Chemical Control of Bacterial Leaf Blight of Rice

caused by Xanthomonas oryzae.pv oryzae

INTRODUCTION• Rice is the second largest produced cereal in the world.

• Rice belongs to the Genus Oryza L (meaning oriental).

• The genus Oryza is comprised of twenty-five species distributed throughout the tropical and subtropical regions of Asia, Africa, Central and South America and Australia.

• Out of these 25 species, only two are cultivated, Oryza sativa L. and Oryza glaberrima Steud.

• World production of rice has risen steadily from about 200 million tons of paddy rice in 1960 to 600 million tons in 2004 and 700 million tons in 2005 should be 2010.

• Rice is cultivated all over Pakistan under diverse climatic and soil conditions.

• At present, Rice is cultivated in 2.62 million hectares area in Pakistan with a production of 5-6 million tons.

• Punjab is the leading contributor or producer in Pakistan's total output of rice production (3.17 million tons).

• Among Basmati varieties, Super Basmati and Basmati 385 cover about 90 percent of the total rice area in Punjab, and are very popular among the rice growers, millers, exporters and consumers for good aroma high yield and excellent cooking qualities.

PAKISTAN

Constrains to rice production

A biotic stresses:• Temperature.• Salinity.• Drought. • Acidity.• Iron toxicity and submergence under water.Biotic stresses:• Insect pests• Diseases

• The disease was first noticed by the farmers in Fukuoka prefecture Kyushu Island, Japan, as early as in 1884-85 .

• The study of bacterial blight started in Japan in 1901 (Tagami and Mizukami., 1962).

• BLB is the most serious disease in South Asia particularly in Japan, Philippine, Indonesia and India. Yield losses in Japan normally ranged from 20 to 23 % occasionally increasing (Ou, 1985).

• This disease is also serious problem of rice in other parts of Asia (Alim, 1967; Ou, 1985).

• In Pakistan the disease was recorded for the first time by Mew and Majid (1977), later on Ahmad and Majid (1980) reported it on rice varieties IR 6, Palman, Basmati-198 at Rice Research Institute, Kala Shah Kaku and farmer's field.

BACTERIAL LEAF BLIGHT(BLB)

BLB disease symptoms

Shape of pathogen• The causal bacterium Xanthomonas oryzae pv. oryzae is a

yellow, slime producing motile Gram-negative rod with a polar flagellum.

• Cells occur singly, in pairs, or sometimes in chains. Filaments may also occur.

• A viscous capsule like material composed of hetro-polysaccharide covers surface of the bacterial cells.

Disease Development• Bacterial Leaf Blight is a vascular disease. The infection

is, therefore, systemic.

• The pathogen normally enters the host through wounds or natural openings such as the water pores on hydathodes and multiplies in the tissues of the epithelium, in to which xylem vessels open.

• After the bacterial multiplication occurs in epithelium, some of the bacterial cells reach the xylem vessels of the vascular system.

• When a bacterial colony is established in the xylem vessels, the bacterial cells grow vigorously and translocate through the network of the vascular system.

Objectives

• The present studies were aimed at to find out the best chemical control of Bacterial Leaf Blight disease of rice.

• Six antibiotics viz Benzyl Penicillin, Amplicillin, Kanamycin, Streptomycine, Chloramphenicol and SinoBionic were selected to conduct this study.

• Four concentrations of each antibiotic were used in the experiment designed in CRD with three replications in controlling the growth of Xoo isolates in vitro and zones of inhibitions were recorded as control measure.

Isolation and purification of Xanthomonas oryzae pv. oryzae:

• Diseased plant material:• Media Preparation and Sterilization:• Isolation of pathogen from diseased material:

Plating of disease samples and Isolation of pathogen from diseased material

Media Preparation and Sterilization

• Morphological Characterization of Xanthomonas oryzae pv. oryzae :

• Microscopic Characterization of Xoo: • Identification of Bacterial Cultures by Gram’s Staining

Method: • Preservation of Pure Bacterial Cultures:

Purified Xoo cultures on NA slants

Xanthomonas oryzae pv oryzaeunder microscope

Purified Xoo, streaked on NA plate andstudy the Morphological Characterization of Xoo

Chemical Control of Xoo (In vitro) by Using Different Antibiotics Material:

• Benzyle Penicillin Sodium• Ampicillin Sodium• Kanamycin Sulphate• Streptomycin Sulphate• Chloramphenicol Sodium• Sino Bionic

Four Concentrations:31.25ug/ml, 62.5ug/ml, 125ug/ml and 500ug/ml

Final Concentrations of antibiotic solutions

Stock 2 antibiotic solutions

Filling wells with antibiotics

Stock 1 antibiotic solutions.

Clear Zones Measured

Effect of Benzyl Penicillin Sodium on different isolates.

0

5

10

15

20

25

30

35

40

45

31.25 62.5 125 500 31.25 62.5 125 500 31.25 62.5 125 500 31.25 62.5 125 500 31.25 62.5 125 500

Benzylpinicillin Benzylpinicillin Benzylpinicillin Benzylpinicillin Benzylpinicillin

16.5 21.3 2.6 17.1 77.2

concentartin in( ug/ml) and Isolate numbers.

Inhi

bitio

n Zo

nes(

mm

)

Effect of Ampicillin Sodium different isolates.

0

5

10

15

20

25

30

31.25 62.5 125 500 31.25 62.5 125 500 31.25 62.5 125 500 31.25 62.5 125 500 31.25 62.5 125 500

Ampicilline Ampicilline Ampicilline Ampicilline Ampicilline

16.5 21.3 2.6 17.1 77.2

Concentartion(ug/ml) and Isolate numbers.

Inhi

bitio

n Zo

nes(

mm

)

Effect of Kanamycin Sulphate on different isolates

0

5

10

15

20

25

30

35

31.25 62.5 125 500 31.25 62.5 125 500 31.25 62.5 125 500 31.25 62.5 125 500 31.25 62.5 125 500

Kanamycin Kanamycin Kanamycin Kanamycin Kanamycin

16.5 21.3 2.6 17.1 77.2

Concentartion (ug/ml) and Isolate numbers.

Inhi

bitio

n Zo

nes

(mm

)

Effect of Streptomycin Sulphate different isolates.

0

5

10

15

20

25

30

31.25 62.5 125 500 31.25 62.5 125 500 31.25 62.5 125 500 31.25 62.5 125 500 31.25 62.5 125 500

streptomycine streptomycine streptomycine streptomycine streptomycine

16.5 21.3 2.6 17.1 77.2

Concentration (ug/ml) and Isolate numbers.

Inhi

bitio

n Zo

nes

(mm

)

Effect of Chloramphenicol Sodium on different isolates.

0

5

10

15

20

25

31.25 62.5 125 500 31.25 62.5 125 500 31.25 62.5 125 500 31.25 62.5 125 500 31.25 62.5 125 500

chloramphenicole chloramphenicole chloramphenicole chloramphenicole chloramphenicole

16.5 21.3 2.6 17.1 77.2

concentrations (ug/ml) and isolate numbers.

Inhi

bitio

n Zo

nes

(mm

)

Effect of Sinobionic on different Isolates.

Conclusion

• Sinobionic was found the best in controlling growth of the Xoo isolates in vitro at all concentrations (31.25µg/ml.62.50µg/ml.125µg/ml,500µg/ml).

• Kanamycine was at second number to control the growth

• chloramphenicole was found the least effective in controlling the growth of Xoo.