Panicle bacterial blight caused by Burkholderia glumae is a widespread and economically important disease of rice in Colombia. Studies have found that B. glumae and the less aggressive B. gladioli cause the disease. B. glumae populations in Colombia are highly diverse and cluster into five main genetic groups correlated with geographical location. Evaluation of pathogen strains on the susceptible rice variety Colombia XXI found pathogenicity is variable, with some strains causing over 50% damage while others less than 20%. This information is being used to screen germplasm for disease tolerance.

1. Panicle bacterial blight in Colombia:
g
knowing the enemy as a first step in finding
control alternatives
Gloria Mosquera, Plant Pathologist
Rice Plant Pathology Program
gy g
International Center for Tropical Agriculture, CIAT
Cali, Colombia

2. Presentation Outline
•General Background
• St di on di
Studies disease cycle i greenhouse
l in h
•Identification of causal agent on field samples
•Disease distribution and variability
•Current activities and future work
Current

3. General Background
Causal Agent
Burkholderia glumae
g A
Symptoms:
Grain discoloration, infertility
Straight panicle
Straight panicle
Sheath rot in seedlings (Mainly in nurseries, not frequent in
field)
Reported in Colombia in 1987 (Zaigler and Alvarez)

4. Seed‐Born disease but…
Not only infected seeds seem to be required for disease development
N l i f d d b i d f di d l
Greenhouse observations
Greenhouse observations
Field conditions
3. Symptoms on flowers
3 S fl Plants without
(bacteria concentration symptoms not
increased) even in flowers
2. Epiphytic phase
(low bacteria concentration)
Infected
seeds
1. Bacteria seed‐transmitted

5. 1
Identificación por PCR
Disease widely Depto. Localidad B.
2 (%) 3 B. gladioli
2
(%) 3
glumae
distributed in Colombia
distributed in Colombia
Antioquia 1 2(1) 50 2(0) 0
Atlántico 1 1(0) 0 1(0) 0
B. gladioli has been also
B gladioli has been also Bolívar 2 4(3) 75 4(0) 0
detected. First report in
Casanare 1 1(0) 0 1(0) 0
Colombia.
(
(Poster by P. Fory)
y y) Cesar 3 17(12) 71 11(6) 55
CIAT 1 157(59) 38 68(10) 15
Córdoba 4 11(8) 73 11(0) 0
Huila 3 7(2) 29 6(1) 17
Meta 6 40(19) 48 26(3) 12
Santander 1 2(2) 100 1(0) 0
Sucre 1 5(2) 40 5(0) 0
Tolima 13 94(58) 62 50(8) 16
V. del
2 3(1) 33 3(1) 33
Cauca
Total 39 344(167) 49 189(29) 15

6. B. glumae vs B gladioli
B.glumae more aggressive
B. gladioli less aggressive
B. gladioli less aggressive
but similar symptoms

7. B. glumae is widely
distributed in Colombia Cepa Registro Departame
nto
Municipio Variedad Pigmentación
but how diverse is the 1
2
3161‐2
3193‐No 4
Sucre
Córdoba
San Marcos
La victoria
Fedearroz 2000
Fedearroz 2000
Pigmentada
Pigmentada
3 3193‐No 5 Córdoba La victoria Fedearroz 2000 No Pigmentada
population? 4
5
3196‐10
3200‐12
Meta
Córdoba
Santa Rosa
La victoria
Oryzica Llanos 5
Fedearroz 2000
No Pigmentada
Pigmentada
(Poster by D. Bravo) 6 3252‐ 8 Antioquia Nechi Desconocida Pigmentada
7 3455‐1
3455 1 Bolívar San Jacinto
San Jacinto Fedearroz 733
Fedearroz 733 Pigmentada
8 3459‐4 Bolívar María la baja Fedearro473 Pigmentada
Location where disease has an effect on yield 9 3643‐2 Córdoba Lorica Arroz rojo Pigmentada
10 3646‐1 Córdoba Lorica Fedearroz 2000 Pigmentada
11 3650‐3 Córdoba Lorica Fedearroz 733 Pigmentada
12 3651‐1 Córdoba Montería 71 Pigmentada
13 3651‐4 Córdoba Montería Fedearroz 733 No Pigmentada
14 3656‐1 Córdoba Montería Mezc. Fedearroz Pigmentada
15 3659‐1 Córdoba Montería Fedearroz mejor. Pigmentada
16 3718‐2 Tolima Ambalema Or‐370 Pigmentada
17 3722‐1 Tolima Guamo CimarronBarinas Pigmentada
18 3807‐9 Tolima Espinal Orizya 1 Pigmentada
19 3809‐2 Tolima Guamo Fedearroz 60 Pigmentada
20 3818 8
3818‐8 Tolima Venadillo Clearfield 370
Clearfield‐370 Pigmentada
21 3825‐14 Tolima Venadillo Fedearroz 60 Pigmentada
22 3847B‐10(S) Meta Santa Rosa Fedearroz 174 Pigmentada
23 3848‐5(S) Meta Santa Rosa Fedearroz 134 Pigmentada
24 3851‐4 Meta Santa Rosa 71 Pigmentada
25 3853‐4 Tolima Progreso CimarronBarinas Pigmentada
26 3854‐2 Tolima Prado CimarronBarinas Pigmentada
27 3855‐4 Tolima Progreso
Progreso Coprosem 304
Coprosem 304 Pigmentada
28 3856‐5 Tolima Parificación CimarronBarinas Pigmentada
29 3858‐2 Tolima Parificación Coprosem 304 Pigmentada
30 3859‐5 Tolima Santa Inés CimarronBarinas No Pigmentada
31 3861‐2 Meta Santa Rosa RD‐FLAR 18 Pigmentada
32 3862‐3 Meta Santa Rosa RD‐FLAR 28 Pigmentada
33 3864‐4 Meta Santa Rosa RD‐FLAR 68 Pigmentada
34 3866B 10
3866B‐10 Santander Cúcuta Fedearroz 733
Fedearroz 733 Pigmentada
35 3880‐7 Cesar Tamalameque Fedearroz 2000 Pigmentada
36 3883‐8 Meta Villavicencio Improarroz 1550 Pigmentada
37 3889A‐2 Tolima Armero Panorama 20‐08 Pigmentada
38 3890‐4 Tolima Saldaña Coprosem 1 Pigmentada
39 3891A‐1 Tolima Ibagué Aceituno Pigmentada

8. B. glumae population is highly diverse
5 main genetic clusters correlated with geographical
BOX-PCR profiles location
Eastern plains
North
N th
Center
Meta
Mixed

9. Adjusting a system for strain
aggressiveness/host response evaluation
B.
B glumae Water
Panicle inoculation
Colombia XXI highly susceptible
Non pigmented strains as reference
Evaluation after 14 days of inoculation

10. Establishment of evaluation system
•Colombia XXI was susceptible
to most of the strains
•Pathogenic strains> 50%
damage
•Low pathogenic <20%
damage
The same system is being used to screen germplasm looking for tolerance
sources
Strains representing all genetic clusters are being included in this evaluation
Tolerant materials (hot spot) will be challenged with multiple location strains.

11. OUR TEAM
Gustavo Prado
Paola Fory
Girlena Aricapa
Liliana Bolaños
Carlos Prado
Luis Rosero
Fomer members
Daniela Bravo
OUR COLLABORATORS
FEDEARROZ
FLAR
MADR