Molecular characterization of Fusarium oxysporum f. sp. ciceri causing wilt of chickpea

Thirty isolates of Fusarium oxysporum f. sp. ciceri were isolated from rhizosphere soil of chickpea from different locations in Northern India. The amount of genetic variation was evaluated by polymerase chain reaction (PCR) amplification with a set of 40 RAPD primers and 2 IGS primers. Less than 10% of the amplified fragments in each case were polymorphic. Genetic similarity between each of the isolates was calculated and results indicate that there was little genetic variability among the isolates collected from the different locations. At the 0.75 similarity index the isolates divides into three groups. Isolates Foc-A18, Foc-A19, Foc-A20 forming a similar group and far different from other isolates.Key words: Fusarium oxysporum f. sp. ciceri, Fusarium wilt of chickpea, RAPD, ITS, IGS

Measurement of Vulnerability to Climate Change in Char Areas: A Survey

Threats caused to the environment and human life by climate change have become an urgent issue. Climate change often aggravates hazards in a given area and has harmful effects on the people residing there. Affected by massive floods, land erosion, and the destruction of agricultural lands, char people live a risky life. Char dwellers are among the communities that suffer the most as a result of the effects of climate change. Few studies discuss the vulnerabilities of communities living in char areas to climate change. This paper attempts to summarize the existing research. It also discusses data-related issues in the measurement of vulnerability to climate change. It ends by raising some policy-related considerations

Measurement of Vulnerability to Climate Change in Char Areas: A Survey

Threats caused to the environment and human life by climate change have become an urgent issue. Climate change often aggravates hazards in a given area and has harmful effects on the people residing there. Affected by massive floods, land erosion, and the destruction of agricultural lands, char people live a risky life. Char dwellers are among the communities that suffer the most as a result of the effects of climate change. Few studies discuss the vulnerabilities of communities living in char areas to climate change. This paper attempts to summarize the existing research. It also discusses data-related issues in the measurement of vulnerability to climate change. It ends by raising some policy-related considerations

Alleviation of drought stress in pulse crops with acc deaminase producing rhizobacteria isolated from acidic soil of northeast india

The agricultural crops are often affected by the scarcity of fresh water. Seasonal drought is a major constraint on Northeast Indian agriculture. Almost 80% of the agricultural land in this region is acidic and facing severe drought during the winter period. Apart from classical breeding and transgenic approaches, the application of plant-growth-promoting bacteria (PGPB) is an alternative strategy for improving plant fitness under stressful conditions. The 1-aminocyclopropane-1-carboxylate (ACC) deaminase-producing PGPB offer drought stress tolerance by regulating plant ethylene levels. The aim of the present study was to evaluate the consortium effect of three ACC-deaminase producing rhizobacteria - Ochrobactrum pseudogrignonenseRJ12, Pseudomonas sp.RJ15 and Bacillus subtilisRJ46 on drought stress alleviation in Vigna mungo L. and Pisum sativum L. Consortium treatment significantly increase seed germination percentage, root length, shoot length, and dry weight of treated plants. An elevated production of reactive oxygen species scavenging enzymes and cellular osmolytes; higher leaf chlorophyll content; increase in relative water content and root recovery intension were observed after consortium treatment in comparison with the uninoculated plants under drought conditions. The consortium treatment decreased the ACC accumulation and down-regulated ACC-oxidase gene expression. This consortium could be an effective bio-formulator for crop health improvement in drought-affected acidic agricultural fields

<strong>distribution and identification of endophytic <em>streptomyces</em> species from <em>schima wallichii</em> as potential biocontrol agents against fungal plant pathogens</strong>

