Biochemical and histochemical traits: a promising way to screen resistance against spot blotch (Bipolaris sorokiniana) of wheat

Spot blotch caused by Bipolaris sorokiniana is a serious disease of wheat in warmer and humid regions of the world. Three blighting components, area under disease progress curve (AUDPC), disease severity (DS) and lesion size along with four biochemical and histochemical factors viz., total phenol content (TPC), chlorophyll content (CHC), phenylalanine ammonia-lyase (PAL) activity and lignin deposition were studied in a recombinant inbred lines (RILs) population involving parents “Sonalika” (susceptible) and “Yangmai 6” (resistant). The objective was to identify one or more robust and reliable tools of resistance, physical, biochemical or histochemical, to facilitate selection against spot blotch. The DS, AUDPC and lesion size were higher in the susceptible parent and RILs compared to the resistant. The mean TPC (246 mg Gallic acid g^?1 fresh weight) of the most resistant RIL was significantly higher than the most susceptible (181.5 mg Gallic acid g^?1 fresh weight) at 48 h after inoculation (hai). The mean SPAD value for CHC varied between 48.8 in the most resistant RILs to 8.8 in the most susceptible, while the mean PAL varied between 928.4 and 96.0 μmoles Cinnamic acid mg^-1 fresh weight at 48 hai in resistant and susceptible RILs, respectively. Likewise, lignin deposition was significantly higher in resistant RILs compared to the susceptible. The biochemical and histochemical parameters were significantly correlated with resistance and appeared robust for facilitating screening of breeding material and for increased precision in phenotyping against spot blotch.     

SPI/PEO blended electrospun martrix for wound healing

Conventional textile based wound dressing materials are cost effective and highly absorbent, but when used alone fails to provide optimal wound healing conditions like homeostasis, non-adherence, maintenance of a moist wound bed, etc. Electrospun polymer web meets the requirements outlined for wound healing, by their microfibrous structures provide suitable environment for wound healing apart from the function of polymers. In this study, blends of soy protein isolate (SPI) and poly(ethylene oxide) (PEO) nano fiber web was prepared by electro spinning process. The developed blended nano fiber web was subjected to SEM, FTIR to evaluate fiber size and functional properties respectively. The Moisture vapour transmission rate (MVTR) result shows the blended electrospun web gives suitable mosit environment over wound bed such as the MVTR is 2994 g/m²/day. The blended electrospun web gives positive result on antimicrobial activity. The effect of SPI/PEO blended electrospun web on wound healing was experimented with female wistar rats and the blended electrospun web shows excellent result on wound healing by the growth of new epithelium without any significant adverse reaction. Forming of SPI/PEO electrospun fiber was fulfilled many critical elements desirable in a wound material.     

Soil fertility and establishment potential of inoculated cyanobacteria in rice crop grown under non-flooded conditions

An investigation was undertaken using a combination of microbiological and DNA-based approaches to evaluate combinations of two/three/four cyanobacterial strains (BF1 Anabaena torulosa; BF2, Nostoc carneum; BF3, Nostoc piscinale; BF4, Anabaena doliolum), using a novel vermicompost-based carrier, for their promise as inoculants in rice crop. The crop was maintained under 60% WHC through intermittent irrigation. Selected combinations (BF1 + 2 + 3; BF1 + 2 + 4; BF1 + 3 + 4) showed a consistent trend regarding their superiority over other treatments in terms of plant growth promotion and soil microbiological parameters. Microscopic examination of soil enrichment cultures raised from the treatments revealed their comparative abundance over native flora. A significant enhancement in terms of soil microbial biomass carbon and humus content was also recorded in these treatments. The soil enzymatic profile of the inoculated treatments involving FDA, dehydrogenase, acid phosphates, alkaline phosphatase, aryl esterase and β-glucosidase also revealed the promise of the inoculated strains. 16SrDNA sequencing, followed by BLAST analyses provided valuable information regarding the establishment of Anabaena strains. RFLP analyses of the 16SrDNA sequences of soil DNA and phylogenetic analyses vis a vis sequences of the inoculated cyanobacterial strains revealed the promise of treatments ?BF1 + 2 + 3, BF1 + 2 + 4 and BF1 + 3 + 4. Panicle weight (yield attribute) was statistically at par with the fertilizer controls 1/2N + PK and significantly higher than 1/3N + PK. To our knowledge, this represents a first report on evaluating the establishment of cyanobacterial inoculants in rice crop grown under non-flooded conditions (or intermittent irrigation) using a combination of agronomic, microbiological and soil DNA related attributes.     

