Search

The present investigation was aimed to study the sequence, phylogenetic and haplotype analyses of Toxocara cati based on the ITS region, along with the genetic diversity, demographic history and population-genetic structure. The maximum likelihood tree based on Kimura 2-parameter model was constructed using the complete ITS region of all the nucleotide sequences (n = 57) of Toxocara spp. and other related ascarid worms available in the GenBank™. It placed all the sequences of T. cati into four major clades designated as T. cati genotypes 1-4 (TcG1-G4). A total of 66 signature nucleotides were identified in the ITS region between genotypes. The median-joining haplotype network displayed a total of 24 haplotypes, with China exhibiting the highest number of haplotypes (h = 20) followed by India (h = 4), and Japan and Russia (h = 1). It indicated a clear distinction between all the four genotypes. The pairwise F ST values between all the genotypes indicated huge genetic differentiation (> 0.25) between different T. cati genotypes. Moreover, the gene flow (Nm) between T. cati genotypes was very low. Results of AMOVA revealed higher genetic variation between genotypes (92.82%) as compared to the variation within genotypes (7.18%). The neutrality indices and mismatch distributions for the G1-G4 genotypes, Indian isolates and the overall dataset of T. cati indicated either a constant population size or a slight population increase. The geographical distribution of all the genotypes of T. cati is also reported. This is the first report of genotyping of T. cati on the basis of the ITS region., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)

Pythium stipitatum is a slow-growing oomycete and has been isolated from soil samples and plant materials from France, Tunisia, Turkey and India. Its morphological characteristics are reminiscent of those of Pythium ramificatum, discovered in Algeria by the corresponding author. Unfortunately, the Algerian isolate was not deposited in any culture collection and ultimately got lost. Those were the days when molecular description of fungi was not a fashion; hence, no molecular characteristics of the Algerian isolates were deposited to the GenBank. Moreover, its coralloid antheridial branches made it an easy prey to be considered as synonymous to Pythium minus. Because there are no living strains of P. ramificatum, and no sequence at the GenBank, it is being treated as ‘ nomen invalidum’ here. However, we have now isolated the same type of oomycete from four different countries and we have sufficient evidence, both molecular and morphological, to describe it as a new species, quite different from P. minus. In this article, we are giving the morphological and molecular evidence to separate it as a distinct species, P. stipitatum, belonging to the ‘Clade E’ of the genus Pythium. Taxonomic description of this oomycete, its comparison with related species, and the sequence of the internal transcribed spacer region of its rRNA gene, are discussed here. [ABSTRACT FROM AUTHOR]

Pythium kashmirense sp. nov. was isolated from soil samples taken on the Himalayas at the height of 5300 feet in the Shivalik Hill Range of the northern Indian state of Jammu and Kashmir. The oomycete has filamentous-inflated type sporangia and its antheridial filaments form loose loops around the female gametangia, and coil around the oogonial stalks. The new species is closely related to Pythium plurisporium, Pythium periilum, Pythium inflatum, and Pythium folliculosum. All of these oomycetes have filamentous-inflated type sporangia. However, P. kashmirense has its own distinguishing characteristics which can easily differentiate it among these related species. The sequences of the internal transcribed spacer (ITS) region of its rRNA and its morphological characters are unique for the genus Pythium. Taxonomic description of this new species, its comparison with related oomycetes and the sequence of the ITS region of its rRNA, are discussed here. [ABSTRACT FROM AUTHOR]

