The document discusses several plant pathogens that were introduced to India from other countries, including late blight of potato from England in 1883, rice blast from China/Japan, and coffee leaf rust from Sri Lanka in 1870, which caused significant crop losses upon introduction. It also outlines quarantine procedures used by the National Bureau of Plant Genetic Resources in India to screen transgenic seed introductions from other countries between 2006-2013, which resulted in the detection and treatment of eight pathogenic fungi on various crops.

1. WELCOME
1

2. 2

3. IntroductionInsects, mites, nematodes, fungi, bacteria, viruses, MLOs and other organisms are known to attack various
crops of economic importancewhen introduced knowingly orunknowingly from exotic country.
These pests and pathogensnot only reduce the quantity but alsospoil the quality ofthe produce to a
considerable extent.
About crop losses due to the pests and diseases, legendarywheat pathologist, E.C. Stakman (1969) said,
'Weeds, insect-pests and plant diseasesreduce the potential agriculturalproduction in the by 23 percent.
The loss of potential food that has been aborted, spoiledor damagedwould be enough to feed at least 75
million human beings in the country.
Hence, Quarantine is the important approach to prevent these exotic alienspecies.

4. Introduced plant pathogens to India

5. Late blight of potato (Phytopthera infestance )
Intro. From England to india in 1883.
Butler and Lal reported earlier incidance of lateblight of potato in india.
First noticed in Nilgiri hills between 1870-1880 and then darjaling district in 1883.
70% of loss-susceptible varieties in epidemic years.
Appears on foliage and tubers , early infection 100% yield loss.
High epiphytotics in punjab 1997-98 due to continuous and long spells of intermittent
rains and froggy weather conditions.
First noticed in certain districts of Hoshiapur in Nov. 1997. In severe cases 100% yield
loss noticed in districts of Hoshiapur, Jalandhar, Amrithsar, Kapurthala, Fategarh sahib
and Fatiala.

6. Symptoms of late blight on potato. Early symptoms on young leaves (A) and stems (B). Appearance of white sporangia on
the underside of infected leaf and on stem (C). Blight and death of infected tissues (D). Browning and rotting of tubers (E
& F)

7. Cont,,,
Loss in tuber yield varied 15-100% depending upon variety and stage of crop
attacked.
Loss in crop yield noticed 40-45% in Hariyana, 15-50% in UP, 5-10% in
Bihar and WB.
According to CPRI:
1-30% Freshly harvested tubers are infected and 0.2-0.3% carry infection to
cold storage.
Today disease occurs regularly moderate to severe form in Himalayan hills,
Indo-gangetic plains and Nilgiri hills of TN.

8. Helminthosporium oryzae (Brown leaf spot of rice)
Disease prevail in all rice growing areas of the world.
In India, disease occurs especially in the heavy monsoon areas of WB,
eastern parts of Assam, UP, TN and parts of Kerala.
The disease is known to cause enormous loss in the leaf spotting stage,
when it assumes epiphytotic stage.
First report Madras, 1919.
Most recent out-brake in Bengal, 1943, loss is 90%.
Bendi and Gill-Loss in grain yield 4.6-29%.
Kawada – annual loss 22000-28000 tonnes.

9. Rice blast (Pyricularia oryzae)
Occurrence of disease suspected as long as rice is cultivated.
Disease is known by different names in various countries.
Early records China, Japan and Italy.
Globally no. 1 disease bcz. of destructiveness, can cause huge
loss of yield.
In India first report-1913.
Became devastated in1919 –Thanjavur delta of TN.

10. Cont,,,,
Occurrence- costal areas and hilly tracs of the sub Himalayan range,
Kashmir and to the northern states of India.
Max. damage in upland rice in1960- semi-dwarf varieties and high
yielding varieties.
The incidence become insignificant especially in plains of northern India
during kharif season.

11. Coffee leaf rust( Hemiliea vastatrix)
Most common and destructive.
First report- Ceylon, Srilanka in 1868.
India-1870.
First report- Karnataka.
Thereafter rust occurred in every year , threatening the coffee
industry.
Occurrence-KA, Kerala and MP where coffee is extensively
grown.
Within a decade of its appearance in ceylon, the rust paralyzed
the coffee cultivation to such an extent that many plantations
were abandoned.

12. Cont,,,
A similar situation occurred in some parts of southern India, but the
disease spread was less devastating there, and coffee, perticularly of
the rust tolerant cultivar C. robusta continues to be grown in the
area.

13. Sunflower downy mildew(Plasmopara halstidii)
In India, the important constraints in sunflower cultivation, particularly in the
Marathwada region of Maharashtra state, is the downy mildew disease caused by
plasmopara.
The disease has been introduced to most of the sunflower growing countries of the
world , including India mainly through the seed trade.
The disease was first noticed in 1984 on cv. modern in the Manjra command area
Lathur and Maharashtra.
Since the disease is seed, soil and air borne, it is difficult to eradicate from the area
of its establishment.

