REDGRAM STERILITY MOSAIC VIRUS

PATHOGEN,SYMPTOMS,MANAGEMENT

1. PAT– 302 DISEASES OF FIELD CROPS AND THEIR MANAGEMENT (1+1) ASSIGNMENT TOPIC REDGRAM STERILITY MOSAIC VIRUS SUBMITTED BY, COURSE TEACHER, M.HARISHMADEVI, Dr.PARTHASAARATHY.S , 2015021047. Asst. Prof., (PLANT PATHOLOGY).

2. HISTORY Pigeonpea sterility mosaic virus (PPSMV), a species of the genus Emaravirus , is the causal agent of sterility mosaic disease (SMD) of pigeonpea [ Cajanus cajan ]. This disease, dubbed the 'green plague', as the infected plants remain in the vegetative state without flower production, has been reported from India and a few other South-East Asian countries. SMD is estimated to result in an annual yield loss of over US$300 million in India alone.

3. EMARAVIRUS Emaravirus is a genus of plant viruses. The genus has Five species: European mountain ash ringspot -associated virus (type species), Fig mosaic virus, Pigeonpea sterility mosaic virus , Raspberry leaf blotch virus , and Rose rosette virus .

4. SYMPTOMS The Symptoms are characterized by bushy and pale green appearance of plants. The excessive Vegetative growth , stunting, prominent mosaic on leaves and reduction in leaf size. Complete or partial cessation of flowering leads to sterility .

5. Excessive vegetative growth and fail to produce flowers (sterility). The leaves are small and show a light and dark green mosaic pattern initially appear on young leaves. Only some parts of the plant may show disease symptoms, and other parts remain normal.

6. Depending on genotype three types of Symptoms are recognized. a. Severe mosaic and sterility b. Mild mosaic and partial sterility c. Chlorotic ringspot without any noticeable sterility.

7. STERILITY MOSAIC DISEASE © agritech.tnau.ac.in

8. STERILITY MOSAIC DISEASE © agritech.tnau.ac.in

9. Light and dark green mosaic pattern on leaves © agrimoon.ac.in

10. Sterility mosaic : Tenui like virus © agrimoon.ac.in

11. SYSTEMATIC POSITION Group : Group V ((−) ssRNA ) Order : Bunyavirales Family : Fimoviridae Genus : Emaravirus Species : Redgram sterility mosaic virus

12. MODE OF SPREAD Through vector – Aceria cajani ( eriophyid mite) Aceria cajani in a semi persistant manner, mites retaining the virus 12-13 hours, eggs of mites do not transmit . The self grown redgram plants and perennial species act as source of virus inoculums.

13. PATHOGEN It is caused by Pigeonpea sterility mosaic virus(PPSMV). The virions are slender highly flexuous filamentous virus like particles (VLPS) of 3-10nm diameter , a major virus specific proteins of 32kDa and 5-7major RNA species of 0.8-6.8kb.

14. Eriophyid mite- Aceria cajani © agritech.tnau.ac.in

15. FAVOURABLE CONDITIONS Caused by Pigeonpea sterility mosaic virus (PPSMV) A single Eriophyid mite vector ( Aceria cajani ) is sufficient to transmit the disease. Perennial, ratooned and volunteer pigeonpea provide mite vector and the pathogen.

16. Shade and humidity encourage mite multiplications. Disease incidence is high when Pigeon peas are inter-mixed cropped with sorghum or millets.

17. STERILITY MOSAIC VIRUS OF REDGRAM © agritech.tnau.ac.in

18. INTEGRATED DISEASE MANAGEMENT (IDM) Rogue out infected plants up to 40 days after sowing . Spray Monocrotophos at 500 ml /ha soon after appearance of the disease and if necessary, repeat after 15 days .

19. INTEGRATED DISEASE MANAGEMENT (IDM) G row resistant genotypes/cultivars like ICP 7035, VR3 , Purple 1, DA11, DA32, ICP 6997 , Bahar , BSMR235 , ICP 7198, PR 5149, ICP 8861 and Bhavanisagar 1.

20. REFERENCES http://www.biologydiscussion.com/plants/plant-diseases/sterilitymosaic-disease-of-pigeonpea-plant-diseases/43226 http://agropedia.iitk.ac.in/content/sterility-mosaic-disease-pigeonpea www.agrimoon.com