Molecular genotypic diversity of populations of brinjal shoot and fruit borer, Leucinodes orbonalis and development of SCAR marker for pesticide resistance.

Palraju Murali,Karuppiah Hilda,Muthusamy Ramakrishnan,Sreeramulu Bhuvaragavan,Sundaram Janarthanan,Arumugam Ganesh

doi:10.1007/s11033-021-06791-2

Palraju Murali, Karuppiah Hilda + Show 4 more

Open Access

https://doi.org/10.1007/s11033-021-06791-2

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Abstract

The brinjal shoot and fruit borer, Leucinodes orbonalis is a destructive pest of Solanum melongena. The control of L. orbonalis with extensive application of synthetic chemical insecticides resulted in the development of resistance with known genetic heterogeneity among populations. Understanding the genetic diversity of their populations is important in developing strategies for their management. The present investigation was performed to characterize populations of L. orbonalis for their genetic diversity in the entire region of Tamil Nadu, South India using random amplified polymorphic DNA (RAPD) primers as a tool of the molecular marker. Among 60 random 10-mer primers, only ten primers generated reproducible and scorable banding profile. Among the ten different random primers, the primers namely OPG 7, OPG 8, OPS 2 and OPS 7 generated the highest genetic variation with over 80% genetic polymorphism. Phylogram analysis produced 18 clusters with eight major and ten minor clusters. Cluster analysis, statistical fitness, population structure and analysis of molecular variance confirmed the significant genetic variation among different populations. A trait specific marker obtained through RAPD was cloned, sequenced and used to develop a stable diagnostic SCAR marker for DNA fingerprinting to distinguish the populations. Amplification of this locus in the samples of 20 different populations indicated recognition of the trait for pesticide resistance in 12 populations. The results suggest that the biochemical nature of host plant varieties of this insect pest and variation in the application of different insecticides are essential contributing factors for the genotypic variations observed among populations of L. orbonalis.

Highlights

Brinjal, popularly known as eggplant (Solanum melongena L.) is a native vegetable crop of India and has been cultivated in the country for over 4000 years
The results suggest that the biochemical nature of host plant varieties of this insect pest and variation in the application of different insecticides are essential contributing factors for the genotypic variations observed among populations of L. orbonalis
PCR was carried out using sixty random random amplified polymorphic DNA (RAPD) primers on genomic DNA samples isolated from the larvae of L. orbonalis collected at twenty different locations in Tamil Nadu, South India

Summary

Introduction

Popularly known as eggplant (Solanum melongena L.) is a native vegetable crop of India and has been cultivated in the country for over 4000 years. The regular insecticide usage in a way helped L. orbonalis to be uncontrolled and having developed with genetic resistance via genotypic variations in their genome (Alyokhin et al 2008). This absolutely necessitates the molecular marker-based analysis to uncover the genotypic variations happening in the species population and to frame an effective plan under insect pest management programmes (Smith and Wayne 1996; Symondson and Liddell 1996). The present investigation was aimed to characterize populations of brinjal shoot and fruit borer, L. orbonalis for their genetic diversity throughout the entire region of Tamil Nadu (South India) using RAPD random primers as a tool of the molecular marker and further developing the suitable Sequence Characterized Amplified Region (SCAR) marker to identify the pesticide resistance population

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