Plant genomics in lentil breeding: development of a cDNA-based rapid screening method for Ascochyta blight resistance in lentil (Lens culinaris L.)

Non-Peer ReviewedAscochyta blight causes severe crop losses in temperate lentil production areas around the world, including Saskatchewan. At present there is no reliable system available to breeders for identifying blight resistant lentil lines. We are trying to develop a reliable, high throughput and low cost cDNA based system for screening lentil germplasm for polygenic resistance to Ascochyta blight. We have chosen the Ascochyta blight susceptible lentil variety Richlea and the closely related resistant breeding line 1156-2-17A for this study. Lentil plants were inoculated with spore suspensions of Ascochyta under conditions that clearly showed the difference in disease resistance between these lines. Tissue collected from resistant and susceptible lines at different times after inoculation will be used for extraction of total RNA–representing all the genes expressed by the plants in response to Ascochyta infection. Complementary DNA (cDNA) made from these RNA samples along with mock-inoculated controls will be visualized on poly acrylamide gels using the technique of ‘differential display’. We intend to identify the sequences of lentil genes expressed only by the resistant lines in response to Ascochyta infection and use them for developing molecular markers for the resistance trait. cDNA samples made from these plants will also be useful in developing a cDNA library of lentil tissue for future EST projects

Time-resolved observation of spin-charge deconfinement in fermionic Hubbard chains

Elementary particles such as the electron carry several quantum numbers, for example, charge and spin. However, in an ensemble of strongly interacting particles, the emerging degrees of freedom can fundamentally differ from those of the individual constituents. Paradigmatic examples of this phenomenon are one-dimensional systems described by independent quasiparticles carrying either spin (spinon) or charge (holon). Here we report on the dynamical deconfinement of spin and charge excitations in real space following the removal of a particle in Fermi-Hubbard chains of ultracold atoms. Using space- and time-resolved quantum gas microscopy, we track the evolution of the excitations through their signatures in spin and charge correlations. By evaluating multi-point correlators, we quantify the spatial separation of the excitations in the context of fractionalization into single spinons and holons at finite temperatures

Climate change impact on coastal fisheries and aquaculture in the SAARC

Observations in fisheries sciences related to climate change foresee a future with intensified climate change as a consequence of increased greenhouse gases (GHGs) in the atmosphere because of human activities. The increase in GHGs has resulted in warming of climate systems or global warming. In last 100 years, ending in 2005, the average global air temperature near the earth’s surface has been estimated to increase at the rate of 0.74 ± 0.18°C (1.33 ± 0.32°F) (IPCC, 2007). In the latest IPCC report (IPCC, 2014), climate model projections indicated that the global surface temperature during the 21st century is likely to rise a further 0.3 to 1.7°C (0.5 to 3.1°F) for their lowest emissions scenario and 2.6 to 4.8°C (4.7 to 8.6°F) for the highest emissions scenario. In the past, 15 of the 16 warmest years have occurred since 2001 and rank among the 15 warmest years in the instrumental record of global surface temperature since 1850. Climate change and associated warming is increasingly being felt in many parts of the globe including India. Climate change is predicted to lead to adverse, irreversible impacts on the earth and the ecosystem as a whole. Although it is difficult to connect specific weather events to climate change, increases in global temperature has been predicted to cause broader changes, including glacial retreat, arctic shrinkage and worldwide sea level rise (Mohanty et al., 2010).The Chaliyar river is one of the west flowing rivers of Western Ghats. It has many tributaries such as Karimpuzha. Punnappuzha, Kuruvanpuzha, Tiruanchipuzha, Cherupuzha. etc. with a catchment area of 1535 sq. km. The total discharge of the river is 7775 Mm3, The river which was in a pristine condition before 4 to 5 decades has become highly degraded in the lower stretches by the effluents of Gwalior Rayons and in the upper stretches by various anthropogenic factors like deforestation, high siltation, dynamite fishing and use of copper sulphate for fishing. During the summer months, the water in the river is very low due to high run off during the wet months

Structural basis of the carbohydrate specificities of Jacalin: an X-ray and modeling study

The structures of the complexes of tetrameric jacalin with Gal, Me-α-GalNAc, Me-α-T-antigen, GalNAcβ1-3Gal-α-O-Me and Galα1-6Glc (mellibiose) show that the sugar-binding site of jacalin has three components: the primary site, secondary site A, and secondary site B. In these structures and in the two structures reported earlier, Gal or GalNAc occupy the primary site with the anomeric carbon pointing towards secondary site A. The α-substituents, when present, interact, primarily hydrophobically, with secondary site A which has variable geometry. O-H···π and C-H···π hydrogen bonds involving this site also exist. On the other hand, β-substitution leads to severe steric clashes. Therefore, in complexes involving β-linked disaccharides, the reducing sugar binds at the primary site with the non-reducing end located at secondary site B. The interactions at secondary site B are primarily through water bridges. Thus, the nature of the linkage determines the mode of the association of the sugar with jacalin. The interactions observed in the crystal structures and modeling based on them provide a satisfactory qualitative explanation of the available thermodynamic data on jacalin-carbohydrate interactions. They also lead to fresh insights into the nature of the binding of glycoproteins by jacalin

