International Symposium on Cereal Leaf Blights 2019 | University College Dublin, Ireland | 22-24 May 2019

Current Knowledge of tan spot of wheat in Algeria


Hamikda Benslimane*
Ecole Nationale Supérieure d’Agronomie, Département de Botanique, El-Harrach, Alger, Algleria. (2) Institut National de la Recherche Agronomique d’Algérie

Abdelkader Benbelkacem
Institut National de la Recherche Agronomique d’Algérie, Unité de Recherche de Constantine, Station ITGC, Elkhroub, Algérie

Norddine Ouaar
Ecole Nationale Supérieure d’Agronomie, Département de Botanique, El-Harrach, Alger, Algleria. (2) Institut National de la Recherche Agronomique d’Algérie

Amor Yahyaoui *
International Maize and Wheat Improvement Center, Apdo. Postal 6-641, 06600, Mexico DF, Mexico.

Zouaoui Bouznad
Ecole Nationale Supérieure d’Agronomie, Département de Botanique, El-Harrach, Alger, Algleria. (2) Institut National de la Recherche Agronomique d’Algérie

Micheal Baum *
International Center for Agricultural Research in Dry Areas, Morocco


Oral Presentation
Host-Pathogen Interactions

Moore Auditorium, UCD O'Brien centre for Science
23 May 2019, 14:00

View this abstract online by visting isclb2019.com/see/ABS67804

Tan spot, caused by Pyrenophora tritici-repentis, is a serious disease of wheat, in Algeria for a long time. A collection of isolates sampled from several wheat growing areas in Algeria, for several seasons have been studied. They, showed a wide morphologically variation; this includes cultures characters, mycelia grow, sporulation potential and conidia measurements. Races population structure analysis, using a differ­ential host set among which, both bread and durum wheat were included, was performed.  Races 1, 4, 5, 6, 7, and 8 were found and a new virulence pattern was discovered. Isolates with this new pattern induced necrosis in durum wheat but failed to induce any disease in the common wheat genotypes (Glenlea, 6B662 and, 6B665) in the differential set. Molecular characterization showed that isolates of this virulence pattern, harbor ToxA and ToxB genes; sequencing showed that their coding regions are identical to those of functional virulence genes. Amplification of ToxA and ToxB virulence genes showed that the genome of isolates sampled from Algerian field harbored both genes, their distribution through growing wheat areas have been established. Otherwise, fluorescent Amplified Fragment Length Polymorphism (AFLP), revealed high genetic diversity. Cluster analysis of molecular data showed that clustering of the isolates was independent of their race classification, geographic origin, or host plant. However, one isolate that showed a new virulence pattern was clearly distinguished from the rest of the population studied. Using resistant varieties still the best way to overcoming this disease, a seedling reaction of commercial wheat varieties evaluated in controlled conditions, showed that few varieties of durum wheat have an appreciable level of résistance.