Optimization of the protocols for double vaccination against Marek's disease by using commercially available vaccines: evaluation of protection, vaccine replication, and activation of T cells

Revaccination against Marek's disease is a widespread practice in some countries. The rationale of this practice is unknown, and there is no consensus in the protocols. Recently, we have demonstrated that administration of the first vaccine at 18 days of embryonation followed by a more protective second vaccine at hatch (18ED/1d) reproduced systematically the benefits of revaccination under laboratory conditions. Here, we have used the same model to optimize the revaccination protocols by using currently available vaccines and to determine whether two features associated with Marek's disease vaccine-induced protection (activation of T cells and replication of vaccine virus) are involved in the revaccination protocols. Protection conferred by three revaccination protocols (turkey herpesvirus [HVT] 18ED/HVT+SB-1 1d, HVT 18ED/CVI988 1d, and HVT+SB-1 18ED/ CVI988 1d) was evaluated. Revaccination protocols also were compared with single vaccination protocols (HVT 18ED, HVT+SB-1 18ED, HVT+SB-1 1d, CVI988 18ED, and CVI988 1d). Our results demonstrated that it is possible to improve efficacy of the currently available vaccines by using them in revaccination programs. Administration of HVT 18ED/CVI988 1d and HVT+SB-1 18ED/CVI988 1d were the two protocols that conferred the highest protection against a very early challenge (2 days of age) with very virulent plus Marek's disease virus strain 648A. In a separate experiment, we evaluated vaccine replication and activation of T cells in single and revaccination protocols. Our results demonstrated that replication of the second vaccine, although decreased compared with single vaccination, could be detected at 3 days (HVT, CVI988) or at 6 days (SB-1). Administration of the first vaccine (HVT) at 18ED resulted in a high percentage of activated T cells. Administration of a second vaccine (either HVT-SB-1 or CVI988) at 1d resulted in increased intensity of MHC-II stain in activated T cells.     

Isolation and evaluation of putative probiotic strains from different teleost to prevent Pseudomonas aeruginosa infection in Cyprinus carpio

Probiotics renowned as valuable microbes serve as a potential alternative to control diseases in aquaculture and are considered as an efficient and environment‐friendly approach to reduce the use of antibiotics. The present study aims at the isolation of putative probiotic bacteria from the intestinal tract of different fish species from the Doaba region of Punjab, India. In this study, isolated bacterial strains were characterized based on their morphological, biochemical and molecular characterization by 16S rRNA gene sequencing, followed by in vitro evaluation of different selection parameters described in FAO/WHO guidelines. A total of 169 different bacterial strains were isolated from the gastrointestinal tract of 52 different fish species. After in vitro evaluation, out of 169 bacterial strains only five bacteria (S3, S7, BDK2', BDK7 and BDK9) identified as Enterococcus and Bacillus species showed antagonistic activity against the fish pathogen Pseudomonas aeruginosa (MTCC 4 673). These isolates were screened based on their response towards bile tolerance, pH tolerance, adhesion and drug susceptibility to different antibiotic discs. And, the in vivo results indicated improved growth and survival against the infection (P. aeruginosa) after oral administration of the probiotics. The observations of in vitro and in vivo evaluation indicate that these isolated probiotic strains serve as effective probiotics and can be used as a novel and safe treatment to cure current issues in aquaculture.     

Ultralow thermal conductivity in disordered, layered WSe2 crystals

The cross-plane thermal conductivity of thin films of WSe2 grown from alternating W and Se layers is as small as 0.05 watts per meter per degree kelvin at room temperature, 30 times smaller than the c-axis thermal conductivity of single-crystal WSe2 and a factor of 6 smaller than the predicted minimum thermal conductivity for this material. We attribute the ultralow thermal conductivity of these disordered, layered crystals to the localization of lattice vibrations induced by the random stacking of two-dimensional crystalline WSe2 sheets. Disordering of the layered structure by ion bombardment increases the thermal conductivity.     

