Diverse phytoplasmas associated with leguminus crops in Russia

Authors: GIRSOVA, NATALIA - Russian Institute Of Phytopathology; Bottner, Kristi; BOGOUTDINOR, DAMIR - Russian Institute Of Phytopathology; KASTALYEVA, TATYANA - Russian Institute Of Phytopathology; MESHKOV, YURI - Russian Institute Of Phytopathology; MOZHAEVA, KARINA - Russian Institute Of Phytopathology; Lee, Ing Ming

Submitted to: European Journal of Plant Pathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 3/2/2017
Publication Date: 3/17/2017
Citation: Girsova, N.V., Bottner-Parker, K.D., Bogoutdinor, D.Z., Kastalyeva, T.B., Meshkov, Y.I., Mozhaeva, K.A., Lee, I. 2017. Diverse phytoplasmas associated with leguminus crops in Russia. European Journal of Plant Pathology. 149:599.

Interpretive Summary: Legume crops, notably, clover and alfalfa are economically important food crops grown in Russia. They are good sources of protein for domestic animals. They can also be used as green manure or fertilizer to conserve land fertility. In Russia, alfalfa and clover are widely grown in the Central Economic and Volga Regions. One of the growth-limiting factors that significantly reduce the production of legume crops is phytoplasmal infection. Based on symptoms characteristic of phytoplasma infection, several different diseases have been reported for decades to be widespread in four Economic Regions of Russia, Northern (Arkhangelsk and Vologda oblast), Central (Moscow oblast), Volga (Samara oblast) and West Siberian (Novosibirsk oblast). Phytoplasmas are small cell wall-less plant pathogenic bacteria, infecting more than 1000 plant species and causing numerous economically important diseases. Because they cannot be cultured readily in cell-free media, their identities could not be determined until molecular tools were developed by our laboratory. In the present study we, using molecular tools, conduct the first large scale survey in the four Economic Regions for legume phytoplasmal diseases. We concluded that phytoplasma diseases have substantial economic impacts on legume crop production and that phytoplasmas belonging to four groups and subgroups were responsible for phytoplasmal diseases in legume crops in Russia. This information will aid extension workers in Russia for disease control and diagnosticians and will aid implementation of quarantine regulation in the US.

Technical Abstract: A large scale survey of diseased legume plants (mainly clover and alfalfa in the Fabaceae family) was conducted from 2009-2013 in four Economic Regions of Russia - Northern (Arkhangelsk and Vologda oblast), Central (Moscow oblast), Volga (Samara oblast) and West Siberian (Novosibirsk oblast). The majority of infected clover plants exhibited symptoms typical of clover phyllody (CPh), clover yellow edge (CYE), or clover proliferation (CP), and infected alfalfa plants exhibited symptoms typical of alfalfa witches’-broom (AWB). Of 161 samples collected from 22 different legume species, 115 tested positive for phytoplasma infection. Phytoplasmas belonging to four groups and four subgroups were detected, of which 25.2 % were subgroup 16SrI- C (causal agent of CPh disease), 38.3% were subgroup 16SrIII-B (causal agent of CYE disease), 7.8 % were subgroup 16SrVI-A (causal agent of CP and AWB diseases) and 8.7 % were subgroup 16SrXII-A (causal agent of AWB disease). The predominant phytoplasma species detected varied by region. In the Northern and Central Regions, the majority of the phytoplasmas detected belonged to subgroups 16SrI-C and 16SrIII-B. In the West Siberian and the Volga Regions, the phytoplasmas predominately detected belonged to subgroups 16SrVI-A and 16SrXII-A, respectively. Eleven species of insects of the order Hemiptera, suborder Auchenorrhyncha, were collected from leguminous plants in the Moscow oblast of the Central Region. Euscelis incisus and Aphrodes bicinctus were the most prevalent species and may be potential phytoplasma vectors in the Central Region.