Endophytic bacteria associated with banana cultivars and their inoculation effect on plant growth

The occurrence and role of endophytic bacterial communities in banana under different field-grown conditions have not yet been explored. Hence, a survey was conducted in five different banana cultivars – Rasthali, Hill banana, Co1, Nattu Poovan and Red banana – for the assessment of bacterial endophytes grown in Tamil Nadu, Southern India. From 352 endophytes isolated, 17 were selected based on distinct morpho-physiological characters. The 17 selected isolates were grouped into eight different genera, which belong to the phyla Actinobacteria, Firmicutes and Proteobacteria, with remarkable differences in the bacterial compositions among the banana cultivars. Higher bacterial diversity was observed in Rasthali and Red banana when compared to Co1 and Nattu Poovan. Isolates exhibited at least one functional plant growth-promoting trait when tested for siderophore production and indole-3-acetic acid (IAA) synthesis. Representative isolates from eight different genera were further analyzed for plant–microbe interactions. A seedling inoculation experiment on tomato showed a significant effect on seed germination, seedling growth, vigor index, and biomass production compared to the uninoculated control. However, a comprehensive approach is needed to evaluate the full potential of bacterial endophytes to improve quality and yield in banana under field conditions.     

Nano zinc supplementation in goat (Capra hircus) ration improves immunity,serum zinc profile and IGF-1 hormones without affecting thyroid hormones

The trial was aimed at evaluating probable superiority, if any of nano zinc (NZn) over inorganic zinc (Zn) on immunity, serum minerals and T₃, T₄, and IGF-1 hormone profiles in goats. NZn was synthesized by using 0.45 M aqueous solution of Zn nitrate and 0.9 M aqueous solution of sodium hydroxide (average particle size 74 nm). Twenty-four male goats were grouped into four groups as per their body weight and were supplemented with either a basal diet with concentrate and straw at 50:50 ratio (Negative control, NC) alone or supplemented with 50 mg/kg Zn (Control) from inorganic Zn source, that is ZnO (IZn-50), 50 mg/kg Zn from NZn (NZn-50) or 25 mg/kg Zn from NZn (NZn-25). No change was observed in thyroid hormone status on zero and 90th day of experimental feeding, but NZn supplementation improved (p < 0.05) IGF-1 level on 90th day serum samples. Zn supplementation improved the humoral immunity in all the groups irrespective of the source. Similarly, cell-mediated immunity (CMI) measured by skinfold thickness after injecting Con-A, was also improved in Zn supplemented groups than control at 6, 12 and 48 h of incubation. NZn-50 animals showed highest HI (haemagglutination inhibition) titre as well as skin thickness. The (cluster of differentiation in %) was more (p < 0.05) in Zn supplemented groups. NZn-50 showed higher (p < 0.05) count than NC and similar (p > 0.05) to IZn-50 and NZn-25 groups without affecting (p > 0.05) the ratio of , among the treatment groups. Thus, NZn supplementation at 25 mg/kg had similar immunity and serum T₃, T₄ and IGF-1 profiles compared with IZn at 50 mg/kg dose.     

Inheritance of compact dwarf plant type in pigeonpea (Cajanus cajan)

A compact dwarf plant type TDT2004-1 isolated from the progeny of a cross involving Cajanus cajan (cv. 'C-11') and C. cajanifolia was investigated for its inheritance. Pigeonpea genotype TDT2004-1 is semi-determinate in growth habit; short (approximately 37 cm) with reduced internodal length (1.2 cm), a compact canopy and a high harvest index (40%), while genotype TT44-4 is indeterminate in growth habit; tall (132 cm) with normal internodal length (2.3 cm), an open canopy and a low harvest index (28.9%). The inheritance study involving cross TT44-4 × TDT2004-1 showed that the compact dwarf plant type was governed by a single recessive gene. TDT2004-1 could be utilized for improving the harvest index and also for restructuring the plant canopy in pigeonpea.     

Establishment,purification, maintenance and serological diagnosis of <Emphasis Type="Italic">Sunflower necrosis virus</Emphasis> in callus

The calli induction from different Sunflower necrosis virus (SNV)-infected explants of sunflower was initiated on Murashige & Skoog medium amended with benzyladenine at 1 mg l ^-1 and indole acetic acid at 0.5 mg l ^-1. The virus was purified from the induced calli by sucrose density gradient centrifugation and the viral particles were confirmed by transmission electron microscopy. The SNV infection in uninfected calli was established by a soak prick method and the viral development was confirmed by a plant infectivity test. Serological analyses such as Ouchterlony double immnuodiffusion test, enzyme-linked immunosorbent assay and Western blot using anti-SNV antibodies yielded positive reactions with the purified SNV. These investigations have demonstrated that the SNV could be cultured in calli and maintained in vitro in pure form for a long period of time.     

