on Canna sp. Panama, Chiriqui Province, Volcan, 8°46.421'N, 82°38.271'W, 25 Nov. 2004, leg. J.R. Hernandez 2004-097, II-III (BPI 864132). On Calathea sp. Panama, Veraguas Province, Los Ruices, 08°12.152'N, 81°30.521'W, 24 Nov. 2004, leg. J.R. Hernandez 2004-091, III. Panama, Chiriqui Province, Quebrada Cermeno, 08°29.997'N, 82°26.266'W, 28 Nov. 2004, leg. J.R. Hernandez 2004-141, II-III.
P. thaliae is widespread in the Americas as well as in Africa and Asia, reported on species in the Marantaceae and Cannaceae (Farr et al. 2004; Hernandez et al. 2005a, b). It has been reported from Panama on Calathea sp. (Kern 1938)asPuccinia cannae Henn. This is the firstreportof P. thaliae on Canna sp. from Panama.
Puccinia thaliae is the causal agent of canna rust, a fungal disease of Canna. Symptoms include yellow to tan spots on the plant's leaves and stems. Initial disease symptoms will result in scattered sori (clustered sporangia), eventually covering the entirety of the leaf with coalescing pustulates. Both leaf surfaces, although more predominant on the underside (abaxial) of the leaf, will show yellow to brownish spore-producing these pustulate structures, and these are the signs of the disease. Spots on the upper leaf-surface coalesce and turn to brown-to-black as the disease progresses. Infection spots will become necrotic with time, with small holes (3 to 5mm) developing in older leaves. These infected leaves eventually become dry and prematurely fall.[1]
When canna rust first appears, the affected foliage should be removed and discarded, otherwise the fungi will propagate and destroy the whole plant. The affected foliage should not be composted, as that will simply spread the fungus further.
Because canna rust thrives in warm, moist conditions (~20 °C), it is best to reduce irrigation or implement methods to reduce standing water, such as mulch and planting in the sun.
Commercially, a liquid copper-based spray can be sprayed on the stems and both sides of the leaves to prevent fungal problems before they occur. Although used commercially, copper is not recommended for home use because of its heavy metal toxicity.
Other practices include, reducing plant material or debris and reducing foliage from the plant. This practice can increase the aeration of the canopy, permitting more light and allowing fungicide sprays (if used) to reach the plant.[2] This method disrupts the uredospores stage from persisting.
Puccinia thaliae is a systemic pathogen, in that symptoms will affect a greater part or all of the plant.[3]
The disease cycle for canna rust has not been fully discovered, but there are several known pieces. Urediniospores (or uredospores), asexual rust spores, have been discovered on the leaf surface.[4] The color of the urediniospore can range from a golden to a yellow-orange, and are egg or pear shaped.[4] The uredospores are responsible for the spread of the rust to new leaf tissue. Uredospores are subglobose to ovoid or pyriform, echinulate, and measure 25.74 to 37.18 x 17.16 to 27.17 μm, with thickened walls apical walls (1.3 to 1.6 μm) and one to two equatorial germ pores. In addition, the overwintering spores that produce basidiospores, also known as teliospores, have been located on the leaf surface.[4] The teliospores range from cylindrical, clavate to club shaped, with rounded apex and sized from 50−83 × 14−21 μm.[5][4] Basidiospores are the sexual spores of rusts. There have been no pycnia or aecia located on Canna Rust.[4] However, P. thaliae has been known to cause rust on several cannabis species and on arrowroot which are other uredial hosts.[6] The pathogen is likely mobile in the plant leaf allowing it to spread across the leaf surface. The overwintering stage occurs during the wet and cold seasons.
