@article{fdi:010096812,
  title = {{F}irst report of {X}anthomonas oryzae pv. oryzicola causing bacterial leaf streak of rice in {U}ganda [r{\'e}sum{\'e}]},
  author = {{A}folabi, {O}. and {M}ilan, {B}. and {P}oulin, {L}. and {O}ngom, {J}. and {S}zurek, {B}oris and {K}oebnik, {R}alf and {S}ilue, {D}.},
  editor = {},
  language = {{ENG}},
  abstract = {{I}n {J}une 2013, symptoms reminiscent of bacterial leaf streak ({BLS}) caused by {X}anthomonas oryzae pv. oryzicola were observed on rice plants at the booting stage in the {D}oho rice irrigation scheme, {B}utaleja district, and at the tillering stage in {N}ambale, {I}ganga district and {M}agada, {N}amutumba district of {U}ganda. {I}n areas surveyed, disease incidence was about 80, 40, and 30% in {D}oho, {N}ambale, and {M}agada, respectively. {O}utside the irrigation schemes, it was lower but widespread. {A}ffected leaves showed typical {BLS} symptoms, such as water-soaked lesions, translucent stripes, and yellow-brown to black streaks, sometimes with visible exudates at the leaf surfaces. {T}o check for the presence of the bacteria, symptomatic leaves were ground in sterile water and the suspension obtained was subjected to a multiplex {PCR} assay for {X}. oryzae pathovars, leading to the three diagnostic {DNA} fragments for {X}. oryzae pv. oryzicola (3). {I}n parallel, bacterial strains were isolated from surface-sterilized symptomatic leaves. {T}o this end, rice leaves were ground in sterile distilled water and serial dilutions of the cell suspensions were plated on semi-selective {PSA} medium (4). {E}ach of the three samples yielded yellow, mucoid {X}anthomonas-like colonies that resembled the positive control strain {MAI}10 (1). {T}hese isolates were named {U}g_1, {U}g_10, and {U}g_14, which originated from {D}oho, {M}agada, and {N}ambale, respectively. {M}ultiplex {PCR} on the pure cultures strongly supported that these isolates corresponded to {X}. oryzae pv. oryzicola. {T}wo isolates, {U}g_1 and {U}g_14, were further subjected to partial {DNA} sequence analysis of the gyr{B} gene upon {PCR} amplification using the primers {X}gyr{B}1{F} and {X}gyr{B}1{R} (5). {T}he 467-bp {DNA} sequence was identical to the gyr{B} sequences from the {X}. oryzae pv. oryzicola strains {BLS}256 ({P}hilippines), {ICMP} 12013 ({C}hina), and {MAI}3 ({M}ali) (2). {T}he partial nucleotide sequence of the gyr{B} gene of strain {U}g_1 was submitted to {G}en{B}ank ({KJ}921786). {P}athogenicity tests were performed on greenhouse-grown 4-week-old rice plants of the cultivars {N}ipponbare, {A}zucena, {IRBB} 1, {IRBB} 2, {IRBB} 3, {FKR} 14, {PNA}64{F}4-56, {TCS} 10, {G}igante, and {A}dny 11. {F}or this purpose, bacterial cultures were grown overnight in {PSA} medium and re-suspended in sterile water at a concentration of 1 × 108 {CFU}/ml. {B}acterial suspensions were sprayed on leaves of rice seedlings. {F}our seedlings per accession and isolate were inoculated. {F}ifteen days after incubation in a {BSL}-3 containment facility (27 ± 1°{C} with a 12-h photoperiod), inoculated leaves exhibited typical water-soaked lesions with yellow exudates that were similar to the symptoms seen in the fields. {R}e-isolation of the bacteria from the diseased leaves yielded colonies with the typical morphology of {X}anthomonas. {M}ultiplex {PCR} and sequence analysis of portions of the gyr{B} gene confirmed that these isolates are {X}. oryzae pv. oryzicola, thus fulfilling {K}och's postulates. {O}ne of the three isolates, {U}g_1, has been deposited in the {C}ollection {F}ran{\c{c}}aise de {B}act{\'e}ries {P}hytopathog{\`e}nes ({CFBP}) as strain {CFBP} 8171 ( http://www.angers-nantes.inra.fr/cfbp/). {F}urther surveys and strain collections in {E}ast and {C}entral {A}frica will help assess the geographic distribution and importance of {BLS}.},
  keywords = {{OUGANDA}},
  booktitle = {},
  journal = {{P}lant {D}isease},
  volume = {98},
  numero = {11},
  pages = {1579},
  ISSN = {0191-2917},
  year = {2014},
  DOI = {10.1094/pdis-07-14-0745-pdn},
  URL = {https://www.documentation.ird.fr/hor/fdi:010096812},
}