First report of Puccinia thaliae on canna lily in New Zealand and in some Pacific island countries Mahajabeen Padamsee & Eric H. C. McKenzie Received: 4 July 2012 / Accepted: 15 August 2012 / Published online: 27 September 2012 # Australasian Plant Pathology Society Inc. 2012 Abstract A rust disease was observed on leaves of a culti- vated canna lily plant in Auckland, New Zealand in February 2012. Samples were collected and the causal agent determined by morphological and molecular techniques as Puccinia thaliae. This is the first record of P. thaliae in New Zealand. The rust is also reported for the first time from several countries in the Pacific islands. Keywords Ornamental plants . Pucciniales . Rust fungi Canna lily (Cannaceae) is a monocot, herbaceous pe- rennial ornamental plant that is native to tropical South America. Canna lily is a popular garden and landscap- ing plant in New Zealand and is also widely grown throughout the Pacific. In February 2012, a cultivated canna lily (Canna indica) growing in a residential gar- den in Auckland was found to be severely infected by a rust fungus. Subsequently, additional rust-infected canna lily plants were identified in Waiheke Island and other locations in Auckland. Samples were collected from the various locations and examined using light microscopy. Diseased samples from all locations exhibited similar symptoms of numerous, yellow, subepidermal, erum- pent, and circular to elliptical uredinia on both leaf surfaces. The sori were<1 mm in length, often about 0.25 mm diam. and scattered to clustered, covering the entire leaf. Initially the leaves were covered with ure- dinia but over the course of a month dark-coloured telia started to develop (Figs. 1–2). The urediniospores (Fig. 3) were variable in shape rang- ing from subglobose, ellipsoidal, obovoid to pyriform. They measured (23–)26–36(–43)×17–23(–27) μm (av. 30.8× 20.8 μm), with orange-yellow contents. The wall was thin (1–1.5 μm), hyaline and echinulate. The germ pores were obscure, but according to Sivanesan (1970) there are two equatorial pores. Initially, the compact, amber-coloured telia coalesced and developed in a circle around one or more uredinial pustules, mainly on the lower leaf surface but also on the upper surface. Later they were scattered on both sides of the leaf, circular, and <0.25 mm diameter. The teliospores (Fig. 4) were elongate-clavate with the lower cell being longer, narrower and paler than the upper cell. They mea- sured (50–)60–73(–80)×(13–)15–19(–21) μm (av. 65.7× 16.4 μm), with yellow-brown contents. The wall was smooth, yellow-brown, 0.75–1.5 μm thick at the sides and 1.5–4 μm at the apex, with an apical germ pore. The ped- icels were yellow-brown and up to 25×5.5–9 μm. Pycnia and aecia are not known for P. thaliae. The rust fungus was also examined by molecular methods. Sori were excised and DNA was extracted using an X-tractor Gene System (Corbett Life Science, NSW, Australia). The nuclear ribosomal large subunit (LSU) locus was amplified with a rust-specific primer Rust2inv (Aime 2006) and LR6 (Vilgalys and Hester 1990). A BLAST search of the LSU region returned two sequences of Puccinia thaliae (HQ434482 and EU851154) with 99 % sequence identity over 71 % and 100 % query coverage, respectively. DNA sequen- ces of three collections have been deposited in GenBank [JX206993 (PDD 102350); JX206994 (PDD 83149); JX206995 (PDD 82262)]. Until the late 1950s/early 1960s P. thaliae was known only from North, South and Central America (Anonymous 1969 ). It was then reported from Indonesia (Boedijn 1959 ) and New Caledonia M. Padamsee (*) : E. H. C. McKenzie Landcare Research, Private Bag 92170 Auckland, New Zealand e-mail: padamseem@landcareresearch.co.nz E. H. C. McKenzie e-mail: mckenziee@landcareresearch.co.nz Australasian Plant Dis. Notes (2012) 7:139–141 DOI 10.1007/s13314-012-0069-3