Aqueous fruit extracts of Azadirachta indica induce systemic acquired resistance in barley against Drechslera graminea

Abstract

The study reported here primarily focuses on whether fruit extracts of Azadirachta indica Juss. (Neem) can induce systemic acquired resistance (SAR) in Hordeum vulgare against Drechslera graminea. A single leaf from each of the 1-month-old seedlings grown in 50 pots was treated with neem extract. Seven samples were collected at 12-h intervals for estimation of salicylic acid (SA) content and activities of phenylalanine ammonia lyase (PAL) and peroxidase (PO). Disease incidence was recorded on uninoculated leaves after 2 weeks and on newly emerged leaves after 3 weeks of inoculation of spores of the pathogen. Treatment of single leaf of barley seedlings with aqueous fruit extract of neem could protect the untreated and later emerging leaves of these seedlings from infection by leaf stripe pathogen. The concentration of SA and activities of PAL and PO were significantly higher in untreated leaves of seedlings given a single leaf treatment with neem fruit extract. The results show that neem fruit extract induced SAR in barley seedlings against D. graminea. The results of the study are significant for developing an environment-friendly biocide, which could induce SAR in crop plants leading to efficient management of pathogens

Keywords:

• Azadirachta indica
• Drechslera graminea
• systemic acquired resistance
• salicylic acid
• phenylalanine ammonia lyase
• peroxidase

Acknowledgement

The authors are thankful to Amity University, Uttar Pradesh, for providing necessary infrastructural facilities.