scholarly journals Identification and characterization of pathogenic Pestalotiopsis species to pecan tree in Brazil

2014 ◽  
Vol 49 (6) ◽  
pp. 440-448 ◽  
Author(s):  
Marília Lazarotto ◽  
Marciéli Pitorini Bovolini ◽  
Marlove Fátima Brião Muniz ◽  
Ricardo Harakawa ◽  
Lia Rejane Silveira Reiniger ◽  
...  
Keyword(s):  
Growth Rate ◽  
Mycelial Growth ◽  
Its Region ◽  
Morphological Characters ◽  
Morphological Characterization ◽  
Identification Methods ◽  
Initial Separation ◽  
Mycelial Growth Rate ◽  
Pathogenicity Tests

The objective of this work was to characterize and cluster isolates of Pestalotiopsis species and to identify those that are pathogenic to pecan, based on morphological and molecular characters. Pestalotiopsis spp. isolates were identified by sequencing the internal transcribed spacer (ITS) and β?tubulin regions. Identification methods were compared to indicate the key morphological characters for species characterization. Thirteen isolates were used for the pathogenicity tests. Morphological characterization was performed using the following variables: mycelial growth rate, sporulation, colony pigmentation, and conidial length and width. Ten pathogenic isolates were identified, three as -tubulin regions. Identification methods were compared to indicate the key morphological characters for species characterization. Thirteen isolates were used for the pathogenicity tests. Morphological characterization was performed using the following variables: mycelial growth rate, sporulation, colony pigmentation, and conidial length and width. Ten pathogenic isolates were identified, three as Pestalotiopsis clavispora and three as P. cocculi. The other isolates remained as an undefined species. The morphological characters were efficient for an initial separation of the isolates, which were grouped according to differences at species level, mainly colony diameter, which was identified as an important morphological describer. Beta-tubulin gene sequencing was less informative than the ITS region sequencing for species identification.

scholarly journals Phenotypic Characterization of Genetically Distinct Phytophthora cinnamomi Isolates from Avocado

2019 ◽  
Vol 109 (3) ◽  
pp. 384-394 ◽  
Author(s):  
Rodger J. Belisle ◽  
Brandon McKee ◽  
Wei Hao ◽  
Margaret Crowley ◽  
Mary Lu Arpaia ◽  
...  
Keyword(s):  
Growth Rate ◽  
Mycelial Growth ◽  
Phytophthora Cinnamomi ◽  
Phenotypic Characterization ◽  
Breeding Programs ◽  
Fungicide Sensitivity ◽  
Phytophthora Root Rot ◽  
Mycelial Growth Rate ◽  
Potassium Phosphite

Phytophthora cinnamomi, the causal agent of Phytophthora root rot (PRR), is the most destructive disease of avocado worldwide. A previous study identified two genetically distinct clades of A2 mating type avocado isolates in California; however, the phenotypic variation among them was not assessed. This study described the phenotype of a subset of isolates from these groups regarding growth rate, growth temperature, virulence, and fungicide sensitivity. Isolates corresponding to the A2 clade I group exhibited higher mycelial growth rate and sensitivity to higher temperatures than other isolates. Among the fungicides tested, potassium phosphite had the highest 50% effective concentration for mycelial growth inhibition and oxathiapiprolin had the lowest. Mycelial growth rate and potassium phosphite sensitivity phenotypes correlate with specific groups of isolates, suggesting that these traits could be a group characteristic. Moreover, isolates that are more virulent in avocado and less sensitive to potassium phosphite were identified. A detached-leaf P. cinnamomi inoculation method using Nicotiana benthamiana was developed and validated, providing an alternative method for assessing the virulence of a large number of isolates. This information will help avocado PRR management and assist breeding programs for the selection of rootstocks resistant against a more diverse pathogen population.

scholarly journals Morphology and mycelial growth rate of Pleurotus spp. strains from the Mexican mixtec region

2014 ◽  
Vol 45 (3) ◽  
pp. 861-872 ◽  
Author(s):  
P.C. Guadarrama-Mendoza ◽  
G. Valencia del Toro ◽  
R. Ramírez-Carrillo ◽  
F. Robles-Martínez ◽  
J. Yáñez-Fernández ◽  
...  
Keyword(s):  
Growth Rate ◽  
Mycelial Growth ◽  
Mycelial Growth Rate

scholarly journals MORPHOLOGICAL AND CHROMOSOMAL CHARACTERIZATION OF ORCHID Peristylus goodyeroides Lindl. FROM CURUG SETAWING, KULONPROGO