14. Scleropthera rayssiae var. zeae (Downy mildew of maize)
Payak and renfro first reported th disease from Pantnagar, Uttar
Pradesh, in 1967.
There are nine different fungus species that are reported to cause
downy mildew of corn. Five of these, Sclerospora phillipinensis,
S. sacchari, S.maydis, S. sorghi and sclerophthora var. zeae
caused economic losses of corn in Southeast Asia .
The discovery of Sleropthora restricted to India and severe
outbreaks have been reported from several states.
Several other fungal plant pathogens introduced in India from time
are causing significant loss and are considered to be of economic
importance.

15. Phytopthera parasitica var. nicotianae (Blank shank of tobacco)
This disease has been known in the Dutch East Indies for 60 years.
This was introduced in India in 1983 and today occurs sporadically in every
type of tobacco grown under high rainfall or irrigated conditions in the light
soils of Karnataka, Andra Pradesh and Gujrat.

16. Cont,,,,
Nursery growers have sustained severe losses due to blight disease of
tobacco in seedlings.
During the rainy season the disease appears first on lower leaves then,
following a rain shower, the spread of disease is fast, and eventually wet
rot results.
In 1953, during the week preceding the outbreak of epiphytotic, the
humidity was greater than 90 % on all days and the temperature varied
from 74 f to 89f.

17. Bacterial leaf blight of paddy ( Xanthomonas oryzae pv. oryzae)
Bacterial blight was reported from the Philippines almost 60 years ago, and it remained a
minor disease until1950, when it attracted attention in japan.
In India , bacterial was first reported in 1951 in Khopoli area near Bombay, but at that time
the pathogen responsible had not yet been identified.
srinivasan et al. reported that bacterial blight is caused by a strain Xanthosmonas oryzae. The
blight has is most common on foliage. a detailed survey showed that the disease was in most
of the rice growing states of India.

18. Cont,,,
The disease broke out in epidemic form in the Shahabad district of Bihar in 1963.with introduction
of variety Taichungntive 1, the disease appeared In a severe form in 1966 throught out india . the
disease is of common occurrence throughout th Punjab , with severe losses being sustained in certain
districts.
There was a maximum of 47.2% incidence with 54% disease severity in Amritsar during 1994.
Similarly, during 1996 crop season maximum of 76.4% incidence and 41%disease severity were
recorded in Kaputhala districts.
Bacterial blight is currently major hurdle in stepping up rice cultivation. Losses due to bacterial
blight can reach 50%.

19. National Bureau of Plant Genetic Resources (NBPGR) New Delhi is the nodal
agency for introduction of exotic germplasm including transgenics for research
purpose in India.
A range of transgenic crops have been developed across the world which are either
herbicide-tolerant or insect resistant, or tolerant to drought/ stress or offering
nutritional benefits, etc.
India is also undertaking research in developing transgenics in different crops.
During 2006-2013, a total of 4557 transgenic seed samples of various crops were
introduced from different countries.

20. Meterials and methods:
All the seed samples were first examined visually and then under stereo-binocular microscope for the presence of
fungal mycelium/ fructifications such as ergot/ sclerotia, rust pustules, smut and bunt balls and symptoms such as
discolouration, deformation, malformation and for fungal spores adhered on the seed surface of various crops.
The unhealthy-looking seeds of all the crops and leaf/ seed powder were subjected to blotter test. Due to less
quantity, three to five seeds of each sample were placed on 3 layers of moist blotters in plastic petri plates and
incubated for 7 days at 22±10C under alternating cycles of 12 hr light and darkness.
Observations for the associated pathogenic fungi and bacteria were recorded on the 8th day under stereo-binocular
microscope. Slides were prepared and observed under compound microscope for identification of fungi.
All the samples of Oryza sativa were subjected to mandatory prophylactic hot water treatment at 520C for 30
minutes against bacteria and nematodes while infected samples of other crops were salvaged by seed treatment
with a mixture of fungicides- Bavistin (0.5%) + Dithane M-45 (1.25%).

21. Results:
Seed health testing of these samples for quarantine clearance resulted in the
detection of eight pathogenic fungi viz., Alternaria padwickii in Oryza sativa;
Bipolaris maydis in Zea mays; B. oryzae and B. sorokiniana in O. sativa;
Fusarium verticillioides in Arabidopsis thaliana, Brassica spp., Gossypium
hirsutum, Solanum esculentum, O. sativa and Z. mays; F. oxysporum f. sp.
vasinfectum in G. hirsutum; Phoma sorghina in O. sativa and Arabidopsis
thaliana; Rhizoctonia solani in O. sativa and Zea mays.
All the 740 samples found infected were salvaged before their release to the
indentors.

22. 22
LIST OF PLANT DISEASES OF QUARANTINE SIGNIFICANCE IN INDIA.
•Moko wilt of banana
•Bacterial wilt and ring rot of potato
•Black pod of cocoa
•Powdery rust of coffee
•Sudden death of oak
•South american leaf blight of rubber
•Blue mold of tobacco
•Tropical rust of maize
•Barley stripe mosaic virus
•Coconut cadang cadang viroid
•Palm lethal yellowing
•Pine wood nematode
•Red ring nematode of coconut
•Vascular wilt of oil palm
Soybean downey mildew

23. 23