Morphological Diagnosis of Heterodera avenae in Iraq and Their Pathogenicity on Three Wheat Varieties

Abstract Wheat is one of the dominant crops in many countries being used by human and livestock. Cereal Cyst nematodes one of very important pest that reduce yield up to 50% worldwide. In this study, the survey was conducted across seven Governorate the Heterodera type appeared in three of them (Misan, Baghdad, Al-Najaf) chosen based from their wide area of small grain production and geographical position in 2020. Cyst were identified by morphological methods. Species identification has been validated by molecular method. As a result of the study, that the wheat variety Buhooth 22 was less affected by the infection and the infection rate was 40% and a significant difference was recorded between it and the other two varieties, Ibaa 99 and Rashid. The infection rate was high and reached 53.3 and 60% respectively. This is first study in Iraq in terms of morphometric nematode identification in case of Cyst nematodes. These results can be of signifigance for improving strategies to control Cereal Cyst nematode affecting wheat production in Iraq.