States ◽  
Tan Spot ◽  
Stagonospora Nodorum ◽  
Northern Great Plains ◽  
Stagonospora Nodorum Blotch ◽  
Pyrenophora Tritici Repentis

Tan spot and Stagonospora nodorum blotch (SNB), often occurring together, are two economically significant diseases of wheat in the Northern Great Plains of the United States. They are caused by the fungi Pyrenophora tritici-repentis and Parastagonospora nodorum, respectively, both of which produce multiple necrotrophic effectors (NE) to cause disease. In this work, 120 hard red winter wheat (HRWW) cultivars or elite lines, mostly from the United States, were evaluated in the greenhouse for their reactions to the two diseases as well as NE produced by the two pathogens. One P. nodorum isolate (Sn4) and four Pyrenophora tritici-repentis isolates (Pti2, 331-9, DW5, and AR CrossB10) were used separately in the disease evaluations. NE sensitivity evaluation included ToxA, Ptr ToxB, SnTox1, and SnTox3. The numbers of lines that were rated highly resistant to individual isolates ranged from 11 (9%) to 30 (25%) but only six lines (5%) were highly resistant to all isolates, indicating limited sources of resistance to both diseases in the U.S. adapted HRWW germplasm. Sensitivity to ToxA was identified in 83 (69%) of the lines and significantly correlated with disease caused by Sn4 and Pti2, whereas sensitivity to other NE was present at much lower frequency and had no significant association with disease. As expected, association mapping located ToxA and SnTox3 sensitivity to chromosome arm 5BL and 5BS, respectively. A total of 24 potential quantitative trait loci was identified with −log (P value) > 3.0 on 12 chromosomes, some of which are novel. This work provides valuable information and tools for HRWW production and breeding in the Northern Great Plains.

scholarly journals Resistance to Tan Spot and Stagonospora nodorum Blotch in Wheat-Alien Species Derivatives

Plant Disease ◽  
2008 ◽  
Vol 92 (1) ◽  
pp. 150-157 ◽  
Author(s):  
R. E. Oliver ◽  
X. Cai ◽  
R.-C. Wang ◽  
S. S. Xu ◽  
T. L. Friesen
Keyword(s):  
Alien Species ◽  
Resistance Genes ◽  
Wheat Breeding ◽  
Tan Spot ◽  
Stagonospora Nodorum ◽  
Wheat Line ◽  
Stagonospora Nodorum Blotch ◽  
Economical Method ◽  
Pyrenophora Tritici Repentis ◽  
The World

Tan spot (caused by Pyrenophora tritici-repentis) and Stagonospora nodorum blotch (SNB) (caused by Stagonospora nodorum) are destructive fungal diseases of wheat (Triticum aestivum) throughout the world. Host plant resistance is thought to be an efficient and economical method of control. The objective of the present study was to identify novel sources of tan spot and SNB resistance in wheat genotypes derived from the crosses between wheat and alien species. Evaluations were conducted at the seedling stage in a growth chamber with 100% relative humidity. For each genotype, three replications were used for each disease. Among the 199 wheat-alien species derivatives evaluated, 65 exhibited resistance to tan spot and 30 showed resistance to SNB similar to BR34, a Brazilian wheat line used as the resistant control. Eleven derivatives were resistant to both diseases. Reactions of the derivatives and their respective wheat parents to tan spot and SNB suggest that resistance genes in the derivatives are derived from alien species. These derivatives can serve as desirable bridges for introgression of resistance genes from alien species to cultivated wheat, and could contribute novel and effective tan spot and SNB resistance to wheat breeding.

scholarly journals Reevaluation of a Tetraploid Wheat Population Indicates that the Tsn1–ToxA Interaction Is the Only Factor Governing Stagonospora nodorum Blotch Susceptibility

2009 ◽  
Vol 99 (8) ◽  
pp. 906-912 ◽  
Author(s):  
Justin D. Faris ◽  
Timothy L. Friesen
Keyword(s):  
Mapping Population ◽  
Tetraploid Wheat ◽  
Tan Spot ◽  
Stagonospora Nodorum ◽  
Stagonospora Nodorum Blotch ◽  
Wheat Population ◽  
Chromosome 5B ◽  
Study Results ◽  
Trait Locus

The wheat Tsn1 gene on chromosome 5B confers sensitivity to a host-selective toxin produced by the pathogens that cause tan spot and Stagonospora nodorum blotch (SNB) known as Ptr ToxA and SnToxA, respectively (hereafter referred to as ToxA). A compatible Tsn1–ToxA interaction is known to play a major role in conferring susceptibility of hexaploid (common) wheat to SNB. However, a recent study by another group suggested that the Tsn1–ToxA interaction was not relevant in conferring susceptibility of the tetraploid (durum) wheat cv. Langdon (LDN). Here, we reevaluated the role of the Tsn1–ToxA interaction in governing SNB susceptibility using the same mapping population and Stagonospora nodorum isolate (Sn2000) as were used in the previous study. Results of our quantitative trait locus analysis showed that the Tsn1 locus accounted for 95% of the variation in SNB. In addition, inoculation of the mapping population with two ToxA-knockout strains of Sn2000 revealed that the entire population was resistant. Furthermore, several LDN Tsn1-disrupted mutants were evaluated and found to be resistant to SNB. Together, these results prove unequivocally that Tsn1 is the only factor present along chromosome 5B that governs response to SNB in this population and that a compatible Tsn1–ToxA interaction is necessary for the manifestation of disease. Therefore, the results from the previous study are refuted.

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