The canna rust fungus grows best under high relative humidity and extended periods of leaf wetness (roughly ≥20 °C). This type of environment can be caused by high soil moisture, tall weeds surrounding the Canna, and dense shading that prevents moisture from evaporating from the leaf surface.[4] The fungus can survive in most tropical environments where the canna lily grows due to the tropics high relative moisture throughout the growing season.[4] P. thaliae has been reported throughout Europe and extends throughout the northern hemisphere.[7][8] In North America, P. thaliae has been reported to cause rust in Canna indica in Florida and C. × generalis in Texas. Also reported throughout Hawaii since the 1970s. The host range of P. thaliae includes Canna indica (syn. C. edulis) and some hybrids of C. × generalis and other plants of the order Zingiberales. Moreover, P. thaliae on Canna lily was reported in South Africa.[9][10]
Canna is a very versatile plant that has both ornamental and agronomic uses. In tropical parts of the world Canna achira, the agricultural breed of Canna, is grown for starch production in its rhizomes and fiber production in the shoots. Countries like Ecuador and Peru used to rely on Canna as a staple crop.[4] In Thailand Puccinia thaliae is listed as a medium threat to biosecurity and agriculture.[11] The Canna rust damages the crop and can impact all of its potential uses by damaging photosynthetic material and reducing plant productivity and value. In the United States it is a popular ornamental for home gardens. The rust lowers the value of lilies for sale and can kill canna plants that home gardeners are trying to grow themselves.
{{cite journal}}: CS1 maint: DOI inactive as of December 2022 (link) Puccinia thaliae is the causal agent of canna rust, a fungal disease of Canna. Symptoms include yellow to tan spots on the plant's leaves and stems. Initial disease symptoms will result in scattered sori (clustered sporangia), eventually covering the entirety of the leaf with coalescing pustulates. Both leaf surfaces, although more predominant on the underside (abaxial) of the leaf, will show yellow to brownish spore-producing these pustulate structures, and these are the signs of the disease. Spots on the upper leaf-surface coalesce and turn to brown-to-black as the disease progresses. Infection spots will become necrotic with time, with small holes (3 to 5mm) developing in older leaves. These infected leaves eventually become dry and prematurely fall.
Puccinia thaliae is een schimmel uit de familie Pucciniaceae, die op Canna-soorten voorkomy. De schimmel tast bij planten de bladeren en stengels aan.
Op de bladeren ontstaan geelachtige sporehoopjes, de uredinia, waarin de uredosporen gevormd worden. De uredinia kunnen zowel verspreid als samen geclusterd voorkomen op de bladeren. De goudkleurige uredosporen zijn 28 tot 40 micrometer lang en 20 tot 25 micrometer breed en de vorm varieert van eivormig tot peervormig.[1] Later in het seizoen worden er in de teleutosori teleutosporen gevormd.
Van oorsprong komt Puccinia thaliae voor in Noord-, Midden- en Zuid-Amerika. In de jaren vijftig en zestig van de twintigste eeuw bleek echter dat de schimmel zich verspreid had naar Nieuw-Caledonië en Indonesië. Vanaf de jaren zeventig komt de soort ook voor in de Amerikaanse staat Hawaï. Na 1981 werd echter bekend dat de schimmel zich verder verspreid had. De schimmel wordt nu ook aangetroffen in Zuidoost-Azië en dan specifiek in de landen China, India, Japan, Singapore, Taiwan en Thailand. In 1984 werd de schimmel ook waargenomen in Nigeria waarna de schimmel vervolgens in het jaar 2005 werd aangetroffen in Zuid-Afrika. Tevens zijn er monsters genomen van deze schimmel in het Pacifische gebied. In 2012 is de soort voor het eerst aangetroffen in Nieuw Zeeland.[2]
Puccinia thaliae is een schimmel uit de familie Pucciniaceae, die op Canna-soorten voorkomy. De schimmel tast bij planten de bladeren en stengels aan.
Puccinia thaliae je grzib[1], co go ôpisoł Dietel 1899. Puccinia thaliae nŏleży do zorty Puccinia i familije Pucciniaceae.[2][3] Żŏdne podgatōnki niy sōm wymianowane we Catalogue of Life.[2]
Wikispecies mo informacyje ô Puccinia thaliae.
Puccinia thaliae je grzib, co go ôpisoł Dietel 1899. Puccinia thaliae nŏleży do zorty Puccinia i familije Pucciniaceae. Żŏdne podgatōnki niy sōm wymianowane we Catalogue of Life.
