Induction of defence-related proteins by selected plant growth regulators and biocontrol agents against guava root knot nematode, Meloidogyne enterolobii

N Ashokkumar; K Poornima; P Kalaiarasan; P Jeyakumar; D Uma; M Kavino; S Dharani; S Kothai

doi:10.21307/jofnem-2021-081

Induction of defence-related proteins by selected plant growth regulators and biocontrol agents against guava root knot nematode, Meloidogyne enterolobii

J Nematol. 2021 Oct 6:53:e2021-81. doi: 10.21307/jofnem-2021-081. eCollection 2021.

Authors

N Ashokkumar¹, K Poornima², P Kalaiarasan², P Jeyakumar³, D Uma⁴, M Kavino⁵, S Dharani², S Kothai¹

Affiliations

¹ College of Agricultural Sciences, SRM Institute of Science and Technology, SRM Nagar, Kattankulathur, Tamil Nadu, India, 603203.
² Department of Nematology, Agricultural College and Research Institute, Tamil Nadu Agricultural University, Coimbatore, India.
³ Department of Crop Physiology, Agricultural College and Research Institute, Tamil Nadu Agricultural University, Coimbatore, India.
⁴ Department of Biochemistry, Agricultural College and Research Institute, Tamil Nadu Agricultural University, Coimbatore, India.
⁵ Department of Fruit Science, Horticultural College and Research Institute, Tamil Nadu Agricultural University, Coimbatore, India.

Abstract

Guava is an important edible and economic fruit crop distributed worldwide. It is widely infested with root knot nematode, Meloidogyne enterolobii which plays a vital role in causing economic losses. Several management strategies were performed to enhance the health status of guava and also to reduce root knot nematode infestation. Among the different aspects, application of plant growth regulators on guava plants under nursery conditions against root knot nematode, M. enterolobii was performed. The guava plants were treated with Salicylic acid (100 ppm), Jasmonic acid (100 ppm), and Indole 3-Butyric Acid (1000 ppm) alone and in combination of two and three. The result of this study revealed that IBA at 1,000 ppm alone (T3) and combined application of plant growth regulators viz., (T₄) - Salicylic acid (100 ppm) + Jasmonic acid (100 ppm) + Indole 3-Butyric Acid (1,000 ppm) showed reduction in the nematode population and establishment of new roots (compensatory) and tertiary roots. The combined application of PGRs also increased the Plant height, root length, chlorophyll index, photosynthetic rate, transpiration rate, stomatal conductance, and chlorophyll fluorescence. The activity of various enzymes like total phenols, peroxidase, polyphenol oxidase, acid phosphatase, and phenylalanine ammonia lyase were influenced and developed resistance against root knot nematode, M. enterolobii. Under field conditions, application of Pochonia chlamydosporia and Purpureocilium lilacinum reduced the nematode infestation besides increasing the yield attributes of guava plants.

Keywords: Bioagents; Guava; Meloidogyne enterolobii; Plant growth regulators.