Phragmidium rosae-multiflorae on Rosa multiflora reported from Pennsylvania, USA

Area of Science:

• Mycology
• Plant Pathology
• Invasive Species Ecology

Background:

• Multiflora rose (Rosa multiflora) is an invasive shrub in North America, introduced from East Asia.
• The plant's rapid growth and ability to outcompete native species highlight the need for effective control measures.
• Fungal pathogens can serve as biocontrol agents for invasive plants.

Purpose of the Study:

• To report the first confirmed occurrence of Phragmidium rosae-multiflorae (rose rust) in North America.
• To document the morphological and molecular characteristics of the identified fungus.
• To assess the significance of this finding for the management of invasive multiflora rose.

Main Methods:

• Field collection of infected Rosa multiflora in Patton Township, PA, USA.
• Morphological characterization of fungal aecia and aeciospores.
• DNA extraction from infected plant tissue, PCR amplification, and sequencing of the 28S ribosomal DNA region.

Main Results:

• First North American record of Phragmidium rosae-multiflorae on Rosa multiflora.
• Morphological features of aecia and aeciospores consistent with P. rosae-multiflorae.
• DNA sequence analysis showed 98.77% identity to a Chinese isolate of P. rosae-multiflorae.

Conclusions:

• The presence of Phragmidium rosae-multiflorae in North America is confirmed.
• This rust fungus represents a potential biological control agent for invasive multiflora rose.
• Further research is warranted to evaluate its efficacy and ecological impact as a biocontrol agent.