Identification and genetic diversity in phytoplasmas associated with diseases of cassava and other agronomic relevant crops in south-east Asia and Latin America

Identification and genetic diversity of phytoplasmas infecting tropical plant species, selected among those most agronomically relevant in South-east Asia and Latin America were studied. Correlation between evolutionary divergence of relevant phytoplasma strains and their geographic distribution by comparison on homologous genes of phytoplasma strains detected in the same or related plant species in other geographical areas worldwide was achieved. Molecular diversity was studied on genes coding ribosomal proteins, groEL, tuf and amp besides phytoplasma 16S rRNA. Selected samples infected by phytoplasmas belonging to diverse ribosomal groups were also studied by in silico RFLP followed by phylogenetic analyses. Moreover a partial genome annotation of a ‘Ca. P. brasiliense’ strain was done towards future application for epidemiological studies. Phytoplasma presence in cassava showing frog skin (CFSD) and witches’ broom (CWB) diseases in Costa Rica - Paraguay and in Vietnam – Thailand, respectively, was evaluated. In both cases, the diseases were associated with phytoplasmas related to aster yellows, apple proliferation and “stolbur” groups, while only phytoplasma related to X-disease group in CFSD, and to hibiscus witches’ broom, elm yellows and clover proliferation groups in CWB. Variability was found among strains belonging to the same ribosomal group but having different geographic origin and associated with different disease. Additionally, a dodder transmission assay to elucidate the role of phytoplasmas in CWB disease was carried out, and resulted in typical phytoplasma symptoms in periwinkle plants associated with the presence of aster yellows-related strains. Lethal wilt disease, a severe disease of oil palm in Colombia that is spreading throughout South America was also studied. Phytoplasmas were detected in symptomatic oil palm and identified as ‘Ca. P. asteris’, ribosomal subgroup 16SrI-B, and were distinguished from other aster yellows phytoplasmas used as reference strains; in particular, from an aster yellows strain infecting corn in the same country.

Beyond weaponry and socialist internationalism: Soviet engagement with postcolonial state-building in the Arab Middle East, 1954-1966

This research investigates the Soviet Union’s role in guiding state-building processes of postcolonial Arab countries of the Middle East, leading them to adopt economic and political elements of the socialist-Leninist models of development. The widespread narrative depicts the Soviets as having failed to export communism in those states and, therefore, as having failed to bring them closer to Moscow’s sphere of influence and values. However, various Soviet archives suggest a different reality. As the Cold War burst forth, between the mid-1950s and mid-1960s, contacts between Soviet and Arab officials were not just incredibly frequent but they went to the core of all main issues of socio-economic development of these transforming countries: party politics, institution building, agrarian reforms, industrialisation, security sector reforms, etc. The research focuses on a period that may be labelled as ‘the launching phase’ of the Soviet Middle East policy, which established a long-lasting framework for the Soviet-Arab dialogue. It also places significant attention on the ‘personal dimension’ of such a dialogue, showing how Moscow’s influence went hand in hand with the ability of Soviet leaders and diplomats to establish relations of personal trust with postcolonial Arab élites. A selected number of Arab countries are examined: Egypt, Iraq and Syria. For each of these countries, a limited period of time will be taken into consideration, when Soviet influence reached its peak and state-building policies might have drawn from the Soviet model (for Egypt 1954-1958; for Iraq 1958-1963; for Syria 1961-1966). On the one hand, the analysis of specific case-studies will allow to investigate the relationship between Moscow and each of these new Arab regimes; on the other, such a large geographical scope will permit to grasp the elements and the objectives of the broader Soviet policy towards the Middle East region.