School Of Basic And Applied Sciences

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Author: search.filters.author.John, Aijaz Ahmad

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    Strong endemism of bloom-forming tubular Ulva in Indian west coast, with description of Ulva paschima Sp Nov (Ulvales, Chlorophyta)
    (PLOS One, 2014) Bast, Felix; John, Aijaz Ahmad; Bhushan, Satej
    Ulva intestinalis and Ulva compressa are two bloom-forming morphologically-cryptic species of green seaweeds widely accepted as cosmopolitan in distribution. Previous studies have shown that these are two distinct species that exhibit great morphological plasticity with changing seawater salinity. Here we present a phylogeographic assessment of tubular Ulva that we considered belonging to this complex collected from various marine and estuarine green-tide occurrences in a ca. 600 km stretch of the Indian west coast. Maximum Likelihood and Bayesian Inference phylogenetic reconstructions using ITS nrDNA revealed strong endemism of Indian tubular Ulva, with none of the Indian isolates forming part of the already described phylogenetic clades of either U. compressa or U. intestinalis. Due to the straightforward conclusion that Indian isolates form a robust and distinct phylogenetic clade, a description of a new bloom-forming species, Ulva paschima Bast, is formally proposed. Our phylogenetic reconstructions using Neighbor-Joining method revealed evolutionary affinity of this new species with Ulva flexuosa. This is the first molecular assessment of Ulva from the Indian Subcontinent.
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    DNA Barcoding of a new record of epi-endophytic green algaeUlvellaleptochaete(Ulvellaceae, Chlorophyta) in India
    (Indian Academy of Science, 2014) Bast, Felix; Bhushan, Satej; John, Aijaz Ahmad
    Epi-endophytic green algae comprise one of the most diverse and phylogenetically primitive groups of green algae and are considered to be ubiquitous in the world's oceans; however, no reports of these algae exist from India. Here we report the serendipitous discovery of Ulvella growing on intertidal green algae Cladophora glomerata and benthic red algae Laurencia obtusa collected from India. DNA barcodes at nuclear ribosomal DNA Internal Transcriber Spacer (nrDNA ITS) 1 and 2 regions for Indian isolates from the west and east coasts have been generated for the first time. Based on morphology and DNA barcoding, isolates were identified as Ulvella leptochaete. Phylogenetic reconstruction of concatenated dataset using Maximum Likelihood method differentiated Indian isolates from other accessions of this alga available in Genbank, albeit with low bootstrap support. Monophyly of Ulvella leptochaete was obvious in both of our phylogenetic analyses. With this first report of epi-endophytic algae from Indian territorial waters, the dire need to catalogue its cryptic diversity is highlighted and avenues of future research are discussed.
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    European Species of Subaerial Green Alga Trentepohlia annulata (Trentepohliales, Ulvophyceae) Caused Blood Rain in Kerala, India
    (OMICS, 2015) Bast, Felix; Bhushan, Satej; John, Aijaz Ahmad; Achankunju, Jackson; MV Panikkar, Nadaraja; Hametner, Christina; Stocker-W�rg�tter, Elfriede
    In 2011, isolated parts in south Indian state of Kerala as well as neighboring Sri Lanka experienced sporadic spell of red colored “blood rain”, cause of which was later attributed to terrestrial subaerial microalgae of the genus Trentepohlia. Green algae of this genus is commonly found living in symbiosis as phycobionts of lichens in the freeliving form in adjoining tropical rain forests, however, specific identity of which have never been determined. It is known that lichens disperse small algal-hyphal packages, so-called soredia, for vegetative reproduction, which can explain the content of Trentepohlia-spores in the water. Given its extraordinary spore-dispersal mechanism via rain, we were specifically interested to know species-level identity of a randomly collected Trentepohlialean algae of “blood rain” region, and to investigate the possibility that this might had been introduced from elsewhere through areal route. Results of our comparative morphology and molecular phylogenetic analyses using the nuclear ribosomal DNA Internal Transcribed Spacers region concluded that this alga is Trentepohlia annulata – a species of which no previous reports exist from India. These two geographical isolates were separated by Kimura-2-Parameter pair-wise distance of 0.06-which in turn indicate a low rate of evolution at these loci that are renowned for rapid molecular evolution, suggestive of a recent introduction. Phylogeny reconstruction using Bayesian Inference and Maximum Likelihood methods resulted in well-resolved phylograms with a robust clade composed of these isolates. This finding indicates the existence of areal dispersal of algal spores on continental and global scales through “clouds over oceans”- a phenomenon earlier reported for bacteria and fungi, but for the first time in algae.
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    Cladophora goensis sp. nov. (Cladophorales, Ulvophyceae) –a bloom forming marine algae from Goa, India
    (CSIR- NISCAIR, 2015) Bast, Felix; John, Aijaz Ahmad; Bhushan, Satej
    A new species of green seaweed, Cladophora goensis sp. nov. (Cladophorales, Ulvophyceae), had been discovered from Vasco-da-Gamma, Goa, India. This species formed algal bloom of moderate intensity in the Bay of Mormugao, on the west coast of India. Observations suggest combination of a number of morphological characteristics of this alga distinct from previously described members of this genus, including parietal chloroplast surrounding central hollow and bilenticular pyrenoids. Molecular sequence data at Nuclear ribosomal DNA Internal Transcribed Spacer-1 and 2 (ITS1 and ITS2) regions along with intervening 5.8S rRNA indicated Kimura-2-Parameter (T3P) pair-wise distance of 1.77 x 10-1 between this species and the nearest phylogenetic accession of Cladophora glomerata. In phylogenetic reconstructions using Bayesian Inference and Maximum Likelihood, this species was not part of any monophyletic clades comprising any of the previously described species of this genus at the locus studied, thereby ascertaining conformity with phylogenetic species concept. With this discovery, a new phylogenetically primitive morphological synapomorphy of “pseudo dichotomous profuse branching” has been revealed for cladophoralean algae, and this is the single most important morphological characteristic of this bloom- forming seaweed.
