The presence of Austropuccinia psidii and the threat to Myrtaceae plantations in Indonesia

Abstract

Austropuccinia psidii is an invasive pathogenic rust that infects the Myrtaceae family. This rust is a threat to Myrtaceae plantations around the world due to its widespread distribution. In this study, we observed the presence of A. psidii in three species of Myrtaceae, i.e. Melaleuca cajuputi, Syzygium myrtifolium, and Syzygium polyanthum planted in Yogyakarta and Sukabumi. The symptoms of infection were yellow-reddish spot in young leaves, presence of urediniospores in infected spot, foliage, and branch dieback. To confirm the presence of A. psidii on those trees, a molecular detection was performed using specific primer for A. psidii (Ppsi1/Ppsi6) on DNA samples extracted from diseased leaves. The presence of A. psidii was proved by the presence of DNA amplicon sized around 500bp in all samples collected from three different hosts. In this study, S. myrtifolium was firstly reported to be infected by this rust in Indonesia. Further study about the presence and the economic impact of this pathogen in Indonesia should be conducted. Indonesia has many species numbers of Myrtaceae and some species are important for medicines, herbs, foods, and as industrial plants. A strategy to control this pathogen should be established to avoid large economic losses in Myrtaceae plantations in Indonesia.