Higher fine-scale genetic structure in peripheral than in core populations of a long-lived and mixed-mating conifer - eastern white cedar (Thuja occidentalis L.)

<p>Abstract</p> <p>Background</p> <p>Fine-scale or spatial genetic structure (SGS) is one of the key genetic characteristics of plant populations. Several evolutionary and ecological processes and population characteristics influence the level of SGS within plant populations. Higher fine-scale genetic structure may be expected in peripheral than core populations of long-lived forest trees, owing to the differences in the magnitude of operating evolutionary and ecological forces such as gene flow, genetic drift, effective population size and founder effects. We addressed this question using eastern white cedar (<it>Thuja occidentalis</it>) as a model species for declining to endangered long-lived tree species with mixed-mating system.</p> <p>Results</p> <p>We determined the SGS in two core and two peripheral populations of eastern white cedar from its Maritime Canadian eastern range using six nuclear microsatellite DNA markers. Significant SGS ranging from 15 m to 75 m distance classes was observed in the four studied populations. An analysis of combined four populations revealed significant positive SGS up to the 45 m distance class. The mean positive significant SGS observed in the peripheral populations was up to six times (up to 90 m) of that observed in the core populations (15 m). Spatial autocorrelation coefficients and correlograms of single and sub-sets of populations were statistically significant. The extent of within-population SGS was significantly negatively correlated with all genetic diversity parameters. Significant heterogeneity of within-population SGS was observed for 0-15 m and 61-90 m between core and peripheral populations. Average <it>Sp</it>, and gene flow distances were higher in peripheral (<it>Sp </it>= 0.023, σ_g= 135 m) than in core (<it>Sp </it>= 0.014, σ_g= 109 m) populations. However, the mean neighborhood size was higher in the core (<it>Nb </it>= 82) than in the peripheral (<it>Nb </it>= 48) populations.</p> <p>Conclusion</p> <p>Eastern white cedar populations have significant fine-scale genetic structure at short distances. Peripheral populations have several-folds higher within-population fine-scale genetic structure than core populations. Anthropogenic disturbances and population fragmentation presumably have significant effects on fine-scale genetic structure in eastern white cedar. Core populations have higher neighborhood size than peripheral populations, whereas gene flow distances are higher in peripheral than in core populations. The results of our study contribute to the knowledge of poorly-understood spatial genetic structure of core versus peripheral populations in plants. As well, the information is of significance for conservation of genetic resources of eastern white cedar and perhaps of other long-lived forest trees with mixed-mating system.</p

Production economics and resource use efficiency of tomato under open field condition in Kapilvastu, Nepal

A study was conducted in Kapilvastu district with an objective to analyze the production economics and resource use efficiency of tomato production under open field condition. Altogether ninety tomato growers were purposely selected for household survey. Primary data were collected using pre-tested interviews and focus group discussion with tomato farmers and stakeholders. Data was analyzed using SPSS and STATA, and socio-demographic characteristics, Cobb-Douglas production function and resource use efficiency of the tomato farmers was studied. The tomato production in the studied site was found to be a labor-intensive venture as cost incurred for labor was about 39 percent of the total cost with gross margin of NRs. 7255.10 per kattha and net profit of NRs. 5464.1 per kattha. Cobb-Douglas production function analysis showed positive and significant relationship of cost on labor, seed, farm yard manure, inorganic fertilizer and micronutrients and other associated expenses with the gross income. The returns to scale of 1.02 indicated increasing returns to scale whereas resource use efficiency values indicated all input resources were underutilized in tomato production

Distribution pattern and heavy metal accumulation in lichens of Bangalore city with special reference to Lalbagh garden

Occurrence of 30 species of lichens belonging to 19 genera and 15 families in 12 localities of Bangalore city is reported. The Indian Institute of Science (IISc) campus and Lalbagh garden record the maximum number of 24 and 18 species of lichens respectively, which can be directly attributed to the presence of a variety of trees in the area providing diverse substrate for lichen growth. Heavy-metal accumulation in few prominent lichens of some localities is also analysed. Cr and Pb were maximum in Chrysothrix candelaris (L.) Laundon, at AMCO Batteries area with 95.29 and 623.95 μg g-1 dry wt. respectively. Fe and Cu were maximum in Bulbothrix isidiza (Nyl.) Hale and Pyxine petricola Nyl. at IISc campus with 22721 and 338.12 μg g-1 dry wt. respectively, while Lecanora perplexa Brodo at Lalbagh garden has 531.5 μg g-1 dry wt. of Zn. The lichen flora of Lalbagh garden is compared to an earlier enumeration. It is interesting to note that in the last 18 years lichen flora of the area has changed significantly, as only four species were common between the two studies. The fast pace of urbanization together with air pollution may probably be the reason for the change in lichen flora of this area. The present number, type of lichen and the level of metals accumulated will be a record for conducting future biomonitoring studies in this fastest-growing city of India

