PLANT CELL BIOTECHNOLOGY AND MOLECULAR BIOLOGY

Wheat is the third most cultivated cereal crop after maize and rice in the grass family Poaceae. In Iraq, seed decay and damping-off is one of the diseases affecting the quality and yield of the wheat crop annually. This disease has been caused by several pathogens, including species of the Fusarium genus. This study was accomplished to survey and identify molecularly the causal agents associated with this disease observed in wheat fields of Kerbala Province. Ninety-three fungal isolates were obtained from twenty-three wheat fields distributed in Karbala province during 2018-2019 season. The results of morphological and molecular analysis have shown that these isolates belonged to seven species of Fusarium genus: F. solani, F. graminearum, F. oxysporum, F. chlamydosporum, F. culmorum, F. falciforme, and F. cerealis. The most common species was F. solani, with percentage 38% followed by F. oxysporum and F. graminearum with percentages 22 and 20%, respectively. Additionally, the disease was prevalent in all inspected fields. However, the highest disease incidences were found in the fields of Al-Husseiniya, Al-Hurr, and Al-Khairat regions at percentages of 19,18 16%, respectively. The results also revealed that all species of Fusarium isolated in this study had a high pathogenic ability on wheat seeds and seedlings. In Iraq, F. solani and F. graminearum were reported previously causing the same disease. However, this is the first report of the rest five Fusarium species as causative agents of seed decay and damping off disease on wheat crop in Karbala province, Iraq.