Crystallographic identification of an ordered C-terminal domain and a second nucleotide-binding site in RecA: new insights into allostery

RecA protein is a crucial and central component of the homologous recombination and DNA repair machinery. Despite numerous studies on the protein, several issues concerning its action, including the allosteric regulation mechanism have remained unclear. Here we report, for the first time, a crystal structure of a complex of Mycobacterium smegmatis RecA (MsRecA) with dATP, which exhibits a fully ordered C-terminal domain, with a second dATP molecule bound to it. ATP binding is an essential step for all activities of RecA, since it triggers the formation of active nucleoprotein filaments. In the crystal filament, dATP at the first site communicates with a dATP of the second site of an adjacent subunit, through conserved residues, suggesting a new route for allosteric regulation. In addition, subtle but definite changes observed in the orientation of the nucleotide at the first site and in the positions of the segment preceding loop L2 as well as in the segment 102–105 situated between the 2 nt, all appear to be concerted and suggestive of a biological role for the second bound nucleotide

Quantitative genetic manipulation for nauplii size reduction of Artemia franciscana Kellogg, 1906 from Indian salinas and correlated changes in the polyunsaturated fatty acids (PUFA) profile

Thirteen generations of mass selection was carried out in a strain of Artemia franciscana collected from an Indian salina. The primary trait under selection was nauplii length, and the criteria of selection was small size. While 12.4% reduction (from 517.0±59.8 μm to 452.2±25.0 μm) was realised in the trait under selection from 13 generations, substantial increase in the polyunsaturated fatty acids (PUFA) content was realised as correlated response. The polyunsaturated fatty acid (PUFA) content showed a steady increase during the selection. The PUFA percentage in G2, G4, G6, G9, G11 and G13 generations were 21.43, 27.96, 27.19, 33.27, 36.98 and 37.25 respectively compared to 18.04 in the base generation. The content of essential polyunsaturated fatty acids such as 20:5n-3 and 22:6n-3 were also high in the selected generations, compared to the base generation indicating their nutritional superiority. The smaller nauplii with an enhanced level of PUFA, especially the essential polyunsaturated fatty acids, developed through selective breeding in the present work make it a promising strain as live feed for larviculture of marine species

Assessment of Biomass and Carbon Stocks in Mangroves of Thalassery Estuarine Wetland of Kerala, South West Coast of India

The mangrove ecosystems render many goods and services ranging from coastal protection to climate regulation. These ecosystems are also reservoirs of carbon stocks, due to their ability to sequester and store carbon in their biomass and the underlying sediment, and therefore significant in view of the climate change mitigation. The present study attempted to assess the biomass and carbon stock of mangroves of Thalassery estuarine wetland of Kerala, south-west coast of India. We assessed the carbon stocks of three carbon pools viz., above-ground, below-ground (root) and sediment. A total of eight species of mangroves were recorded from the Thalassery estuarine wetland, and of these, Avicennia officinalis was the dominant species with an average tree density of 729.37 individuals ha-1 and contributed most (45.05±23.79 t ha-1) to the total carbon. The overall mean above-ground biomass was 189.26±97.80 t ha-1, while the overall mean root biomass was 83.06±40.48 t ha-1. The estimated mean above-ground carbon was 94.63±48.90 t C ha-1, while the mean carbon stock in root and sediment were 41.53±20.24 t C ha-1 and 17.48±7.30 t C ha-1, respectively. In the present study, the estimates of mean combined C-stocks in mangrove and sediment showed that the mangroves of Thalassery estuarine wetland stored 153.64 t C ha-1 which was equivalent to 563.86 t CO2 ha-1. The mangroves of Thalassery wetland cover an area of approximately 5.8 ha and thus it can be assumed that this wetland has the potential to sequester and store 891.11 t C, equivalent to an estimated amount of 3270.37 t CO2. The study reinforces the importance of mangrove forests as useful carbon sinks and the need for protection of these critical habitats in the light of climate change mitigation

Topological dynamical quantum phase transition in a quantum skyrmion phase

Quantum skyrmionic phase is modelled in a 2D helical spin lattice. This topological skyrmionic phase retains its nature in a large parameter space before moving to a ferromagnetic phase. Next nearest-neighbour interaction improves the stability and it also causes a shift of the topological phase in the parameter space. Nonanalytic behaviour of the rate function observed, when the system which is initially in a quantum skyrmion phase is quenched to a trivial quantum ferromagnetic phase, indicates a dynamical quantum phase transition. Dynamical quantum phase transition is absent when the system initially in a skyrmion phase is quenched to a helical phase