TY - JOUR
T1 - Insights into tan spot and stem rust resistance and susceptibility by studying the pre-green revolution global collection of wheat
AU - Abdullah, Sidrat
AU - Sehgal, Sunish Kumar
AU - Jin, Yue
AU - Turnipseed, Brent
AU - Ali, Shaukat
N1 - Publisher Copyright:
© The Korean Society of Plant Pathology.
PY - 2017/4
Y1 - 2017/4
N2 - Tan spot (TS), caused by the fungus Pyrenophora tritici-repentis (Died) Drechs, is an important foliar disease of wheat and has become a threat to world wheat production since the 1970s. In this study a globally diverse pre-1940s collection of 247 wheat genotypes was evaluated against Ptr ToxA, P. tritici-repentis race 1, and stem rust to determine if; (i) acquisition of Ptr ToxA by the P. tritici-repentis from Stagonospora nodorum led to increased pathogen virulence or (ii) incorporation of TS susceptibility during development stem rust resistant cultivars led to an increase in TS epidemics globally. Most genotypes were susceptible to stem rust; however, a range of reactions to TS and Ptr ToxA were observed. Four combinations of diseasetoxin reactions were observed among the genotypes; TS susceptible-Ptr ToxA sensitive, TS susceptible-Ptr ToxA insensitive, TS resistant-Ptr ToxA insensitive, and TS resistant-Ptr ToxA toxin sensitive. A weak correlation (r = 0.14 for bread wheat and –0.082 for durum) was observed between stem rust susceptibility and TS resistance. Even though there were no reported epidemics in the pre-1940s, TS sensitive genotypes were widely grown in that period, suggesting that Ptr ToxA may not be an important factor responsible for enhanced prevalence of TS.
AB - Tan spot (TS), caused by the fungus Pyrenophora tritici-repentis (Died) Drechs, is an important foliar disease of wheat and has become a threat to world wheat production since the 1970s. In this study a globally diverse pre-1940s collection of 247 wheat genotypes was evaluated against Ptr ToxA, P. tritici-repentis race 1, and stem rust to determine if; (i) acquisition of Ptr ToxA by the P. tritici-repentis from Stagonospora nodorum led to increased pathogen virulence or (ii) incorporation of TS susceptibility during development stem rust resistant cultivars led to an increase in TS epidemics globally. Most genotypes were susceptible to stem rust; however, a range of reactions to TS and Ptr ToxA were observed. Four combinations of diseasetoxin reactions were observed among the genotypes; TS susceptible-Ptr ToxA sensitive, TS susceptible-Ptr ToxA insensitive, TS resistant-Ptr ToxA insensitive, and TS resistant-Ptr ToxA toxin sensitive. A weak correlation (r = 0.14 for bread wheat and –0.082 for durum) was observed between stem rust susceptibility and TS resistance. Even though there were no reported epidemics in the pre-1940s, TS sensitive genotypes were widely grown in that period, suggesting that Ptr ToxA may not be an important factor responsible for enhanced prevalence of TS.
KW - Foliar disease
KW - Host-selective toxin
KW - Puccinia graminis f. sp. tritici
KW - Wheat
KW - Yellow spot
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U2 - 10.5423/PPJ.OA.07.2016.0157
DO - 10.5423/PPJ.OA.07.2016.0157
M3 - Article
C2 - 28381959
AN - SCOPUS:85016838408
SN - 1598-2254
VL - 33
SP - 125
EP - 132
JO - Plant Pathology Journal
JF - Plant Pathology Journal
IS - 2
ER -