Identification of market adulterants in East Indian sandalwood using DNA barcoding

Context

East Indian sandalwood (Santalum album L.) in commercial markets is highly prone to adulteration. A number of cases were registered with regard to the adulteration of East Indian sandalwood, but the lack of technical tools for the precise species identification of the source wood stalled most of the court cases.

Aims

The standard DNA barcode regions, the rbcL, matK and trnH-psbA chloroplast genomic sequences recommended by the Consortium of Barcode of Life (COBOL) were analysed to distinguish wood adulterants of East Indian sandalwood.

Methods

Standard polymerase chain reactions with COBOL recommended primers were performed for all three barcode loci. The PCR products after gel elution were sequenced and alignments were performed using CLUSTALX.

Results

Single nucleotide polymorphisms (SNPs) identified with rbcL and trnH-psbA sequences of Erythroxylum monogynum Roxb. as well as with matK sequences of Osyris wightiana Wall ex. Wight could be efficiently utilized for the detection/monitoring of East Indian sandalwood adulterants. Among the two common adulterants O. wightiana and E. monogynum, the former was more similar to S. album and grouped together in the dendrogram.

Conclusion

The study recommends the exploitation of DNA barcoding technique using standard barcodes to trace sandalwood timber adulterants.     

Fingerprinting in cucumber and melon (<Emphasis Type="Italic">Cucumis</Emphasis> spp.) Genotypes using morphological and ISSR markers

In the present investigation, 13 Cucumis genotypes from different geographical areas of India were screened for genetic diversity using 19 morphological traits and 15 ISSR primers. The analysis of morphological traits grouped the accessions into six clusters. Cluster V contained the maximum number of genotypes namely Kanivellari, Long Green, Andaman Local, Perundurai Local, and Sempatti Local. Clusters I and VI contained the minimum number of genotypes. Among all the characters, the highest mean value was observed in fruit length (23.38) and the lowest mean value was observed in stripes on the blossom end (1.31). The 15 ISSR primers generated 109 polymorphic alleles. The average number of ISSR alleles generated was 8.3 per primer and the level of polymorphism was 87.20%. The ISSR primer UBC 825 was highly informative with a PIC value of 0.8934. The 13 genotypes were grouped into six clusters based on ISSR markers. Cluster III contained the maximum number of genotypes, namely Kanivellari, Sankagiri Local, Perundurai Local, Long Melon, and Sempatti Local, while Clusters I, II, IV, and V (Karur Local, Andaman Local, Edapaddi Local, and N 78, respectively) contained the minimum number of genotypes. The ISSR profile generated genotypes specific allele namely, UBC 812_700bp and UBC 812_1000bp for Cluster VI which contained Cucumis genotypes collected from the northern part of India. Similarly, UBC 808 produced specific allele UBC 808_650bp formed in Cluster III which contained genotypes collected from Tamil Nadu and Kerala.     

Stem and leaf rust resistance in wild relatives of wheat with D genome (Aegilops spp.)

Resistance to stem rust and leaf rust in five D genome species of wheat viz., 267 accessions of Aegilops tauschii Coss., 39 of Ae. cylindrica Host, 17 of Ae. ventricosa Tausch, 4 of Ae. crassa Boiss. and 8 of Ae. juvenalis (Thell.) Eig were evaluated at adult plant stage. Two hundred and thirty nine (90 %) accessions of Ae. tauschii, 30 (77 %) of Ae. cylindrica, 16 (94 %) of Ae. ventricosa, 3 (75 %) of Ae. crassa Boiss. and 5 (62.5 %) of Ae. juvenalis were resistant to stem rust pathotypes prevalent in South India at Wellington under field condition. Invariably, all the accessions of the five species were resistant to leaf rust pathotypes. Quantitative measurement of disease using area under the disease progress curve revealed the slow progress of disease in the resistant accessions compared to susceptible check (Agra Local). Since all the five species have D genome, it could be concluded that the genes present in D genome might play a vital role in leaf rust resistance, but in case of stem rust resistance wide range of differential response was noticed. Among the species evaluated, Ae. tauschii was exploited to a larger extent, followed by Ae. ventricosa and Ae. cylindrica for leaf and stem rust resistance because of the homology of D genome with hexaploid bread wheat. While, Ae. crassa and Ae. juvenalis could not be utilized so far, possibly due to partial homology which makes the transfer of traits difficult. So, these species have considerable potential as a source of rust resistance and may enhance the existing gene pool of resistance to stem and leaf rusts.