Detection of Ageratum yellow vein China virus on weeds Acalypha indica L. and Euphorbia heterophylla L. in Indonesia

Begomoviruses are significant plant pathogens affecting various crops globally. Furthermore, weeds serve as reservoirs for these viruses, contributing to their spread and persistence. Field surveys in Sleman and Gunungkidul Regencies in Special Region of Yogyakarta, Indonesia, collected four Acalypha indica L. samples showing leaf cupping, mosaic, and stunting, and two Euphorbia heterophylla L. samples exhibiting chlorosis, mosaic, and stunting. Molecular detection and phylogenetic analysis revealed the presence of ageratum yellow vein China virus (AYVCNV) in all six samples based on the sequences of the partial AV1 gene. However, SPG1/SPG2 primers also showed that three isolates (katemas SMN1, katemas SMN2, and akar kucing SMN2) had recombinant sequences in the partial AC1-AC2 regions, with Ageratum yellow vein virus (AYVV) as one of the parent strains, indicating genetic exchange between both Begomovirus species. A scan using the Recombination Detection Program (RDP v5.30) confirmed strong signals in the three isolates, supporting the role of recombination in the evolution of begomoviruses. Two A. indica samples with systemic yellow vein clearing were also collected but tested negative using both primer pairs, indicating a different disturbance affecting them. This study molecularly characterized AYVCNV infecting A. indica and E. heterophylla for the first time in Indonesia and elsewhere. The findings highlight the importance of these widely distributed tropical weeds as alternative hosts for begomoviruses and underscore the need for continued monitoring to manage these viruses effectively in agricultural settings effectively.