Three strains (AP19, AP19-4 and AP19-6) of a novel yeast species were isolated from soil from the Singareni coal mines, Andhra Pradesh, India. They were morphologically, physiologically and phylogenetically identical and produced one to four spherical ascospores per ascus. Phylogenetic analysis using the D1/D2 variable domain of the large-subunit rRNA gene indicated that the closest relative of these strains is Debaryomyces etchellsii (2.6% divergence). Other species related to these strains are D. mycophilus (5.1% divergence) and species of the D. hansenii cluster (4.9–5.6% divergence). The novel species differs by 20 and 15 physiological tests from D. etchellsii and D. mycophilus, respectively. Phylogenetic analysis of the internal transcribed spacer (ITS) region also indicated that strains of the new species are related to D. etchellsii (7.7% divergence), followed by species of the D. hansenii cluster (9–10% divergence). In the small-subunit rRNA gene sequences, they differed from D. etchellsii by seven substitutions and one insertion or deletion of a base in a sequence (indel) and from D. mycophilus by 17 substitutions and 1 indel. The physiological, biochemical and molecular data suggest that these strains belong to a novel species, for which we propose the name Debaryomyces singareniensis sp. nov. The type strain of AP19T (=MTCC 7061T=CBS 10405T). The Mycobank number of the new species is MB510046. [ABSTRACT FROM AUTHOR]

Phenotypic and genetic diversity of 59 Macrophomina phaseolina isolates collected from various host species growing in or near cluster bean ( Cyamopsis tetragonoloba) fields in four states of north and north-west India were characterized using RAPD and PCR–RFLPs of the ITS region. These isolates, and 11 from various hosts from culture collections, were classified into three mycelial phenotypes: dense, feathery and restricted, based on variable growth patterns on nutrient agar containing 120 mm chlorate. Pathogenicity of isolates was evaluated by measuring the length of stem lesions 21 days post-inoculation on the susceptible cluster bean genotype FS 277. Isolates showed considerable variation in aggressiveness, with the isolates from cluster bean with dense chlorate phenotype producing relatively higher lesion lengths on cluster bean plants. The results of the RAPD assay clearly distinguished the isolates on the basis of chlorate phenotype and host origin. Isolates from a single host were generally similar to each other, but differed distinctly from those from other hosts. Chlorate-sensitive isolates were distinct from chlorate-resistant isolates within a given host. A high degree of polymorphism in restriction patterns of the ITS region, including part of 25S rDNA, has been reported for the first time in the charcoal rot fungus. [ABSTRACT FROM AUTHOR]

Pythium campanulatum sp. nov. was isolated from some soil samples taken in the rhizosphere of maize (Zea mays) in north-eastern India. This species is characterized by the absence of zoospores and sporangia, antheridial branches wrapping around the oogonia leaving one to two campanulate antheridial cells after fertilization, and aplerotic oospores. The ITS region of its rDNA is comprised of 922 bases. This oomycete is closely related to Pythium orthogonon, Pythium nunn and Pythium toruloides. However, it has its own characteristic features and is completely devoid of zoospores. Taxonomic description of this new species and its comparison with related oomycetes, together with the sequence of the PCR-amplified internal transcribed region (spacers ITS1, ITS2, and the gene 5.8S) of its rDNA are given here. [Copyright &y& Elsevier]

• Morphological description, molecular and multivariate analyses of two new species of Euplotes - E. lynni nov. spec. and E. indica nov. spec. • Description of two Indian populations of Euplotes - E. aediculatus and E. woodruffi. • Phylogenetic analysis and systematic position of all the species using multiple marker genes, SSU rRNA gene, ITS region and COI gene. • Systematic notes on the phylogeny of genus Euplotes based on the present study have been discussed. Four species belonging to the genus Euplotes have been investigated, namely: E. lynni nov. spec., E. indica nov. spec., E. aediculatus, and E. woodruffi. All populations are from India and were investigated using morphological and molecular markers. The phylogenetic relationships were inferred from small subunit ribosomal rRNA gene (SSU rRNA), internal transcribed spacer (ITS) region, and mitochondrial cytochrome c oxidase subunit I (COI) gene. Predicted secondary structure models for two new species using the hypervariable region of the SSU rRNA gene and ITS2 region support the distinctness of both species. Morphological characters were subjected to principal component analysis (PCA) and genetic variations were studied in-depth to analyze the relatedness of the two new species with their congeners. An integrative approach combining morphological features, molecular analysis, and ecological characteristics was carried out to understand the phylogenetic position of the reported species within the different clades of the genus Euplotes. [ABSTRACT FROM AUTHOR]