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    Morphological and molecular assessment of native carrageenophyte Hypnea valentiae (Cystocloniaceae, Gigartinales) in Indian Subcontinent
    (Phycological Society, 2014) Bast, Felix; Bhushan, Satej; John, Aijaz Ahmad
    Hypnea valentiae is an important red alga commercially cultivated in various parts of the world for the production of carrageenan. Presented in this report is findings of morphological and molecular observations of naturally-occurring populations of this alga collected from west and east coasts of India. Both the isolates had similar external as well as microscopic morphology. Nuclear ribosomal DNA Internal Transcribed Spacer-1 (ITS1) sequences from these geographical isolates had 4.35 x 10 -1 Tamura-3-Parameter (T3P) pairwise distance between them, which indicate significant evolutionary differences accumulated over time. In comparison, T3P distance between related genera Kappaphycus and Eucheuma was 1.85 x 10 -1 . In our phylogeny reconstruction using Bayesian Inference, both the isolates formed a well- supported clade along with the only available accession of this genus at ITS1 locus, indicating affiliation of both the isolates in this genus. Interestingly, isolate from the west coast was more basal in the phylogram, which suggests phylogenetically primitive position of this population. Newly generated DNA barcodes of the geographic isolates of this native carragenophyte in this study is expected to be a key in tracing its further dispersal routes, either natural or deliberate. This is the first report on the comparative morphological and molecular assessment of Hypnea from India.
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    Strong endemism of bloom-forming tubular ulva in Indian west coast, with description of Ulva paschima sp. nov. (Ulvales, chlorophyta)
    (Public Library of Science, 2014) Bast, Felix; John, Aijaz Ahmad; Bhushan, Satej
    Ulva intestinalis and Ulva compressa are two bloom-forming morphologically-cryptic species of green seaweeds widely accepted as cosmopolitan in distribution. Previous studies have shown that these are two distinct species that exhibit great morphological plasticity with changing seawater salinity. Here we present a phylogeographic assessment of tubular Ulva that we considered belonging to this complex collected from various marine and estuarine green-tide occurrences in a ca. 600 km stretch of the Indian west coast. Maximum Likelihood and Bayesian Inference phylogenetic reconstructions using ITS nrDNA revealed strong endemism of Indian tubular Ulva, with none of the Indian isolates forming part of the already described phylogenetic clades of either U. compressa or U. intestinalis. Due to the straightforward conclusion that Indian isolates form a robust and distinct phylogenetic clade, a description of a new bloom-forming species, Ulva paschima Bast, is formally proposed. Our phylogenetic reconstructions using Neighbor-Joining method revealed evolutionary affinity of this new species with Ulva flexuosa. This is the first molecular assessment of Ulva from the Indian Subcontinent. ? 2014 Bast et al.
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    Molecular assessment of invasive Carrageenophyte Kappaphycus alvarezii from India based on ITS-1 sequences
    (Taylor and Francis Ltd., 2016) Bast, Felix; John, Aijaz Ahmad; Bhushan, Satej
    This is the first report on the molecular systematic characterization of the invasive red alga Kappaphycus alvarezii in India. Cultivated for the production of carrageenan around the Gulf of Mannar, southeast India, this exotic alga is causing havoc in coastal ecosystems by invading the habitats of a number of endemic species, especially soft corals. We have sequenced the nuclear ribosomal DNA internal transcribed spacer 1 barcode of this introduced species. In our phylogenetic analyses using Bayesian inference and maximum likelihood, this alga clustered within a well-supported clade of K.?alvarezii of mixed geographic origin. Phylogenetic analyses were congruent in their separation of K.?alvarezii and Kappaphycus striatum. Analyses also suggest that this species might have originated in the Malay Archipelago and spread elsewhere. Our results provide insights into the evolutionary and biogeographic patterns of this alga around the world. ? 2016 Dipartimento di Biologia, Universit? di Firenze.
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    New record of Sargassum zhangii (Sargassaceae, Fucales) in India based on nuclear and mitochondrial DNA barcodes
    (Taylor and Francis Ltd., 2016) Bast, Felix; Bhushan, Satej; Rani, Pooja; John, Aijaz Ahmad
    Brown algal genus Sargassum encompasses some of the most invasive seaweeds in the oceans across the world. Here we report the occurrence of Sargassum zhangii in Palk Strait, southeast India. Hundreds of natural populations of this seaweed were observed in the collection site. BLASTn similarity search using nuclear DNA internal transcribed spacer1 (ITS1) and mitochondrial DNA cytochrome oxidase 1 (COX?1) gene of this isolate indicated Sargassum zhangii as the most homologous sequence available in the repository. Pairwise distances among these isolates were very low, 2.8?נ10?3 and 1.3?נ10?2 with ITS1 and COX?1, respectively, which suggests conspecificity and a recent introduction. Phylogenetic analyses along with other members of genus Sargassum conducted using Bayesian Inference resulted in well-resolved phylograms with robust clades comprising two isolates of S.?zhangii, further confirming conspecificity. With this first report of this seaweed outside China, invasive potential of S.?zhangii is highlighted that warrants immediate global attention. As this is the first time that molecular systematics have been used to catalogue species invasion in India, its efficacy, as well as the necessity for further cataloguing of species invasions using this approach, are highlighted. ? 2016 Dipartimento di Biologia, Universit? di Firenze.