Fatima Hassan Abdalhussain Alzajrawy

This was carried out to detect the main bacterial pathogens causing onion rot in storage through hot seasons of 2022-2023 for six onion varieties. The results showed that the highest average of disease index over seasons was 64.28% for white, variety in winter season, the lowest was 16.6 % for the red imported variety in summer season. The disease intensity over seasons showed highest average was 38.32% in summer season for yellow variety, while the lowest average was 3.33% in spring season for of infection severity also revealed that the highest average percentage was in the spring season for the imported red variety. The disease index and disease intensity showed highest average were 40.33, and 26.44% respectively for white local variety, while the lowest average were 3.88, and 6.58% respectively for red imported variety. Six bacterial isolates were selected depending on the highest disease index, and molecularly diagnosed, using polymerase chain reaction (PCR). New bacterial rot disease onion has frequently appeared in many areas of AL-Najaf province -Iraq. The pathogens of the disease was identified six isolates as (Klebsiella pneumoniae, Bacillus safensis, and Bacillus pumilus) which known to cause pulmonary and urinary disease in human and occasionally exist as a harm less entophyte in plants. To evaluate the pathogenicity, we inoculated onion bulbs. The finding serve as an alert to plant. The onion plants in the storage could serve as a reservoir for K. pneumoniae, B. safensis, and B. pumilus. Which might infect human or animals when conditions are favorable. The new finding not only significant in the developing control strategy for the new disease in Iraq, but also serve as starting point for further studies on the harm less of these bacteria in humans and animals.

This study was conducted at the laboratories of the College of Agriculture/Plant Protection Department at the University of Kufa according to a completely randomized design (CRD) to determine the extent of the effect of the alcoholic extract (Cinnamonum zeylanicum, Cissus rhombifolia) and ZnONPs at concentrations 10, 20 and 30% for each plant on the genus of bacteria Klebseilla pneumoniae. The results showed that the alcoholic extracts and ZnONPs gave a high efficiency in inhibiting bacteria for the studied traits minimum inhibitory concentration test 30% concentration of the alcoholic cinnamon extract and ZnONPs of the study gave a high inhibitory ability compared to the rest of the concentrations, as it was found that the inhibitory ability of the extract, increases with increasing concentration.