Microbial diversity of buckwheat rhizosphere in wireworm-infested and non-infested soils using metagenomics
Master ThesisWireworm has become a major problem causing extensive crop loss in many potato production areas in Canada. Wireworm control methods includes the use of chemical pesticides. However, pesticides can affect human health and the environment, and their use has consequently been questioned and prohibited in many countries. Therefore, the use of environmentally friendly plant protection techniques, including crop rotation as an alternative to chemical control measures have been promoted to minimize crop damage. In that context, buckwheat is used as a rotation crop to mitigate wireworm damage in potatoes. But so far, less is known about how buckwheat contributes to mitigate disease. This study was designed in a context of integrated pest management, with primary objectives to:(1) determine the microbial diversity in the buckwheat rhizosphere in comparison with other rotation crops; and (2) determine the correlation between the buckwheat rhizosphere microbiome structure and wireworm density. To achieve these objectives, 16S rRNA metagenomic sequencing was performed to determine the microbial diversity in bulk and rhizosphere soils of buckwheat and barley grown at two locations during two growing seasons. A pilot wireworm trapping study was also performed to assess the wireworm population following buckwheat and barley as rotation crops. The study identified 27 phyla in the two crops of which Proteobacteria, Bacteroidetes, Actinobacteria were the most abundant and species identification was confidently achieved in 7 phyla including Proteobacteria, Actinobacteria, Acidobacteria, Bacteroidetes, Firmicutes, Deinococcus-Thermus and Crenarchaeota. Interestingly, Methylophilus flavus, Saccharopolyspora tripterygii and Deinococcus yunweiensis were three operational taxonomic units (OTUs) found at the species level to be unique to the buckwheat rhizosphere soil at both locations and purported as non-pathogenic entophytic bacteria and beneficial for sustainable agriculture. Moreover, after two years, a reduction in wireworm density was observed in both crops although, the direct link associating the reduced wireworm density and the observed microbial diversity and the operating mechanisms in each crop remain to be elucidated. Taken together, changes were observed in the soil microbial communities associated with specific rotation crops and a reduction in wireworm density was correlatively observed. Thus, our study showed that the root system of buckwheat influences the structure of the microbiome in the rhizosphere as .hypothesized
Aisha Khalifa Dwo Alkhnajari, (09-2019), Canada: Island Scholar,
دراسة مكونات دم إناث الأرانب المغذاة على علف ممزوج بالقرفة
مقال في مجلة علميةاستعمل مسحوق القرفة في هذه الدراسة و بتركيز 20 % مع العلف لمعرفة تأثيراته على مكونات دم إناث الأرانب، إذ أدى تناول نبات القرفة إلى انخفاض معنوي (أ ≤ 0،01) في مستوى كل من اليوريا و الكرياتينين و الكلوسترول و الجليسيريدات الثلاثية و سكر الدم مع ارتفاع معنوي (أ ≤ 0،01) في كلا من أعداد كريات الدم الحمراء و البيضاء مقارنة مع مجموعة السيطرة.
عائشة خليفة ضو الخنجاري، فراس خليل ابراهيم، شهباء خليل ابراهيم، (12-2009)، العراق: جامعة الوصل كلية الطب البيطري، 31