Note: Effects of plant oils and adhesive stickers on the mycelia growth and conidiation ofVerticillium lecanii, a potential entomopathogen

Oils enhance the efficacy of entomopathogens used as augmentative biological control agents. The effect of cheap and commonly available various plant oils,viz., sunflower oil, neem oil, pongamia oil, castor oil, gingili oil, coconut oil, groundnut oil, and the adhesive stickers laboline and Triton-X100, onVerticillium lecanii, an entomopathogen recommended for the control of major sucking pests of horticultural importance, was studied. The first four oils screened, significantly enhanced mycelia growth and conidiation. Gingili oil, coconut oil, groundnut oil and Triton-X100 were found to be poor carriers ofV. lecanii in relation to mycelia growth and conidiation. http://www.phytoparasitica.org posting July 14, 2005.     

Teleost liver hexokinase- and glucokinase-like enzymes: partial cDNA cloning and phylogenetic studies in rainbow trout (Oncorhynchus mykiss), common carp (Cyprinus carpio) and gilthead seabream (Sparus aurata)+

The efficiency of enzymatic conversion of glucose into glucose-6-phosphate in fish fed carbohydrates is still a matter of debate. This study reports the first ever identification of hexokinase-family members at a molecular level in fish. The deduced amino acid sequences of six cDNA clones allowed their assignement either to hexokinase IV (glucokinase) for rainbow trout (Oncorhynchus mykiss), common carp (Cyprinus carpio) and gilthead seabream (Sparus aurata) or to hexokinase I/II for the common carp (two clones) and the gilthead seabream, based on their similarities to known members of the HK family. The evolutionary relationships among these sequences were investigated by phylogenetic analysis. These hexokinase sequences constitute potential molecular tools for analysis of interspecific differences in dietary carbohydrate utilization in fish.     

Eco friendly natural dyes from <Emphasis Type="Italic">Syzygium cumini (L)</Emphasis> (Jambolan) fruit seed endosperm and to preparation of antimicrobial fabric and their washing properties

The present study has been focused on the extraction of natural dyes from Syzygium cumini (L.) Jambolan fruit dry seed endosperm and investigation of their phytochemicals and pharmacological characteristics. Dyes were prepared using aqueous, acidic, alcoholic and alkaline extraction techniques. UV spectral studies of the dyes showed a variation in absorption maxima and their color varied with respect to the pH and the solvent used during extraction. The dye was prepared from Jambolan fruit dry seed endosperm showed good antibacterial activity. The aqueous extraction of Jambolan fruit dry seed endosperm was able to inhibit the growth of many bacterial strains viz S. lutea, E.coli, P. aeruginosa, Pseudomonas fluorescens and S. aureus etc. The antimicrobial property of the dyes was used in developing antimicrobial fabric.     

Topological transitions in metamaterials

Light-matter interactions can be controlled by manipulating the photonic environment. We uncovered an optical topological transition in strongly anisotropic metamaterials that results in a dramatic increase in the photon density of states-an effect that can be used to engineer this interaction. We describe a transition in the topology of the iso-frequency surface from a closed ellipsoid to an open hyperboloid by use of artificially nanostructured metamaterials. We show that this topological transition manifests itself in increased rates of spontaneous emission of emitters positioned near the metamaterial. Altering the topology of the iso-frequency surface by using metamaterials provides a fundamentally new route to manipulating light-matter interactions.     

Genetic diversity and pathogenicity of <Emphasis Type="Italic">Fusarium oxysporum</Emphasis> isolated from wilted rocket plants in Italy

Thirty-six isolates of Fusarium oxysporum originated from Eruca vesicaria and Diplotaxis tenuifolia together with eight reference strains belonging to the formae speciales raphani, matthioli and conglutinans, typical on the Brassicaceae family, were tested for pathogenicity on two species of rocket plants (E. vesicaria L., syn. E. sativa, cv. ‘Rucola coltivata’; and D. tenuifolia cv. ‘Winter’) cultivated in the glasshouse. The results showed that different isolates were slightly, moderately or highly virulent. The strains were examined for differences in the nucleotide sequence of the ribosomal DNA (rDNA) intergenic spacer (IGS) region, about 2.5 kb long. The phylogenetic (neighbor-joining) analysis performed on the isolates enabled identification of four different groups, named I, II, III and IV. Thirty-one isolates out of 36 clustered in group I and were genetically similar to F. oxysporum f.sp. raphani. By considering the pathogenicity of the strains included in Group I, a partial host specialization could be observed: the average disease index of the isolates from D. tenuifolia was higher on wild rocket, whereas the average disease index of the isolates from E. vesicaria was higher on cultivated rocket. Moreover, isolates from cultivated rocket showed, on average, a higher degree of aggressiveness than the isolates from wild rocket. Concerning Group I, the sequence analysis confirmed the homogeneity of the population, with only five parsimony-informative SNPs and five haplotypes. Twenty-six out of 31 isolates belonged to haplotype 1. Groups II and III were genetically similar to strains of F. oxysporum f.sp. matthioli. Three other strains, not pathogenic or with a medium level of virulence, clustered together in Group 4, but their sequence was distant from that of other formae speciales. The pathogenicity and IGS analysis confirmed the presence of virulence variation and genetic diversity among the F. oxysporum isolates studied. To our knowledge, this is the first report of differentiation of formae speciales of F. oxysporum on rocket plants by IGS analysis.