TITLE:
Imperata yellow mottle virus: An Emerging Threat to Maize, Sorghum and Pearl Millet in Burkina Faso
AUTHORS:
Moustapha Koala, Valentin Stanislas Edgar Traoré, Drissa Sérémé, Bouma James Neya, Christophe Brugidou, Nicolas Barro, Oumar Traoré
KEYWORDS:
IYMV, Sobemovirus, Host Range, Virus-Host Interactions
JOURNAL NAME:
Agricultural Sciences,
Vol.8 No.5,
May
27,
2017
ABSTRACT: Imperata
yellow mottle caused by Imperata yellow mottle virus (IYMV) of the genus Sobemovirus was
first characterized on Imperata cylindrical and Zea mays in Burkina Faso. The
disease has been reported in several localities of the country but its ecology
and epidemiology are poorly known. In particular, only I. cylindrical and
maize have been reported within IYMV host range. The aim of this study was to
investigate the experimental host range of the virus. Mechanical inoculation of
a mixture of four IYMV isolates to 18 plant species, including four
crops (maize, rice, sorghum and pearl millet) and 14 wild grasses showed clear
mottle symptoms in maize, sorghum and pearl millet and two wild grass species (Setaria
verticillata and Rottboellia exaltata). Symptom development was
confirmed by Enzyme-linked immunosorbent assay and reverse transcription–polymerase
chain reaction (RT-PCR). Infection of crop species by IYMV depended on
cultivars tested. Therefore, proportions of positive cultivars were 16/36 in
maize, 4/10 in sorghum and 4/9 in pearl millet, respectively. Studies on
virus-host interactions using individual virus isolates showed two pathogenic
patterns. Three out of the four isolates tested infected all plant species and
cultivars. In contrast, the fourth IYMV isolate could infect only one maize
cultivar. These results expand the previously known host range of IYMV from two
to five species, indicating a narrow host range. Among the new characterized
host species, sorghum and pearl millet are important cereal crops. Therefore, Imperata
yellow motte disease is a potential threat for the cereal crop production and
its ecology and epidemiology should be thoroughly investigated.