2021 ◽  
Vol 12 (2) ◽  
pp. 110
Author(s):  
Febri Yuda Kurniawan ◽  
Anindita Della Rosa Riyadi
Keyword(s):  
Leaf Shape ◽  
Ecological Factors ◽  
Morphological Characters ◽  
Morphological Characterization ◽  
Observation Data ◽  
Chromosome Configuration ◽  
Telocentric Chromosomes ◽  
Leaf Arrangement ◽  
Karyotype Formula

Peristylus goodyeroides is a terestrial orchid that scattered around Southeast Asia. Morphological characters of P. goodyeroides can vary, depending on the ecological factors and habitat. Cytological characters in the form of chromosome configurations can be used as a taxonomic tool for the process of identifying and understanding variations in taxa. The purpose of this study was to determine the morphological characters and chromosome configuration of the P. goodyeroides from Curug Setawing, Kulonprogo. The method used was morphological characterization and plant chromosome preparation by squash method with the main steps of fixation, maceration, staining and observation. Data were analyzed with the help of Image raster 3, Corel Draw X7, and Microsoft Excel 2013. P. goodyeroides from Curug Setawing has the morphological characters of root tubers, cylindrical stems, ovate leaf shape, convolutive leaf arrangement and creamy white flowers. The orchid has a number of chromosomes 2n = 10 with a karyotype formula of 2n = 2x = 8m + 2t. Metacentric chromosomes are found on chromosomes 1-8 and telocentric chromosomes 9-10. The absolute arm length of the chromosomes has a range of 2.03-3.44 μm, the relative arm length of the chromosomes is 2.21-3.32 μm, the length of the p arm is 1.13-1.58 μm and the q arm is 1.23-2.12 μm.

scholarly journals Genetic and Morphological Characterization of Colletotrichum acutatum Causing Anthracnose of Lupins

2002 ◽  
Vol 92 (9) ◽  
pp. 986-996 ◽  
Author(s):  
Pedro Talhinhas ◽  
S. Sreenivasaprasad ◽  
João Neves-Martins ◽  
Helena Oliveira
Keyword(s):  
Morphological Characters ◽  
Morphological Characterization ◽  
Colletotrichum Acutatum ◽  
Distinct Subgroup ◽  
Specific Pcr ◽  
Pathogen Diversity ◽  
Polymerase Chain ◽  
Arbitrarily Primed Pcr ◽  
Pathogen Diagnosis

Anthracnose, caused by Colletotrichum sp., is a serious problem of lupins (Lupinus spp.) worldwide. Morphological characters and molecular markers were used to characterize 43 Colletotrichum isolates from lupins, 8 isolates from other hosts, and 18 reference isolates representing related Colletotrichum spp., to assess the pathogen diversity and resolve its taxonomy. All lupin Colletotrichum isolates tested positive with C. acutatum-specific polymerase chain reaction (PCR) and did not test positive with C. gloeosporioides-specific PCR. Spore shape and colony diameter as well as insensitivity to benomyl grouped the lupin anthracnose isolates closer to C. acutatum than to C. gloeosporioides. Analysis of internal transcribed spacer (ITS) sequences of 57 Colletotrichum isolates grouped all lupin isolates with C. acutatum and distinct from C. gloeosporioides. Further, tub2 and his4 sequences revealed groups concordant with ITS, reducing the excessive dependence on the latter. Arbitrarily primed-PCR and amplified fragment length polymorphism analyses revealed intraspecific subgroups, but neither was useful to decipher species level relationships. ITS, tub2, and his4 results strongly support designating lupin anthracnose pathogen as C. acutatum or its subspecies. Most Colletotrichum isolates from lupins from worldwide locations are genetically homogeneous and form a distinct subgroup within C. acutatum. Present results also underline the potential of the C. acutatum-specific PCR for routine pathogen diagnosis.

scholarly journals Antagonism of Plant Pathogens by Calotropis procera

2021 ◽  
Vol 13 (4) ◽  
pp. 120
Author(s):  
Karla Danielle Nogueira Cardoso ◽  
Maria Josiane Martins ◽  
Thaisa Aparecida Neres de Souza ◽  
Isabelle Carolyne Cardoso ◽  
Patrícia Nirlane da Costa Souza ◽  
...  
Keyword(s):  
Growth Rate ◽  
Aqueous Extract ◽  
Mycelial Growth ◽  
Plant Pathogens ◽  
Calotropis Procera ◽  
Mycelial Growth Rate ◽  
Vitro Effect ◽  
Fungal Colony

