Deconstructing the evolutionary complexity between rust fungi (Pucciniales) and their plant hosts

The rust fungi (Pucciniales) are the most speciose natural group of plant pathogens, members of which possess the most complex lifecycles in Fungi. How natural selection works on the Pucciniales has been the subject of several hypotheses in mycology. This study uses molecular age estimation using sequence data from multiple loci, and cophylogeny reconciliation analyses to test hypotheses regarding how the aecial and telial stages in the lifecycle of rust fungi may have differentially impacted their diversification. Molecular age estimates show that the timing of diversification in the Pucciniales correlates with the diversification of their gymnosperm and angiosperm hosts. Host reconciliation analyses suggest that systematic relationships of hosts from the aecial stage of the Pucciniales lifecycle better reflect the systematic relationships among the Pucciniales. The results demonstrate the relative importance of this stage on the overall evolution of the Pucciniales and supports hypotheses made by Leppik over half a century ago. This study represents the first evaluation of how different life stages in the Pucciniales shape the evolution of these fungi. Key words: Basidiomycota, Biogenic radiation, Biological specialization, Hologenetic ladder hypothesis, Melampsorineae, Phytopathogenic fungi, Pucciniaceae, Pucciniomycotina, Uredinale

Names of Phytopathogenic Fungi: A Practical Guide

Using the correct name for phytopathogenic fungi and oomycetes is essential for communicating knowledge about species and their biology, control, and quarantine as well as for trade and research purposes. However, many plant pathogenic fungi are pleomorphic, meaning they produce different asexual (anamorph) and sexual (teleomorph) morphs in their life cycles. Therefore, more than one name has been applied to different morphs of the same species, which has confused users. The onset of DNA technologies makes it possible to connect different morphs of the same species, resulting in a move to a more natural classification system for fungi in which a single name for a genus and species can now be used. This move to a single nomenclature, coupled with the advent of molecular systematics and the introduction of polythetic taxonomic approaches, has been the main driving force for a reclassification of fungi, including pathogens. Nonetheless, finding the correct name for species remains challenging. In this article we outline a series of steps or considerations to greatly simplify this process and provide links to various online databases and resources to aid in determining the correct name. Additionally, a list of accurate names is provided for the most common genera and species of phytopathogenic fungi

New records of Puccinia helianthi Schw. на Cyclachaena xanthiifolia (Nutt.) Fresen. from Ukraine

In September 2012 a rust fungus on Cyclachaena xanthiifolia was recorded in two localities near Odessa, Ukraine (46°0' N, 29°40' E and 46°25' N, 30°10' E). Sequences of the 28S subunit of the nuclear ribosomal DNA show that the rust on C. xanthiifolia is conspecific with Puccinia helianthi. Ukraine is apparently the only country outside of the USA from which P. helianthi has been noted on C. xanthiifolia.У вересні 2012 р. у двох локалітетах на території Одеської обл. (46°0' N, 29°40' E і 46°25' N, 30°10' E) відзначено розвиток іржастого гриба на Cyclachaena xanthiifolia. Послідовності субодиниці 28S ядерної рибосомальної ДНК підтвердили належність гриба на C. xanthiifolia до виду Puccinia helianthi. Вірогідно, Україна — єдина, крім США, країна, де P. helianthi зареєстрована на C. xanthiifolia.В сентябре 2012 г. в двух локалитетах на территории Одесской обл. (46°0' N, 29°40' E и 46°25' N, 30°10' E) отмечено развитие ржавчинного гриба на Cyclachaena xanthiifolia. Последовательности субъединицы 28S ядерной рибосомальной ДНК подтвердили принадлежность ржавчинника на C. xanthiifolia к виду Puccinia helianthi. Повидимому, Украина является единственной, кроме США, страной, где P. helianthi зарегистрирована на C. xanthiifolia