Identification of Monilia species in Tibet and characterization of M. yunnanensis in China

Plant Disease ◽  
2021 ◽  
Author(s):  
Liangfen Yin ◽  
Song Huang ◽  
Qin Tan ◽  
Yang Zhou ◽  
Guoqing Li ◽  
...  

Samples of peach and plum fruits with brown rot symptoms were collected from Tibet in 2019 and 2020, and the causal agent was identified as Monilia yunnanensis, which represents the first characterization of Monilia spp. on peach and plum in Tibet. Morphological investigation showed that some conidia from naturally diseased fruits were larger than those observed in previously isolated M. yunnanensis. Some conidia of M. yunnanensis isolates from Tibet produced more than two, even up to six germ tubes from different parts of each conidium, instead of one or two germ tubes developing from the pointy sides of each conidium. The alignment of ribosomal internal transcribed spacer region (ITS) sequences revealed that some isolates from Tibet displayed a mutation at the 374th position from adenine (A) to cytosine (C). Although above-mentioned differences were observed between isolates from Tibet and other regions, phylogenetic analysis indicated that all of the M. yunnanensis isolates from different stone fruits and different regions in China were clustered together without obvious genetic differentiation. These results revealed that hosts and geographical environments did not play a major role in the evolution of M. yunnanensis.

Plant Disease ◽  
2010 ◽  
Vol 94 (11) ◽  
pp. 1314-1322 ◽  
Author(s):  
C. Bacharis ◽  
A. Gouziotis ◽  
P. Kalogeropoulou ◽  
O. Koutita ◽  
K. Tzavella-Klonari ◽  
...  

Isolates of Rhizoctonia spp. were obtained during the spring of 2007 from diseased cotton and tobacco seedlings showing damping-off symptoms. The sampled fields were located in the main cotton- and tobacco-cultivating regions of central and northern Greece. Among the 79 isolates obtained from cotton plants, 17 were binucleate and 62 were multinucleate whereas, among the 89 isolates obtained from tobacco plants, 87 were multinucleate and only 2 were binucleate. Characterization of anastomosis groups (AGs) was performed with hyphal anastomosis reactions using tester isolates of known AG groups. Anastomosis reactions in cotton mutlinucleate isolates showed that 54 of them belonged in Rhizoctonia solani AG-4, 6 in AG-7, 1 in AG-2, and 1 in AG-3. In the 87 tobacco multinucleate isolates, anastomosis reactions showed that 70 of them belonged in R. solani AG-2, 16 in AG-4, and 1 in AG-5. In addition, molecular characterization was carried out using the specific ribosomal DNA internal transcribed spacer region, in a randomly selected number of isolates. In cotton, the most prevalent AG was AG-4, with 18 isolates to the subgroup HG-I, 1 isolate to the subgroup HG-II, and 7 isolates to the subgroup HG-III, followed by AG-7 (7 isolates), AG-2-1 (1 isolate), and AG-3 (1 isolate). In tobacco, the most prevalent group was AG-2-1 (70 isolates), followed by AG-4 (6 isolates to the subgroup HG-I and 5 isolates to the subgroup HG-III) and a single isolate belonging to AG-5. Phylogenetic analysis showed that the isolates were distinctly separated based on their AG types. Pathogenicity and aggressiveness of the isolates to several hosts was determined. AG-4 isolates from either cotton or tobacco were the most aggressive on the hosts tested, while AG-2-1 isolates were of moderate aggressiveness and were not pathogenic on barley.


2021 ◽  
Author(s):  
Diego Cunha Zied ◽  
Wagner G. Vieira Junior ◽  
Douglas M. M. Soares ◽  
Cassius V. Stevani ◽  
Eustáquio S. Dias ◽  
...  

Abstract The mushroom Agaricus subrufescens has been synonymous with Agaricus blazei and Agaricus brasiliensis during the last decades and there has been much discussion with regards to the origin, distribution, and nomenclature of this mushroom. Therefore, we conducted a genetic and morphological characterization of the mycelium and mushroom of four commercial strains currently cultivated in Brazil (ABL CS7, ABL 18/01, ABL 98/11, and ABL 16/01) together with an assessment of their agronomic behavior and compared these results with those of other strains used during the last 15 years. All the A. subrufescens strains characterized here are phylogenetically related to the Americas/Europe specimens, bearing an internal transcribed spacer region of type A (ABL 16/01) or both types A and B (ABL 18/01, ABL 98/11, and ABL CS7). We did not find any correlation between the morphological characteristics of the mycelial colonies and the agronomic behavior of the strains. Strains ABL 98/11 and ABL 16/01 produced the best yields and morphological characteristics for the mushrooms, indicating their high weight, which enhances the commercialization of the mushroom and justifies their longstanding commercial use over the last 15 years.