The prospective of endophytic microorganisms allied with medicinal plants is disproportionally large compared to those in other biomes. The use of antagonistic microorganisms to control devastating fungal pathogens is an attractive and eco-friendly substitute for chemical pesticides. Many species of actinomycetes, especially the genus Streptomyces, are well known as biocontrol agents. We investigated the culturable community composition and biological control ability of endophytic Streptomyces sp. associated with an ethanobotanical plant Schima wallichi. A total of 22 actinobacterial strains were isolated from different organs of selected medicinal plants and screened for their biocontrol ability against seven fungal phytopathogens. Seven isolates showed significant inhibition activity against most of the selected pathogens. Their identification based on 16S rRNA gene sequence analysis, strongly indicated that all strains belonged to the genus Streptomyces. An endophytic strain BPSAC70 isolated from root tissues showed highest percentage of inhibition (98.3 %) against Fusarium culmorum with significant activity against other tested fungal pathogens. Phylogenetic analysis based on 16S rRNA gene sequences revealed that all seven strains shared 100 % similarity with the genus Streptomyces. In addition, the isolates were subjected to the amplification of antimicrobial genes encoding polyketide synthase type I (PKS-I) and nonribosomal peptide synthetase (NRPS) and found to be present in most of the potent strains. Our results identified some potential endophytic Streptomyces species having antagonistic activity against multiple fungal phytopathogens that could be used as an effective biocontrol agent against pathogenic fungi

Isolation, abundance and phylogenetic affiliation of endophytic actinomycetes associated with medicinal plants and screening for their in vitro antimicrobial biosynthetic potential

Microorganisms associated with medicinal plants are of interest as the producers of important bioactive compounds. To date, the diversity of culturable endophytic actinomycetes associated with medicinal plants is in its initial phase of exploration. In this study, 42 endophytic actinomycetes were isolated from different organs of seven selected medicinal plants. The highest number of isolates (n = 22, 52.3%) of actinomycetes was isolated from roots, followed by stems (n = 9, 21.4%), leaves (n = 6, 14.2%), flowers (n = 3, 7.1%), and petioles (n = 2, 4.7%). The genus Streptomyces was the most dominant among the isolates (66.6%) in both the locations (Dampa TRF and Phawngpuii NP, Mizoram, India). From a total of 42 isolates, 22 isolates were selected for further studies based on their ability to inhibit one of the tested human bacterial or fungal pathogen. Selected isolates were identified based on 16S rRNA gene analysis and subsequently the isolates were grouped to four different genera; Streptomyces, Brevibacterium, Microbacterium, and Leifsonia. Antibiotic sensitivity assay was performed to understand the responsible antimicrobials present in the isolates showing the antimicrobial activities and revealed that the isolates were mostly resistant to penicillin G and ampicillin. Further, antimicrobial properties and antibiotic sensitivity assay in combination with the results of amplification of biosynthetic genes polyketide synthase (PKS-I) and non-ribosomal peptide synthetase (NRPS) showed that the endophytic actinomycetes associated with the selected medicinal plants have broad-spectrum antimicrobial activity. This is the first report of the isolation of Brevibacterium sp., Microbacterium sp., and Leifsonia xyli from endophytic environments of medicinal plants, Mirabilis jalapa and Clerodendrum colebrookianum. Our results emphasize that endophytic actinomycetes associated with medicinal plants are an unexplored resource for the discovery of biologically active compounds

Isolation, abundance and phylogenetic affiliation of endophytic actinomycetes associated with medicinal plants and screening for their in vitro antimicrobial biosynthetic potential

Microorganisms associated with medicinal plants are of interest as the producers of important bioactive compounds. To date, the diversity of culturable endophytic actinomycetes associated with medicinal plants is in its initial phase of exploration. In this study, 42 endophytic actinomycetes were isolated from different organs of seven selected medicinal plants. The highest number of isolates (n = 22, 52.3%) of actinomycetes was isolated from roots, followed by stems (n = 9, 21.4%), leaves (n = 6, 14.2%), flowers (n = 3, 7.1%), and petioles (n = 2, 4.7%). The genus Streptomyces was the most dominant among the isolates (66.6%) in both the locations (Dampa TRF and Phawngpuii NP, Mizoram, India). From a total of 42 isolates, 22 isolates were selected for further studies based on their ability to inhibit one of the tested human bacterial or fungal pathogen. Selected isolates were identified based on 16S rRNA gene analysis and subsequently the isolates were grouped to four different genera; Streptomyces, Brevibacterium, Microbacterium, and Leifsonia. Antibiotic sensitivity assay was performed to understand the responsible antimicrobials present in the isolates showing the antimicrobial activities and revealed that the isolates were mostly resistant to penicillin G and ampicillin. Further, antimicrobial properties and antibiotic sensitivity assay in combination with the results of amplification of biosynthetic genes polyketide synthase (PKS-I) and non-ribosomal peptide synthetase (NRPS) showed that the endophytic actinomycetes associated with the selected medicinal plants have broad-spectrum antimicrobial activity. This is the first report of the isolation of Brevibacterium sp., Microbacterium sp., and Leifsonia xyli from endophytic environments of medicinal plants, Mirabilis jalapa and Clerodendrum colebrookianum. Our results emphasize that endophytic actinomycetes associated with medicinal plants are an unexplored resource for the discovery of biologically active compounds

