# Genetic Diversity Analysis of 11 Macrobrachium rosenbergii Germplasms Based on Microsatellite Markers

## TL;DR

This study analyzed the genetic diversity of 11 Macrobrachium rosenbergii populations using new microsatellite markers, finding low diversity in Chinese populations and highlighting the need for better conservation and breeding strategies.

## Contribution

The study developed 20 new polymorphic microsatellite markers and provided baseline genetic data for Macrobrachium rosenbergii populations.

## Key findings

- Chinese Macrobrachium rosenbergii populations showed low genetic diversity compared to Southeast Asian ones.
- UPGMA clustering revealed that the Myanmar population was genetically distinct from others.
- The new microsatellite markers showed high polymorphism and can support future breeding and conservation efforts.

## Abstract

Examination of newly developed genetic markers of Macrobrachium rosenbergii showed low genetic diversity in Chinese populations as a whole, raising concerns about the broodstock sustainability, while some Southeast Asian populations remain more distinct. These findings highlighted the urgent need to protect and better manage prawn germplasm introducing diverse populations into broodstocks.

Macrobrachium rosenbergii is one of the largest and most economically significant freshwater prawns worldwide. Understanding its population genetic structure is essential for optimizing cross-breeding strategies, conserving germplasm resources, and supporting sustainable aquaculture. However, progress in this area has been hindered by the limited availability of reliable molecular markers. In this study, we developed 20 polymorphic microsatellite primer pairs and applied them to assess the genetic diversity of 11 populations collected from China and Southeast Asia (including Jiangsu, Zhejiang, Taiwan, Myanmar, Bangladesh, Sri Lanka, and Thailand). All loci exhibited high levels of polymorphism. The number of alleles (Na) ranged from 5 to 27, while the mean observed heterozygosity (Ho), expected heterozygosity (He), and polymorphism information content (PIC) were 0.570, 0.720, and 0.686, respectively. The genetic differentiation coefficient (Fst) among populations ranged from 0.017 to 0.289. UPGMA clustering revealed that the Myanmar population formed an independent branch, whereas the remaining ten populations clustered together, indicating relatively close genetic relationships among them. Beyond enriching the currently limited molecular marker resources for M. rosenbergii, this study provides essential baseline data for evaluating genetic diversity in existing populations and establishes a solid molecular foundation for future genetic monitoring and breeding programs.