Pathotypes of Melampsora rust on Salix in short‐rotation forestry plantations

Abstract

Melampsora epitea , the causal agent of leaf rust on willow ( Salix spp.) in short-rotation forestry, was sampled over four consecutive years (1993 -96) in Sweden. The pathotype patterns of 332 single-spore isolates were examined for virulence characteristics using a defined set of willow hosts. Thirty-seven pathotypes of M. epitea were identified and grouped into three formae speciales . No race or morph subdivision was observed among the isolates, other than the three formae speciales . For monitoring and studying the ecological and evolutionary dynamics of virulence for M. epitea , an internationally useful naming system for pathotypes is proposed, with a three-digit code referring to virulence on a specified set of standard test clones.

Comparing Chilean and Swedish rust populations: possible impact of long‐distance transport of Melampsora rust

“…75%) pathotypes were different from Chilean pathotypes (Ramstedt et al 2002), whereas for Chile, the percentage was lower with 14 (approx. 75%) pathotypes were different from Chilean pathotypes (Ramstedt et al 2002), whereas for Chile, the percentage was lower with 14 (approx.…”

“…Exceptions were, for example, the isolates collected from S. humboldtiana (the indigenous species of Chile) for which the majority (12 of 20 isolates) was incompatible with all test clones in the differential ( Table 2). 1) than in Sweden (Ramstedt et al 2002), even if a few pathotypes seemed to dominate the Chilean rust collection. Most of these inoculations succeeded in causing disease symptoms, which were especially strong for S. viminalis clones.…”

“…Using a set of nine willow clones (willow-differentials) (Table 1), 89 Melampsora rust isolates were pathotyped according to Ramstedt et al (2002). As controls for viability of the rust spores, nine ÔChileanÕ willow clones were used (Table 1).…”

“…As controls for viability of the rust spores, nine ÔChileanÕ willow clones were used (Table 1). The Ôpathotype codeÕ assigned to an isolate was based on the combination of infected clones, according to Ramstedt et al (2002) ( Table 1). For inoculation, willow leaves were placed on wet filter paper in Petri dishes or in plastic boxes and then sprayed with a suspension of 5 lg of dry spores in 14 ml distilled water with a drop of Tween 20 added.…”

Melampsora rust species on biomass willows in central and north-eastern Germany

“…In the past, the distinction of Melampsora species relied on spore morphology and determination of host species (G€ aumann 1959;Klebahn 1903Klebahn , 1904Pei et al 1993). Below the species level, inoculation tests with aeciospores and uredospores were used to differentiate formae speciales (Klebahn 1904;Pei et al 1996;Ramstedt et al 2002;Schneider 1906). First proposed to subdivide cereal rusts of the genus Puccinia (Eriksson 1894), the concept of formae speciales is widely used to distinguish fungal pathogens that have the same morphology but colonize different hosts within sharply circumscribed host ranges (Anikster 1984;Reignault & Sancholle 2005;Schulze-Lefert & Panstruga 2011).…”