Browsing by Author "Uke, Ayaka"

Now showing 1 - 1 of 1

Characterization of rice yellow mottle virus in north-eastern Tanzania
(The University of Tokyo, 2015) Uke, Ayaka; Tibanyendela, Naswiru; Natsuaki, Keiko T; Sekiya, Nobuhito; Oizumi, Nobuaki
Rice (Oryza sativa L.) is an important cereal-grain in some African countries and known to be attacked by Rice yellow mottle virus (RYMV). Rice plants with virus like symptoms were collected from lower Moshi and other areas in the north-eastern region of Tanzania. RYMV was detected by DAS- ELISA, RT-PCR and/or electron microscopy from almost all collected samples. Some RYMV isolates were sequenced and identified as strain S4. Also, three of them, Tz-12-20, Tz-12-22 and Tz-10-36, were clustered as a new group named S4-mk (Mt. Kilimanjaro). Cluster of S4-mk formed a monophyletic group of isolates in strain S4-lv reported from the Tanzanian side of the Lake Victoria. However, S4-mk and S4-lv lineages are separated from each other and S4-mk has the characteristic three amino acid substitutions. The isolates of S4-mk were also closely related to that of strain S4-mg. Amino acid sequences of the coat protein of the isolates in group S4-mk showed over 96% identity with those in other strain S4 varieties, S4-lv, S4-mg and S4-lm. The phylogenetic tree also indicated the possibility of strain S4-mk to have dispersed from south-western Kenya to north eastern Tanzania. As for the serotyping, followed by Fargette et al. (2002), these three isolates in S4-mk were classified into serotype 4.