Effect of different nitrogen levels on yield and yield attributes of different rice varieties in DDSR condition at Kanchanpur, Nepal

An experiment on the effect of different nitrogen levels on yield and yield attributes of different rice varieties was conducted in Kanchanpur, Nepal, from March 2021 to July 2021. The experiment was laid in randomized complete block design with two factors: nitrogen levels and rice varieties, each factor having three levels (Nitrogen: 60kg/ha, 120kg/ha, and 180kg/ha and rice varieties: Hardinath 1, Hardianth 3 and Chaite 5) resulting in nine treatment combinations. Rice seeds were sown directly in experimental plots under the dry condition on March 24, 2021. The plant spacing was 20x20cm^2. Growth parameters, grain yield, and yield attributing traits of rice were recorded. The statistical results revealed significant differences between the treatments regarding agronomical parameters, yield attributing characters, and grain yield. The results indicated that the 180 kg/ha level of N application contributes to the higher plant height (74.502 cm), the number of tillers (1101.667), effective tillers (577.222), filled grain per panicle (116.490), panicle length (25.241 cm), grain yield (4.7 ton/ha) and straw yield (10.564 ton/ha). Among the varieties, Hardinath 3 produced significantly higher plant height (79.68 cm), panicle length (25.68cm), sterility percentage, and 1000 grain weight (24.60g) as compared to Hardinath 1 and Chapter 5, respectively. However, yield and yield attributing characters like grain yield, straw yield, effective tillers, and filled grains per panicle were significantly higher in Chaite 5. Therefore, a nitrogen level of 180 kg/ha and variety Chaite5 may be used for better productivity in Kanchanpur, Nepal

Biopolymer: A Novel Bioexcipient

Polymers are the key material in design of drug delivery systems. These have been shown as the spine for drug development process. These accept an essential part in rising of novel drug delivery systems to crush different intricacies in drug delivery. These are used for controlling the appearance of the drug in needed manner. The hydrophilic and lipophilic polymers are the most ideal choice for getting the ideal conveyance in controlled, manner at the target sites. Isolated of this, these fabricated and semisynthetic polymers are made by different chemical reactions and purification measures. Since these are prepared by different unit operations which are costly. By and by days different investigates are being examined for avoiding the characteristic, physiological and reasonable issues related with the synthetic and semisynthetic polymers. So an alternative rather than synthetic and semisynthetic polymers are being investigated having interest, probability, and any leftover benefits with least troublesome ramifications for environment and physiology of the people. One of the alternatives as opposed to designed and semisynthetic polymers is biopolymers which have pulled in the thought of researchers by using an economical procedures. Biopolymers are novel, adroit and sharp polymers which have been confined from various basic sources. Biopolymers isolated from natural sources might be utilized as novel excipients having a polymeric nature. These isolated biopolymers have superb bioretardant, bio stabilizer, and mucoadhesive properties. These have the brilliant film-framing capacity and biocompatibility properties. The isolated bio-polymers have great drug release rate controlling capacities. Since these are biodegradable and might be utilized as an option in contrast to standard manufactured synthetic and semisynthetic polymers. The isolated biopolymer shows critical biodegradable, mucoadhesive, filmability, and retardability properties which are like properties of standard polymers, may be the alternative in design of novel drug delivery system design

Different isoforms of starch-synthesizing enzymes controlling amylose and amylopectin content in rice (Oryza sativa L.)

Starch, composed of amylose and amylopectin, greatly influences rice cooking and textural quality, which in turn is controlled by various isoforms of several enzymes. Activity of one or more isoforms of starch synthesizing enzymes results in various forms of starch structure based on the amylopectin chain length, average external, internal and core chain length distribution and hence result in varying physicochemical and cooking quality. Since the synthesis of starch is highly complex, it is crucial but essential to understand its biosynthetic pathway, starch structure and its effects on the physicochemical properties that control eating and cooking quality; and alongside conduct research on gene/QTL mapping for use in marker-assisted selection (MAS) with a view to improve and select cultivars with most desirable range and class of rice starch properties. This article presents the updates on current understanding of the co-ordination among various enzymes/isoforms towards rice starch synthesis in endosperm and their effect on rice grain physico-chemical, cooking and eating qualities. The efforts in identifying regions responsible for these enzymes by mapping the gene/QTLs have provided a glimpse on their association with physic-chemical and cooking properties of rice and hence, improvement is possible by modifying the allelic pattern, resulting in down or nil regulation of a particular enzyme. The clear understanding of the tissue specific co-ordination between enzyme isoforms and their subsequent effect in controlling eating and cooking properties will enhance the chances to manipulate them for getting desired range of amylose content (AC) and gelatinization temperature (GT) in improved cultivars through combining desired alleles through MAS

