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Puccinia menthae teliospores : apical cell length versus basal cell length, peppermint rust (j), spearmint rust (#).
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Puccinia menthae is highly variable, with several varieties and variants within varieties. Two principal groups of races, nominated spearmint rust and peppermint rust, have been recognized according to their host range on commercially-important Mentha species, yet both belong to the same variety, P. menthae var. menthae. Ten collections of P. menth...
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... length and width, although there was significant variation between isolates within groups for these characters. The covariance analysis (Table 3) failed to show any relationship between apical and basal cell length, either within group (model 2) or overall (model 1). The individual measurements overlap, but the group means are clearly different (Fig. 3). There was, however, a highly significant relationship between apical and basal cell widths and the slopes were significantly different between the two groups (Fig. 4). For spearmint rust the fitted regression equation was : apical cell width l 8n23j0n611 basal cell width, while for peppermint rust the equation was : apical cell width ...
Citations
... To our knowledge, this is the first report of Puccinia menthae causing leaf rust on Mentha spicata in Mexico. This species has been previously identified in Australia (Edwards et al. 1999), New Zealand (Beresford et al. 1982), and USA (Farr and Rossman, 2021) on Mentha spicata. This disease reduces considerably the quality of peppermint plants, so it is necessary to develop management strategies. ...
Spearmint (Lamiaceae) is an aromatic herb widely cultivated in Mexico for its culinary, medicinal, and industrial properties. In May 2020, symptoms and signs of rust were observed in a two-ha commercial crop of spearmint in Cuautla, Morelos (18°50'26.6"N 98°57'31.9"W), Mexico. The disease incidence was 85% and the severity was 23%. Initial symptoms included chlorotic spots on the adaxial surface of the leaves. At advanced stages of the disease, necrotic spots surrounded by chlorotic halos were developed, and later the plants were defoliated. The signs were observed as numerous orange to reddish-brown
... Our result revealed the lack of spermogonia and aecia in P. menthae and P. exhausta recorded on M. longifolia and C. grata, respectively is similar to that observed by Edwards et al. (1999) and by using microscopic, molecular and SEM techniques in their examination. Like our study, it also comprehended Uredinia on the abaxial side, Uredeniospores ovoid, globose and ellipsoid in shape Telia was amphigenous, scattered in cluster form, elongate, smallest to largest, and pulverulent brown to black. ...
Rusts comprises the largest natural group of plant pathogens including approximately 8% of all described Fungi. Rust fungi are extremely plant pathogens responsible for great losses to agriculture productivity. Rust species belong to several genera among which more than half are Puccinia species. In Pakistan, rust causes severe damage to agriculture crops. Current study was carried out to identify and characterize different rust species common in the research area through microscopy and Scanning electron microscopy (SEM) in Khyber Pakhtunkhwa, Pakistan. Morpho-anatomical investigation of each collected rust species was carried out using different standard protocols. The dimensions of spores were measured and snapped under a stereomicroscope. SEM was used to examine the shape, size, and ornamentation of the spores of each rust fungus. Results revealed documentation of seven rust fungi, that is, Melampsora euphorbiae, Phragmidium barclayi, Puccinia nepalensis, P. exhausta, P. menthae, Uromyces capitatus, and Uromyces decorates belong to four different genera, were recorded. SEM revealed that spermogonia and Aecia were missing in most of the rust fungus studied. Uredinia was found in a scattered, irregular, lengthy, and epidermis-enclosed form. Urediniospores were found to be ovulating, elongated, echinulate, globose to sub-globose, ellipsoid to ovoid, and globose to sub-globose. Telia was found as sub-epidermal, amphigenous, dispersed, minute, and spherical cells. Teliospores ranged in form from cylindrical to oblong. The germ pores were detected in both apical (top cell) and basal (bottom cell) idiosyncratic and pedicel-attached cells. The techniques used in the current investigation will aid mycologists in rust identification and microscopic characterization.
... In some species of the genus Puccinia, different virulence phenotypes, physiologic specialization or rust strain correlation with host reactions have often been reported (Edwards et al. 1999;Kolmer and Liu 2000;Asnaghi et al. 2001;Villareal et al. 2002). Positive correlations between genetic diversity and geographic distance have been reported for some fungus isolates, while other isolates have been found to lack this correlation (Mebrate et al. 2006;Cardona Giraldo 2008). ...
