Mixed Infection of Mungbean yellow mosaic India virus and ‘Candidatus Phytoplasma aurantifolia’ (16SrII-A) in Mung Bean and Yard Long Bean in Nganjuk Regency, East Java Province, Indonesia

Abstract

Mungbean yellow mosaic India virus (MYMIV, Begomovirus vignaradiataindiaense, Genus Begomovirus) is well understood to incite chlorosis on mung bean (Vigna radiata) and yard long bean (V. unguiculata ssp. sesquipedalis). However, presence of the virus in mung bean in Indonesia has not been studied. Furthermore, leaf deformation symptoms, typical of phytoplasma disease, are also observed occasionally on both horticultural species. In February 2025, two yard long bean and two mung bean samples showing chlorosis, mosaic, and small leaf as well as non-symptomatic yard long bean and mung bean, one sample respectively, were collected in Nganjuk Regency, East Java Province. The samples were tested by PCR using Krusty/Homer and SPG1/SPG2 universal primers for begomoviruses, and the nested R16mF2/R16mR2 and R16F2n/R16R2 universal primers for phytoplasmas detection. One mung bean (no. 119) and one yard long bean (no. 419) were shown to be mixed-infected by begomovirus and phytoplasma. One mung bean (no. 219) was positive for phytoplasma only. One yard long bean (no. 519) and both non-symptomatic samples (no. 319 and 619) were negative for both pathogens. BLAST and phylogenetic analyses demonstrated that both begomovirus isolates are MYMIV, and the three phytoplasma strains are associated with the ‘Candidatus Phytoplasma aurantifolia’ (16SrII-A group, peanut witches'-broom). This research reported the first occurrences of MYMIV in mung bean and mixed infection of MYMIV and phytoplasma in mung bean and yard long bean in Indonesia, to the best of our knowledge. Further surveys are necessary to study both pathogens distribution among legumes in the country.