<strong>distribution and identification of endophytic <em>streptomyces</em> species from <em>schima wallichii</em> as potential biocontrol agents against fungal plant pathogens</strong>

The prospective of endophytic microorganisms allied with medicinal plants is disproportionally large compared to those in other biomes. The use of antagonistic microorganisms to control devastating fungal pathogens is an attractive and eco-friendly substitute for chemical pesticides. Many species of actinomycetes, especially the genus Streptomyces, are well known as biocontrol agents. We investigated the culturable community composition and biological control ability of endophytic Streptomyces sp. associated with an ethanobotanical plant Schima wallichi. A total of 22 actinobacterial strains were isolated from different organs of selected medicinal plants and screened for their biocontrol ability against seven fungal phytopathogens. Seven isolates showed significant inhibition activity against most of the selected pathogens. Their identification based on 16S rRNA gene sequence analysis, strongly indicated that all strains belonged to the genus Streptomyces. An endophytic strain BPSAC70 isolated from root tissues showed highest percentage of inhibition (98.3 %) against Fusarium culmorum with significant activity against other tested fungal pathogens. Phylogenetic analysis based on 16S rRNA gene sequences revealed that all seven strains shared 100 % similarity with the genus Streptomyces. In addition, the isolates were subjected to the amplification of antimicrobial genes encoding polyketide synthase type I (PKS-I) and nonribosomal peptide synthetase (NRPS) and found to be present in most of the potent strains. Our results identified some potential endophytic Streptomyces species having antagonistic activity against multiple fungal phytopathogens that could be used as an effective biocontrol agent against pathogenic fungi

<strong>distribution and identification of endophytic <em>streptomyces</em> species from <em>schima wallichii</em> as potential biocontrol agents against fungal plant pathogens</strong>

The prospective of endophytic microorganisms allied with medicinal plants is disproportionally large compared to those in other biomes. The use of antagonistic microorganisms to control devastating fungal pathogens is an attractive and eco-friendly substitute for chemical pesticides. Many species of actinomycetes, especially the genus Streptomyces, are well known as biocontrol agents. We investigated the culturable community composition and biological control ability of endophytic Streptomyces sp. associated with an ethanobotanical plant Schima wallichi. A total of 22 actinobacterial strains were isolated from different organs of selected medicinal plants and screened for their biocontrol ability against seven fungal phytopathogens. Seven isolates showed significant inhibition activity against most of the selected pathogens. Their identification based on 16S rRNA gene sequence analysis, strongly indicated that all strains belonged to the genus Streptomyces. An endophytic strain BPSAC70 isolated from root tissues showed highest percentage of inhibition (98.3 %) against Fusarium culmorum with significant activity against other tested fungal pathogens. Phylogenetic analysis based on 16S rRNA gene sequences revealed that all seven strains shared 100 % similarity with the genus Streptomyces. In addition, the isolates were subjected to the amplification of antimicrobial genes encoding polyketide synthase type I (PKS-I) and nonribosomal peptide synthetase (NRPS) and found to be present in most of the potent strains. Our results identified some potential endophytic Streptomyces species having antagonistic activity against multiple fungal phytopathogens that could be used as an effective biocontrol agent against pathogenic fungi