No abstract

Algeria is a country known for a varietal variety of Citrusfruits, which are susceptible to serious pathologies such as stubborn disease (Spiroplasma citri), causing significant economic losses. The current study was conducted in order to investigate the possible existence of different Spiroplasma citri strains in Algeria. Samples of fresh leaves and orange-tree fruits (Citrus sinensis L.) with stubborn symptoms were detected in Boumerdes and Blida province. Identification of the causative agent (Spiroplasma citri) was ensured by ELISA and PCR techniques. DNA extracted from symptomatic samples were used as a template for amplification of products of 675 bp using primer pairs Spiralin (Sc1 / Sc1-) and (SpiF / SpiR) by PCR. Furthermore, the spiralin gene was cloned and sequenced. About 18,23% of the samples, showing clear-cut stubborn symptoms, were ELISA-positive. Molecular characterization by sequence analysis has identified two Algerian isolates with 99% homology between them. Spiroplasma citri Isolate 12 (OQ078580) and Spiroplasma citri isolate 14 (OQ068387). Phylogenetic tree showed that the Algerian Spiroplasma citriisolates are more closely related to the Egypt, Israel, than those isolated from Iran and Corse.