A multiwavelength view of the ISM in the merger remnant Fornax A galaxy

We present multi-wavelength imagery of the merger remnant galaxy NGC 1316 with an objective to study the content of dust and its association with the other phases of the ISM. Color-index maps as well as extinction maps derived for this galaxy reveal an intricate and complex dust morphology in NGC 1316, i.e., in the inner part it exists in the form of a prominent lane while at about 6--7\,kpc it apparently takes an arc-like pattern extended along the North-East direction. In addition to this, several other dust clumps and knots are also evident in this galaxy. Dust emission mapped using \textit{Spitzer} data at 8 $\mu$m indicates even more complex morphological structures of the dust in NGC1316. The extinction curve derived over the optical to near-IR bands closely follows the standard Galactic curve suggesting similar properties of the dust grains. The dust content of NGC 1316 estimated from optical extinction is $\sim$ 2.13$\times\, 10^5$ \Msun. This is a lower limit compared to that estimated using the IRAS flux densities $\sim$ 5.17$\times\, 10^6$ \Msun\, and flux densities at 24$\mu$m, 70$\mu$m and 160 $\mu$m from MIPS $\sim$ 3.2$\times\, 10^7$ \Msun. High resolution \textit{Chandra} observations of this merger remnant system have provided with an unprecedented view of the complex nature of hot gas distribution in NGC 1316 which closely matches the morphology of ionized gas and to some extent with the dust also. X-ray color-color plot for the resolved sources within optical D$_{25}$ extent of NGC 1316 has enabled us to separate them in different classes.Comment: 17 pages, 8 figures, Accepted for publication in the RA

Long non-coding RNA-mediated epigenetic response for abiotic stress tolerance in plants

Plants perceive environmental fluctuations as stress and confront several stresses throughout their life cycle individually or in combination. Plants have evolved their sensing and signaling mechanisms to perceive and respond to a variety of stresses. Epigenetic regulation plays a critical role in the regulation of genes, spatiotemporal expression of genes under stress conditions and imparts a stress memory to encounter future stress responses. It is quintessential to integrate our understanding of genetics and epigenetics to maintain plant fitness, achieve desired genetic gains with no trade-offs, and durable long-term stress tolerance. The long non-coding RNA >200 nts having no coding potential (or very low) play several roles in epigenetic memory, contributing to the regulation of gene expression and the maintenance of cellular identity which include chromatin remodeling, imprinting (dosage compensation), stable silencing, facilitating nuclear organization, regulation of enhancer-promoter interactions, response to environmental signals and epigenetic switching. The lncRNAs are involved in a myriad of stress responses by activation or repression of target genes and hence are potential candidates for deploying in climate-resilient breeding programs. This review puts forward the significant roles of long non-coding RNA as an epigenetic response during abiotic stresses in plants and the prospects of deploying lncRNAs for designing climate-resilient plants

Improvement of two traditional Basmati rice varieties for bacterial blight resistance and plant stature through morphological and marker-assisted selection

Bacterial blight (BB) is a major production threat to Basmati, the aromatic rice prized for its unique quality. In order to improve the BB resistance of two elite, traditional BB-susceptible Basmati varieties (Taraori Basmati and Basmati 386), we utilized the strategy of limited marker-assisted backcrossing for introgression of two major BB resistance genes, Xa21 and xa13, coupled with phenotype-based selection for improvement of their plant type and yield. Improved Samba Mahsuri, an elite high-yielding, fine-grain-type BB-resistant rice variety served as donor for BB resistance. Backcross-derived improved Basmati lines at BC1F5 possessing a single resistance gene (i.e. either Xa21 or xa13) displayed moderate resistance to BB, while lines possessing both Xa21 and xa13 showed significantly higher levels of resistance. Two-gene pyramid lines (Xa21 + xa13) possessing good grain and cooking quality similar to their respective traditional Basmati parents, short plant stature (<110 cm plant height) and higher grain yield than the recurrent parent(s) were identified and advanced. This work demonstrates the successful application of marker-assisted selection in conjunction with phenotype-based selection for targeted introgression of multiple resistance genes into traditional Basmati varieties along with improvement of their plant stature and yield