Molecular Identification and Phylogeography of Invasive Cuscuta Species Infesting Alfalfa and Clover Crops

Abstract

Invasive species of Cuscuta represent serious parasitic weeds that threaten forage crop productivity by reducing plant vigor, nutrient uptake, and overall yield. Accurate identification and understanding of the geographical distribution of invasive Cuscuta species are essential for developing effective management strategies in alfalfa and clover production systems. The present study investigated the molecular identification and phylogeographic relationships of Cuscuta species infesting alfalfa and clover crops collected from different agricultural regions. Parasitic plant samples were collected from infested fields and subjected to morphological examination followed by molecular characterization using nuclear ribosomal ITS and chloroplast DNA markers. DNA amplification, sequencing, and comparative analysis were performed to confirm species identity and evaluate genetic diversity among populations. Phylogenetic analysis revealed the presence of genetically distinct invasive Cuscuta species associated with both host crops. The studied populations exhibited varying degrees of genetic similarity and geographical clustering, indicating possible regional adaptation and dispersal pathways. Certain haplotypes showed close evolutionary relationships with previously reported invasive populations from other regions, suggesting potential introduction and spread through contaminated seed materials or agricultural practices. The integration of molecular identification and phylogeographic analysis provided reliable insights into the evolutionary relationships and distribution patterns of invasive Cuscuta species. The findings contribute valuable information for early detection, quarantine measures, and integrated weed management programs aimed at minimizing the spread and economic impact of parasitic weeds in forage crop production systems.