Additional Sources of Resistance to Tan Spot of Wheat

Autor: S. W. Meinhardt, L. J. Francl, James A. Anderson, C. R. Riede, James G. Jordahl
Rok vydání: 1996
Předmět:
Zdroj: Crop Science. 36:771-777
ISSN: 1435-0653
0011-183X
DOI: 10.2135/cropsci1996.0011183x003600030040x
Popis: Tan spot, a foliar disease of wheat (Triticum aestivum L. em Thell) and durum (T. turgidum var. durum L.) caused by Pyrenophora triticirepentis (Died.) Drechs., reduces yield in susceptible cultivars by 3 to 50%. Additional sources for resistance to tan spot were sought in germplasm consisting of a collection of spring wheats previously screened for reaction to spot blotch [Cochliobolus sativus (Ito & Kurib.) Drech. ex Dastur] in Brazil, wheat cultivars recommended for cultivation in the state of Parana, Brazil, and a collection of synthetic hexaploid wheats. Plants from each of the three groups were inoculated at the seedling stage with a composite of four fungal isolates and at the adult stage with one of the four isolates. A subset of germplasm was treated at the seedling stage with necrosis toxin, crude extract, and conidia produced by P. tritici-repentis isolate 86-124. Adult disease reactions did not always agree with seedling evaluations and some of the variation could be explained by sensitivity or a mixed reaction to necrosis toxin. Assay with purified necrosis toxin was a reliable way to detect a major factor involved in resistance. This work identifies diverse germplasm available for incorporation of tan spot resistance into cultivated wheats.
Databáze: OpenAIRE
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