R. Nadakumar ¹, S. Babu ¹, A. Kandan ¹, T. Raguchander ¹, R. Samiyappan ¹

Affiliations
1 Department of Plant Pathology, Tamil Nadu Agricultural University, Coimbatore 641 003, Tamil Nadu, IN

Abstract

Eleven Pseudomonas isolates of ten-plant species collected from all over Tamil Nadu were compared for their total cell proteins separated through sodium dodecyl sulphate poly acrylamide gel electrophoresis. AH the isolates showed marked variations among themselves and between fluorescent and non-fluorescent groups. However, similarity was observed with respect to three protein bands with molecular weight of 46, 43 and 32kDa. Data were scored based on the presence or absence of protein bands and cluster analysis was performed. The isolates from same location viz., Coimbatore (PF1, PB2, COP1 and COT1), Sankaran Kovil (PSK1 and PSK2) and host (rice) showed greater level of similarity and occupied same cluster groups.

Keywords

Cell Protein, Electrophoresis, Pseudomonas, SDS-PAGE.

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Sandeep Singh ¹, Bonam Ramanujam ², Rajwinder Kaur Sandhu ², A. Kandan ², B. Poornesha ², Rupa Kundu ²

Affiliations
1 Department of Fruit Science, Punjab Agricultural University, Ludhiana – 141004, Punjab, IN
2 ICAR-National Bureau of Agricultural Insect Resources (NBAIR), Bengaluru – 560024, Karnataka, IN

Abstract

Surveys were conducted during 2017 and 2018 in the citrus orchards of Punjab, India to record the incidence of different insect pests and their natural enemies. During October-December, Entomopathogenic Fungus (EPF), Aschersonia aleyrodis was found to infect nymphs and pupae of citrus whitefly, Dialeurodes citri on the lower leaf surface of Kinnow from the orchards of Hoshiarpur, Ludhiana, Mansa and Fazilka districts.The fungus was isolated from the infected nymphs and pupae and morphological studies were conducted to confirm the identity of the entomopathogenic fungus. Aschersonia aleyrodis was reported for the first time on D. citri under Punjab conditions and this EPF also confirmed by amplification and sequencing of beta tubulin gene showed 99.40 per cent identity in NCBI, GenBank. Hence further studies on the host range, interaction with other insect pests and parasitoids, survival and longevity should be conducted to explore the potential of this fungus as microbial biocontrol agent for citrus whitefly.

Keywords

Aschersonia aleyrodis, biological control, citrus whitefly, entomopathogenic fungi, Punjab

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S. RUQIYA ¹, H. C. GIRISHA ¹, C. MANJUNATHA ², R. RANGESHWARAN ², A. KANDAN ², G. SIVAKUMAR ², M. K. PRASANNA KUMAR ³, D. PRAMESH ⁴, K. T. SHIVAKUMARA ², H. S. VENU ², S. NANDITHA ², K. S. ANKITHA ¹, K. ADITYA ², N. AARTHI ², S. N. SUSHIL ²

Affiliations
1 Department of Agricultural Microbiology, UAS, GKVK, Bengaluru – 560 065, Karnataka, IN
2 ICAR-National Bureau of Agricultural Insect Resources, Bengaluru – 560024, Karnataka, IN
3 Department of Plant Pathology, UAS, GKVK, Bengaluru – 560065, Karnataka, IN
4 Rice Pathology Laboratory ARS, Gangavathi, UAS Raichur – 584104, Karnataka, IN

Abstract

Bacillus subtilis  is  a Gram-positive and endospore producing bacterium. Limited studies have shown that lipopeptides produced by  B. subtilis  can be inhibitory to phytopathogens.   Sclerotinia sclerotiorum  is a plant pathogenic fungus  which causes  various diseases like cotton rot, watery soft rot, stem rot, crown rot and blossom blight in vegetable crops. The objective of the study was to isolate lipopeptides from  B. subtilis  and study their inhibitory potential against  S. sclerotiorum. So, the B. subtilis  isolates  were extracted from the collected soils of Western Ghats of India. They were initially characterized through morphological parameters followed by PCR amplification of the 16S rDNA gene and confirmation through BLAST algorithm in NCBI database. The lipopeptides produced by these isolates were tested against  S. sclerotiorum. B. subtilis  strains were effective against  S. sclerotiorum and exhibited 18.33 to 29.5 % inhibition under dual culture bio-assay. The antagonistic activity of lipopeptides extracted from  B. subtilis  strains showed 21.56 to 88.89 % inhibition of  S. sclerotiorum  in the lowest to highest concentration of lipopeptide tested and was found to be significantly higher than the control. The present study has shown that  B. subtilis  strains vary in the production of lipopeptides and some of them could produce lipopeptides that are highly inhibitory to S. sclerotiorum. B. subtilis  strain NBAIR BSWG1 showed the highest inhibition for S. sclerotiorum. Lipopeptide based poison food technique and the dual culture bioassay results showed that B. subtilis  strain NBAIR BSWG1 has immense potential for use in the biological control of  S. sclerotiorum. Further studies are being carried out in formulating the lipopeptides for field application.

Keywords

Antimicrobial property, biopesticide, PCR, soft rot of vegetable, Western Ghats.

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