Puccinia spegazzinii (Pucciniales: Pucciniaceae) from Peru for biological control of Mikania micrantha (Asteraceae: Eupatorieae) in India: evaluating susceptibility of host populations and confirming host specificity

Abstract Mikania micrantha (Asteraceae: Eupatorieae), widely called mile-a-minute, has been a persistent problem to forestry, plantations and biodiversity conservation in southwestern and northeastern India, as well as in Andaman and Nicobar islands. To supplement the previously imported Trinidad-originating Puccinia spegazzinii (Pucciniales: Pucciniaceae), a different pathotype (IMI 393076) was imported from Peru, South America, after obtaining the import permit from the Plant Protection Advisor to the Government of India. The Peruvian pathotype was held in the National Containment-cum-Quarantine Facility for Transgenic Planting Material at ICAR–National Bureau of Plant Genetic Resources in New Delhi as a quarantine organism for pre-release evaluation. Screening of M. micrantha populations from Andaman and Nicobar islands (12), Assam (15) and Kerala (3) indicated their complete susceptibility to the Peruvian pathotype. In the host-specificity tests, the rust could not infect any of the 25 plant species in ten tribes within Asteraceae, which confirmed its safety to non-target plant species. Further, none of the 31 sunflower cultivars/accessions screened were infected