AFLP analysis was carried out to assess genetic variability and determine the population structure of the sugarcane rust Puccinia melanocephala in northwest Argentina. Molecular data were also used to clarify whether genetic variation was correlated with host variation and/or the geographic distribution of the disease. Bulk rust uredospores were collected in the field, and both the geographical area and the infected host sugarcane cultivar were recorded. A total of 538 AFLP markers generated with 20 primer combinations were used to perform the genetic analysis. The percentage of polymorphic loci was quite high (85.7%), considering that P. melanocephala only reproduces asexually. Cluster analysis (UPGMA) and principal co-ordinate analysis (PCoA) grouped populations from distinct geographic and host origins, suggesting that neither geographical region nor sugarcane variety constrains the relationships among the populations. This finding was corroborated by a lack of significant correlation between genetic distance and geographic distance (r = 0.057; P = 0.285). The non-significant differences found between rust populations collected from distinct sugarcane varieties (PhiT = 0.026; P = 0.06) also support these results. Analysis of Molecular Variance Approach (AMOVA) analysis attributed most of the variation (95%) to differences within populations. No genetic structure was detected, and the populations behaved as a large undifferentiated population with high level of genetic variability.
... Recently, molecular methods have been developed to clarify genetic variation and phylogenetic relationships of rust fungi Vogler and Bruns 1998;Edwards et al. 1999;Newcombe et al. 2000;Ayliffe et al. 2001;Virtudazo et al. 2001;Hantula et al. 2002;Maier et al. 2003;Weber et al. 2003). The purpose of this study is to analyze morphological characteristics and phylogenetic relationships of Melampsora species on poplars in China, including M. larici-populina, M. laricis, M. magnusiana (ϭM. ...
Many species of Melampsora on Populus have been reported in China, based on morphological characteristics of both uredial and telial states, and on host species, but their morphology and taxonomy are still poorly defined. In this study, 196 specimens representing Melampsora species on poplars and collected from various areas of China were used for morphological observations. The morphological characteristics of urediniospores and teliospores were examined with light and scanning electron microscopy. The specimens could be classified into five groups based on their morphology. For the sequencing of the nuclear large subunit rDNA (D1/D2), 5.8S rDNA and their internal transcribed spacers, ITS1 and ITS2 region, 54 specimens were selected from the specimens used in morphological observations. These specimens were separated into six clades by phylogenetic analyses of the D1/D2 and ITS regions. Correlations among morphological groups and phylogenetic clades based on these results suggest a revision of these species. In particular, no evidence to discriminate specimens of M. acedioides, M. magnusiana, and M. rostrupii was found from either morphological characteristics or sequence analysis.
... Only distinct, unambiguous bands were scored. Simple matching coefficients (SMC) (Sneath & Sokal 1973) were calculated using a program previously used for mint rust (Edwards et al. 1999). A genetic dissimilarity measurement was then calculated as 1-SMC, which is equivalent to squared euclidian distance between the isolates. ...
Mycosphaerella contains some of the most damaging foliar pathogens of Eucalyptus. Identification of the species has relied mainly on characters such as ascospore morphology and the mode of ascospore germination. Wide variation and overlap in morphological characters, especially ascospore shape and size, has lead to confusion in species concepts. This study examines the potential of RAPD-PCR to differentiate Mycosphaerella species that cause leaf diseases of Eucalyptus in Australia. RAPD-PCR was conducted on 39 isolates representing 10 species of Mycosphaerella collected from southern Australia. Primers were chosen mainly to distinguish between the two most common and damaging species in Australia, M. cryptica and M. nubilosa. The RAPD analysis revealed five groups within the 39 isolates, four of which represent distinct species: M. cryptica, M. gregaria, M. nubilosa and M. marksii. For these four species, the cluster analysis and RAPD patterns gave results that fitted well with classical taxonomic criteria. Variation within M. cryptica, M. nubilosa and M. marksii was low, even though the isolates within these species originated from diverse hosts and locations. The remaining species in this study grouped together and could not be easily separated using the RAPD data here.
It is necessary to evaluate the variety samples of the crop to obtain the parental material of menthol mints, which will have a high content of essential oil, and be less affected by various diseases. We evaluated the variety samples of mint for disease resistance at the Voznesenskaya branch of V.S. Pustovoit of All-Russian Research Institute of Oil Crops. In the conditions of the branch in the piedmont area of the Western Ciscaucasia, there were identified diseases such as powdery mildew, rust, anthracnose and Fusarium blight. The studied variety samples were characterized by varying degrees of resistance to these diseases. The most harmful disease for mint is rust, the pathogens of which are the Puccinia menthae Pers. and P. angustata Peck. We identified the parental material for development a variety of peppermint Rozovskaya Aroma by analyzing the variety samples of menthol mint for three years of vegetation. Also, we developed and applied the modified scale for evaluation of resistance to the main diseases for the menthol forms of mint.