Phomopsis sojae and Sclerotinia sclerotiorum are responsible for stem and pod dryness and white mold in soybean. These pathologies directly affect the quality of seeds/grains and compromise the entire plant. The use of extracts from different plants has been the subject of research for the control of several phytopathogens. Calotropis procera is among botanical species that synthesize efficient compounds for biocontrol. In this context, the aim of this study was to evaluate the in vitro effect of C. procera aqueous extract on P. sojae and S. sclerotiorum. The experiment was carried out in completely randomized blocks in a 2 × 5 factorial scheme (two fungi and five extract concentrations 0%, 5%, 10%, 15% and 20%) with 4 replicates. C. procera aqueous extract concentrations were added to Petri dishes containing PDA. After 48 hours, the mycelial growth rate was evaluated. After seven days of incubation, the fungal colony area, sporulation, and germination of P. sojae and S. sclerotiorum were evaluated. There was significant interaction between fungi × extract concentrations (p < 0.05) for all variables analyzed. The mycelial growth rate of P. sojae was lower than that of S. sclerotiorum. The diameter of the P. sojae fungal colony was smaller than that of S. sclerotiorum when concentrations of 5%, 10% and 15% were used. As the extract concentration increased, fungi sporulation and germination reduced.

scholarly journals Molecular Characterization, Pathogenicity and Biological Characterization of Colletotrichum Species Associated with Anthracnose of Camellia yuhsienensis Hu in China

Forests ◽  
2021 ◽  
Vol 12 (12) ◽  
pp. 1712
Author(s):  
Xinggang Chen ◽  
Lingyu Jiang ◽  
Anhua Bao ◽  
Changlin Liu ◽  
Junang Liu ◽  
...  
Keyword(s):  
Mycelial Growth ◽  
Morphological Characteristics ◽  
Biological Characteristics ◽  
Camellia Oleifera ◽  
Biological Characterization ◽  
Pathogenicity Tests ◽  
Colletotrichum Spp ◽  
And Control ◽  
First Time

Camellia yuhsienensis Hu, a species of tea oil tree with resistance to anthracnose, is widely used to breed disease-resistant Camellia varieties. In 2019, anthracnose symptoms were observed on Ca. yuhsienensis for the first time. However, the species and biological characteristics of Colletotrichum spp. isolated from Ca. yuhsienensis (YX-Colletotrichum spp.) have not been elucidated. In this study, five isolates (YX2-5-2, 2YX-3-1, 2YX-5-1, 2YX-8-1-1 and 2YX-8-1-2), which were consistent with the morphological characteristics of Colletotrichum spp., were obtained from Ca. yuhsienensis. A phylogenetic analysis demonstrated that YX2-5-2, 2YX-3-1 and 2YX-8-1-2 belonged to first clade along with Colletotrichum fructicola. 2YX-8-1-1 belonged to the second clade along with Colletotrichum siamense. 2YX-5-1 belonged to the third clade with Colletotrichum camelliae. Pathogenicity tests revealed that the pathogenicity of YX-Colletotrichum spp. was stronger than that of Colletotrichum spp. isolated from Camellia oleifera (GD-Colletotrichum spp.). Biological characteristics illustrated that the mycelial growth of YX-Co. camelliae (2YX-5-1) was slower than that of GD-Co. camelliae when the temperature exceeded 20 °C. In addition, in the presence of ions, the mycelial growth of YX-Co. fructicola (YX2-5-2) and YX-Co. siamense (2YX-8-1-1) was also slower than that of GD-Co. fructicola and GD-Co. siamense. Furthermore, the ability of YX-Colletotrichum spp. to utilize lactose and mannitol was weaker than that of GD-Colletotrichum spp., while the ability to utilize NH4+ was generally stronger than that of GD-Colletotrichum spp. This is the first report of anthracnose of Ca. yuhsienensis induced by Co. fructicola, Co. siamense and Co. camelliae in China. These results will provide theoretical guidance for the study of the pathogenesis and control of anthracnose on Ca. yuhsienensis.

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