Polymorphisms in the hypervariable control region of the mitochondrial DNA differentiate BPH populations

Area of Science:

• Agricultural Entomology
• Molecular Ecology
• Population Genetics

Background:

• The brown planthopper (BPH), *Nilaparvata lugens*, is a major rice pest in India, causing significant crop losses due to its migratory nature.
• Understanding BPH population dynamics is crucial for developing effective management strategies, but reliable markers for assessing diversity are limited.

Purpose of the Study:

• To develop novel molecular markers for assessing genetic diversity within and among Indian BPH populations.
• To utilize polymorphisms in the mitochondrial Control Region and nuclear genomic simple sequence repeats (gSSRs) for population differentiation.

Main Methods:

• PCR amplification, cloning, and sequencing of the BPH mitochondrial Control Region from nine populations.
• Development and application of three genomic simple sequence repeat (gSSR) markers.
• In silico analysis of restriction fragment length polymorphisms (dRFLPs) using HpyCH4IV and Tsp45I enzymes on Control Region sequences.

Main Results:

• Extensive polymorphism was observed in the mitochondrial Control Region, attributed to variable numbers of tandem repeats.
• gSSR markers showed population-specific amplification patterns, indicating genetic differentiation.
• High overall genetic diversity (>5%) was found among the nine BPH populations.
• Digital-RFLPs derived from the Control Region successfully differentiated all nine BPH populations.

Conclusions:

• Novel markers from the BPH mitochondrial Control Region and gSSRs provide valuable insights into population structure and diversity.
• The developed markers, particularly dRFLPs from the Control Region, offer a rapid and reliable method for differentiating BPH populations.
• This research lays the foundation for targeted and efficient pest management strategies based on precise population identification.