This study is focused on macrocyclic, heteroecious grass rusts (Pucciniales) with the aecial stage on Ranunculus spp. and Ficaria verna. Our aim is to study their phylogeny and host range, and evaluate differentiating morphological and molecular markers. Phylogenetic analyses of ITS-LSU rDNA recognised Puccinia perplexans, P. magnusiana, Uromyces dactylidis, U. poae, and three other lineages of uncertain taxonomic classification (U. cf. festucae and Uromyces species having aecia on Ranunculus). We showed that U. poae complex is a sister to U. dactylidis and belongs to the single clade with P. perplexans, phylogenetically distant from P. magnusiana. Of the PCR fingerprinting methods tested for species differentiation, only ISSR-PCR was found to be suitable. The analysis supported classical morphology-based taxonomic concepts of the species. Ficaria verna and Ranunculus acris were found to be the exclusive hosts of U. poae and P. perplexans, respectively. Ranunculus repens hosted U. dactylidis, P. magnusiana and an unidentified taxon from the U. poae clade. No specific differential features were found in aeciospore ornamentation, and only Uromyces cf. festucae can be distinguished based on specific aecial morphology. Based on aeciospore dimensions, only two species, U. dactylidis and P. perplexans, cannot be distinguished. All other species, including sister species U. poae and U. dactylidis, showed statistically significant differences. Because of overlapping morphological features of aecia and aeciospores, the molecular characters are necessary for their determination.
Urediniospores were collected separately from rust pustules on oregano (Origanum vulgare) and spearmint (Mentha spicata) plants purchased from retail stores in Gainesville, Alachua Co., FL, in April 2004 and March 2005. Morphological characteristics of the urediniospores from both hosts were consistent with descriptions of Puccinia menthae. Spearmint, peppermint (M. × piperita), oregano (O. vulgare), sweet marjoram (O. majorana), and Greek oregano (Oregano heracleoticum) were inoculated with urediniospore suspensions of each rust isolate in a series of cross-inoculation experiments. Rust developed on oregano, sweet marjoram, and Greek oregano only when inoculated with urediniospores from the oregano plant, and this rust isolate did not infect any of the Mentha spp. tested. Rust developed on spearmint when inoculated with urediniospores from the mint plant, but this isolate did not infect peppermint, oregano, sweet marjoram, or Greek oregano. The two isolates of Puccinia menthae appear to represent different populations, “spearmint rust” and “oregano rust.” This is the first report of P. menthae on oregano in Florida.
Accepted for publication 2 March 2006. Published 17 April 2006.
Preliminary investigations into the diversity of Puccinia boroniae, collected from across southern Western Australia, were conducted by morphological comparison of the teliospores derived
from host species Boronia heterophylla and Boronia megastigma, and by restriction enzyme profiling of the internal transcribed spacer (ITS) region of the nuclear rRNA (rRNA) genes of
21 isolates from a variety of different Boronia species and cultivars. Assessment of teliospore morphology provided significant evidence of two distinct rust groups, separated
on the basis of their host plant origin. In general, teliospores from Boronia heterophylla had wider apical and basal cell widths, thinner cell walls and apical papilla, than those isolated from Boronia megastigrna. Restriction analysis of the ITS region provided no evidence of intraspecific variation among the 21 isolates; however, one
isolate, distinct from the screened population both geographically and by host origin, was shown to have a length variation
(insertion) within the ITS region amplified by PCR. The results indicate that subgroups of P. boroniae in Western Australia may be present, with further evidence required to define the level of separation in the population.
Additional keywordsRust fungi–species-specific primer–obligate biotroph
Mint oil production from peppermint (Mentha × piperita) is a new industry in the river valleys of north-east Victoria, Australia. In this study, the disease cycles on M, × piperita, M. × gracilis (Scotch spearmint) and M. spicata (spearmint) growing in the Ovens Valley, north-east Victoria, were monitored for four years. The complete life cycle was
observed annually on M. × gracilis and M. spicata, but only urediniospores and teliospores were observed on M. × piperita. Viable urediniospores were always present on M. × piperita, confirming that urediniospores carry the disease over winter on peppermint grown in north-east Victoria. On the two spearmint
species, viable urediniospores were observed only on M. × gracilis during the 1997 winter. Reports on the disease cycle of P menthae in the mint-growing regions of the United States of America, the United Kingdom and New Zealand have shown that P. menthae is macrocyclic, with teliospores as the mechanism for overwintering, but the present study concludes that it is microcyclic
on peppermint growing under local conditions.
