Electron Beam Irradiated Chitosan elicits enhanced antioxidant properties combating resistance to Purple Blotch Disease (Alternaria porri) in Onion (Allium cepa).

Abstract

Purpose

This study was carried out to assess the effect of irradiated chitosan as an elicitor on the biochemical traits associated with resistance to purple blotch disease in onion.

Materials and methods

Chitosan was electron beam irradiated at 100 kGy dose to obtain low molecular weight chitosan. Irradiated chitosan at 20 and 0.04% concentration and different time intervals was used as a biological elicitor cum antimicrobial agent against purple blotch disease in onion. Field grown onion (Variety Basanvant 780) plants were foliar sprayed with irradiated chitosan and the biochemical responses were monitored using parameters namely chlorophylls, carotenoids, antioxidant enzymes, phenols, and antifungal enzyme β-1,3 Glucanase using standard methods.

Results

Compared to control treatment, a positive correlation with irradiated chitosan treatment was observed for an increase in β-1,3-glucanase, peroxidase activity, and contents of total phenolics, chlorophylls, and carotenoids, which cumulatively contributed to resistance response against the purple blotch disease. Irradiated chitosan (0.04%) treated onion plants at 30, 45, and 60 DAT showed a higher total phenolics, β-1,3-glucanase activity, and peroxidase activity besides enhanced antioxidant properties.

Conclusion

The results suggest that irradiated chitosan has elicited resistance responses against purple blotch disease in onion. The increased production of antioxidant metabolites may provide value addition to onion as a food commodity.

Keywords:

• Onion
• Allium cepa
• Alternaria porri
• irradiated chitosan
• induced disease resistance
• electron beam irradiation

Acknowledgments

The authors are thankful to Director, VSI, Pune for providing the material, Staff of EBC-Kharghar, BARC, Mumbai for providing irradiation facilities, Head, Department of Plant Pathology and Department of Biochemistry, MPKV, Rahuri, field and laboratory facilities.

Disclosure statement

The authors declare that there is no conflict of interest with this manuscript.

Additional information

Funding

This work was supported by Board of Research in Nuclear Sciences, Mumbai (India) &; Mahatma Phule Krishi Vidyapeeth, Rahuri.

Notes on contributors

Harshvardhan Dattatray Gaikwad

Harshvardhan Dattatray Gaikwad is a  postgraduate research student, who contributed conducting research experiment, data collection and preparation of manuscript.

Sunil Govind Dalvi

Sunil Govind Dalvi is a Scientist at VSI, Pune, who contributed for the development of irradiated chitosan, experimental planning, data collection, data analysis and manuscript preparation.

Shrihari Hasabnis

Shrihari Hasabnis is an Associate Professor at the College of agriculture, Pune, who contributed for planning experiment, executing experiment, data analysis and interpretation of results.

Penna Suprasanna

Penna Suprasanna is an Ex-Head, Nuclear Agri. Biotechnology Div, BARC Mumbai, who contributed for irradiation of material, manuscript preparation, data analysis and data interpretation.