Last Updated: 09 February 2017
A. Fruit crops:
Papaya ringspot virus (PRSV):
PRSV symptoms on leaf (A & B), on petiole (C) and electron micrograph of PRSV particles (D).
Development of tolerant lines
- Pune Selection-3 and Pune Selection-1 were identified as PRSV tolerant lines.
PRSV tolerant papaya line Pune Selection-1 and 3 (PS-1 and PS-3) against susceptible check Red Lady.
- Pune Selection-1 (yellow pulp) and Pune Selection-3 (pink pulp) dioecious papaya lineswith field tolerance for PRSV-P have been registered with National Germplasm Registration Committee, ICAR, New Delhi.
- Gynodioecious character is being introduced both in PS-1 and PS-3 and new gynodioecious lines, PS-1-1 and PS-3-1, are being developed. They are under field testing stage.
Field demonstration of the technology developed by ICAR-IARI, RS, Pune:
Integrated management of PRSV in papaya
- Integrated management:
- Use of tolerant lines,
- Planting of 3-5 border rows of banana/ maize around papaya,
- Planting of papaya when the aphid population is low i.e. February in Pune,
- Fortnightly foliar application of insecticides like dimethoate (0.05%) and Neem oil (0.1%) alternately.
Standardization of nursery practices
- Nursery practices of raising virus-free papaya seedlings were developed.
- A new phytoplasma disease of papaya was reported for the first time from India.
|Symptoms of phytoplasma infection on papaya (A) and its detection by PCR (B).
- Combined infection of phytoplasma and PRSV was reported for the first time in papaya from India.
- Weed plants Cucumi smelo, Alternantherasessilis, Datura metal and Xanthium indicum were established as alternate hosts for PRSV.
Development of PRSV resistant papaya lines using transgenic approach
- A protocol for papaya tissue culture using immature embryos as explants material has been optimized with the aim to develop the genetically engineered papaya for Papaya ringspot virus resistance in papaya.
- Partial genomes of six isolates of Citrus Greening Bacterium (CGB) were sequenced and sequence deposited in NCBI GenBank (Accession No. JQ692599 to JQ692604).
- For management of aphid and psyllid vector on citrus, fortnightly sprays of acetemaprid (0.005%) in combination with neem oil (1%) was found most effective.
- Banana Streak Virus (BSV) was detected for the first time from India in the cultivar Kanchikela, genotype ABB by PCR. The sequence was deposited in NCBI GenBank (Accession No. JQ045128).Partial genome of 14 isolates of Banana Mysore streak and 21 isolates of Banana streak virus (Kerala) were sequenced and deposited in NCBI GenBank (Accession No. JQ858263 to JQ858276) and (Accession No. JQ911600 to JQ911619 and JQ346523) respectively.Combined incidence of BSV and Cucumber mosaic virus (CMV) was detected by PCR and ELISA respectively in banana cultivar kanchikela.
|A. Mixed infection of BSV and CMV, B. BSV, C. PCR detection of BSV
B. Vegetable crops:
- Zucchini yellow mosaic virus was reported for the first time from India in zucchini. Subsequently, the occurrence of this virus was also reported for the first time in India in other cucurbitaceous crops viz.muskmelon, bottlegourd, cucumber and sponge gourd.
|A. Symptoms of Zucchini yellow mosaic virus on zucchini and B. Virus particles
- First time report: Watermelon bud necrosis virus infection on muskmelon in India and in watermelon in Maharashtra.
- Occurrence of Groundnut bud necrosis Virus was reported for the first time in India on pumpkin, ash gourd and cucumber.
- Papaya ringspot virus-watermelon strain was recorded in sponge gourd for the first time in India.
- Potato virus Y was reported for the first time in drumstick (Moringaoleifera).
- Natural occurrence of two potyviruses viz. tobacco etch virus (TEV) and Pepper veinal mottle virus (PVMV) in polyhouse grown capsicum was recorded for the first time in Maharashtra.
- Management of Tomato Mosaic Virus, Groundnut Bud Necrosis Virus and Tomato Leaf Curl Virus:
- Seed treatment by soaking in 0.3% trisodium phosphate for 48 hours.
- Maize as border crop (about 75 cm height before transplanting of tomato seedlings in 4-6 rows).
- Cucumber as a trap crop (by sowing three weeks in advance after every 4 rows of tomato).
- One line of marigold after every ten lines of tomato.
- Foliar application of Neem seed kernel extract (10% freshly prepared) with alternate spray of dimethoate(0.05%) at 10 days intervals after transplanting.
DETECTION OF INVASIVE PEST
Occurrence of deadly pest South American tomato pin worm/leaf miner (Tutaabsoluta) was detected for the first time in the country. The pest was initially observed in Pune on tomato fields and in polyhouses during October 2014. The severe pest infestation (>50%) was observed in farmer’s fields in major tomato growing districts of Maharashtra viz., Ahmadnagar, Dhule, Jalgoan, Nashik, Pune and Satara. Subsequently, the pest alert has been issued in webpage of IARI and ICAR and in popular local Marathi newspaper.
|Figure: Tuta absoluta damaged tomato plants