Plant Disease ◽  
1998 ◽  
Vol 82 (2) ◽  
pp. 195-202 ◽  
Author(s):  
Chuanxue Hong ◽  
Themis J. Michailides

Naturally growing apothecia of Monilinia fructicola were collected from two commercial plum orchards near Reedley and Sanger, both in Fresno County, California. Ascospore discharges from 90 (1996) and 86 (1997) apothecia were monitored individually using spore traps at four constant temperatures. The period of discharge decreased as temperature increased from 10 to 25°C. However, daily discharge increased as temperature increased from 10 to 15°C and remained high at 20 and 25°C. The greatest discharge occurred with apothecia at 15°C, followed by those incubated at 20, 10, and 25°C. The germination of ascospores of M. fructicola and the length of germ tubes increased as temperature increased from 7 to 15°C; however, increasing temperatures above 15°C did not increase either ascospore germination or length of germ tubes. This information may help in the development of warning systems and management strategies for brown rot blossom blight of stone fruits.


2007 ◽  
Vol 85 (1) ◽  
pp. 104-110 ◽  
Author(s):  
Maria Romeralo ◽  
Omar Fiz-Palacios ◽  
Carlos Lado ◽  
James C. Cavender

Three dictyostelid isolates were found in Spain and Argentina that are morphologically different from known species. These isolates have some features similar to Dictyostelium sphaerocephalum (Oudem.) Sacc., Marchal & É.J. Marchal, but differ in size and sorocarp branching pattern. We sequenced the nuclear ribosomal internal transcribed spacer region to explore phylogenetic relationships among this group of species, including the three new isolates and their closest relatives. In all phylogenetic analyses performed, sequences of all three isolates group together with sequences from “typical” D. sphaerocephalum samples. This result supports previous observations of the morphological plasticity in dictyostelids, especially D. sphaerocephalum, leading us to broaden the classical concept of this species.


2020 ◽  
Vol 55 (4) ◽  
pp. 520-546
Author(s):  
Chengcai Si ◽  
Keke Chen ◽  
Ruisong Tao ◽  
Chengyong Su ◽  
Junye Ma ◽  
...  

Abstract Parnassius (Lepidoptera: Papilionidae) is a genus of attractive butterflies mainly distributed in the mountainous areas of Central Asia, the Himalayas, and western China. In this study, we used the internal transcribed spacer (ITS1 and ITS2) sequence data as DNA barcodes to characterize the genetic differentiation and conduct the phylogenetic analysis and divergence time estimation of the 17 Parnassius species collected in China. Species identification and genetic differentiation analysis suggest that the ITS barcode is an effective marker for Parnassius species identification; additionally, a relatively high level of genetic diversity and low level of gene flow were detected in the five Parnassius species with diverse geographic populations. Phylogenetic analysis indicates that the 17 species studied were clustered in six clades (subgenera), with subgenus Parnassius at the basal position in the phylogenetic trees. Bayesian divergence time estimation shows that the genus originated about 18 million years ago during the early Miocene, correlated with orogenic events in the distribution region, probably southwestern China about 20–10 million years ago. Our estimated phylochronology also suggests that the Parnassius interspecific and intraspecific divergences were probably related with the rapid rising of the Qinghai-Tibet Plateau, the Tibet Movement, the Kunlun-Yellow River Tectonic Movement, and global cooling associated with intensified glaciation in the region during the Quaternary Period.


Plant Disease ◽  
2015 ◽  
Vol 99 (12) ◽  
pp. 1775-1783 ◽  
Author(s):  
Liang-Fen Yin ◽  
Shu-Ning Chen ◽  
Guo-Kang Chen ◽  
Guido Schnabel ◽  
Sheng-Fang Du ◽  
...  

In total, 112 Monilinia spp. single-spore isolates were collected from plum fruit (Prunus salicina) symptomatic for brown rot disease from Yunnan, Hubei, and Zhejiang provinces and Chongqing municipality, China between 2012 and 2014. Three distinct colony morphologies (phenotypes) were observed on potato dextrose agar and two isolates per phenotype were selected for further analysis. Colony color, colony shape, conidia size, number of germ tubes per conidia, and pathogenicity on plum were investigated. The ribosomal internal transcribed spacer regions 1 and 2 as well as a polymerase chain reaction-based method that amplified fragments of the glyceraldehyde-3-phosphate dehydrogenase (G3PDH) and β-tubulin (TUB2) genes were used to identify the isolates to the species level. The three phenotypes were identified to be three different species: Monilinia fructicola, Monilia mumecola, and Monilia yunnanensis. Phylogenetic analysis based on G3PDH and TUB2 nucleotide sequences revealed that isolates within species clustered together regardless of host or geographical origin, suggesting that these factors did not play an important role for the evolutionary separation of the described species.


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