Identification and Quantification of Polymyxa graminis f. sp. temperata and P. graminis f. sp. tepida on Barley and Wheat

Abstract

Polymyxa graminis f. sp. temperata and P. graminis f. sp. tepida are distinguished on the basis of their specific ribosomal DNA sequences. In order to evaluate whether or not host specialization is associated with the special form, the occurrence of infection of both forms on barley and wheat was studied. P. graminis inocula were obtained from soils collected in Belgium and France. Their ribotypes were characterized using molecular tools specific to P. graminis f. sp. temperata or P. graminis f. sp. tepida such as restriction fragment length polymorphism (RFLP) analysis of polymerase chain reaction (PCR)-amplified rDNA, nested and multiplex PCR. Both special forms were found in each country and coexisted in some soils. The host specificity of P. graminis special forms for barley and wheat was studied from two soils collected at Gembloux (Belgium) and Chambon-sur-Cisse (France), each infested by bymo- and furoviruses. P. graminis f. sp. temperata is more frequent on barley and P. graminis f. sp. tepida on wheat. Furthermore, the quantification of each form on barley and wheat by two separated real-time quantitative PCR assays confirms the observations on the vector specialization. These results suggest a certain but not exclusive host specificity of P. graminis special forms.

Occurrence ofPolymyxa graminisRibotypes in Germany and Their Association with Different Host Plants and Viruses

“…Both ribotypes I and II were found to be ubiquitous in Germany, and they can occur together at the same location. This was also the situation reported previously by Smith et al (2013); Vaianopoulos et al (2007) and Ward et al (2005) in Europe, and recently for southwest Australia (Cox et al 2014). Figure 2.…”

“…temperata was found to be more frequent on barley, and f. sp. tepida -on wheat and other cereals (Ward et al 2005;Vaianopoulos et al 2007). Dieryck et al (2011) have shown that the PCV transmission efficiency depends on the P. graminis special forms.…”

Detection of Polymyxa graminis in a barley crop in Australia

“…Both types occurred together in some soils and plants. Vaïanopoulos et al (2007) confirmed these preferential associations and showed by real-time PCR that infection with P. graminis f. sp. temperata was greater on barley than on wheat, whereas infection with P. graminis f. sp.…”

“…Previously P. graminis f. sp. tepida has been recorded in barley, wheat, oats and rye from Canada, UK, France, Belgium and Germany (Ward and Adams 1998;Kanyuka et al 2003;Vaïanopoulos et al 2007). Legrève et al (2002) have recognised five subgroups of P. graminis based on sequence type of nuclear ribosomal DNA containing ITS1, the 5.8S rDNA and ITS2.…”

Epidemiología, caracterización molecular y desarrollo de métodos de diagnóstico del virus de las manchas necróticas del melón (MNSV) y de su hongo vector Olpidium Bornovanus.

“…temperata and P. graminis f. sp. tepida in barley and wheat (Vaïanopoulos et al, 2007). Our laboratory has developed a novel multiplex PCR assay for the rapid and simultaneous detection and differentiation of three Olpidium spp.…”