4,867 research outputs found
Genetic analysis for various yield components and gluten content in bread wheat (Triticum aestivum L.)
Genetic analysis was carried out in 55 genotypes (10 parents and 45 F1s) through diallel mating design excluding reciprocals in bread wheat (Triticum aestivum L.). Analysis of variance showed wide range of variability among the breeding material for all the traits under study. The highest value of phenotypic coefficient of variation (PCV) and genotypic coefficient of variation (GCV) were recorded for grain yield (PCV= 9.07 and GCV= 8.08). Highest heritability with genetic advance was recorded for grain yield (h2=10.60 and GA=14.84), therefore selection will be effective based on grain yield for further study. Grains per spike (gr = 0.77 and pr = 0.67) and spikelets per spike (gr= 0.63 and pr = 0.52) were found significantly correlated (at <1 % level of significance) with grain yield whereas gluten content showed nonsignificant but positive correlation with grain yield at both genotypic as well as phenotypic level. Similarly, path coefficient analysis estimates for gluten content (g= 0.08 and p= 0.03) and grains per spike (g=0.36 and p=0.23) showed high positive direct effects on grain yield therefore these traits may be used as an index for selection to high yield in bread wheat genotypes
Estimates of genetic components and regression analysis for grain yield and various morphological traits in bread wheat (Triticum aestivum L.)
The present study was conducted to estimate the gentic components and regression analysis for grain yield and various morphological traits in bread wheat involving 10 parents and their 45 F1s (half diallel) during 2012- 13 and 2013-14. Significant additive (D) and dominance (H1) variance for the traits indicated that expression of these traits is control by both additive and dominance gene action. Average degree of dominance (H1/D)1/2 were more than unity for the traits (peduncle length, flag leaf area, productive tillers, biological yield, grain yield, harvest index) indicating the preponderance of over dominance gene action. The estimates of h2 were positive and significant for days to ear emergence, peduncle length, productive tillers, biological yield and grain yield indicated dominance of genetic components in F1s. Positive and significant values of F were estimated for days to ear emergence, days to 50% flowering, spike length, flag leaf area and grain yield in F1s indicating the preponderance of dominance and positive genes in the parents involved. The theoretical value (0.25) of (H2/4H1) for all the traits indicated asymmetrical distribution of positive and negative genes. The proportion of dominant and recessive alleles indicated presence of dominant alleles in the parents. The traits showing more than 30% narrow sanse heritability could be rewarding for further improvement in grain yield in bread wheat. Regression analysis indicated that the traits (days to ear emergence, days to 50% flowering, peduncle length, flag leaf area, productive tillers, harvest index, biological yield and grain yield) control by over dominance type of gene action. The parent RAJ 4246 contained maximum dominant genes for days to ear emergence and days to 50% flowering; HD 2733 for spike length and flag leaf area and HD 2824 for productive tillers, biological yield and grain yield used as donors in multiple traits breeding programme to develop high yielding wheat genotypes
Identification of heterotic cross combinations for various agromorphological and some quality traits in bread wheat (Triticum aestivum L.)
A study was conducted to identify the best heterotic cross for various agromorphological and some quality traits involving 10 parents and their 45 F1s excluding reciprocals during 2012-13 and 2013-14. The higher magnitude of heterosis for all the agromorphological and quality traits was not expressed in a single cross combination. It varied from cross to cross due to diverse genetic background of their parents. The highest heterobeltiosis (35.68%, 11.11%, 11.44%), average heterosis (38.97%, 9.13%, 10.26%) and standard heterosis (31.09%, 7.84%, 10.41%) for grain yield, spikelets per spike and grains per spike respectively, was showed by HD 3095 x RAJ 4246 and this cross also showed highly significant (at <1% level of significant) heterosis for biological yield, flag leaf area, spike length and productive tillers. Whereas PBW 435 x RAJ 4246 were common for gluten content (8.52% and 7.72%), grain yield (33.11% and 33.64%), productive tillers (16.15% and 13.53%) and biological yield (36.27% and 21.98%) which showed superior average heterosis and heterobeltiosis respectively, therefore, these crosses may be exploit-ed in a national hybrid wheat breeding programme may offer genetic improvement in breeding for higher grain yield, agromorphological and quality traits in bread wheat. The presence of high heterosis for yield contributing compo-nents is not only for developing hybrids through exploitation of heterosis but also helps to produce transgressive segregants for developing of superior homozygous lines
LbCS navigation controllers of Twining Lagrangian swarm individuals
This paper presents stabilizing velocity controllers for the individuals of two Lagrangian swarms, which navigates from their initial configuration space to their final configuration space, ensuring intra and inter swarm individual collision avoidance. The motion of the individuals is based on Reynold's rules of separation, alignment, and cohesion. Using the three pillars (safety, shortest and smoothest path) of Lyapunov based control scheme (LbCS), the velocity controllers of the individuals of the two swarms are derived from multiple Lyapunov functions. The effectiveness of the controllers is validated through computer simulations
Navigation of an n - link revolute robotic arm via hierarchal landmarks
This paper presents a dynamic n-link revolute robotic arm that can perform a sequence of tasks and navigate via hierarchal landmarks to its target. The stability condition with multiple Lyapunov functions for switched systems is considered. The multiple Lyapunov functions are formulated from the Lyapunov-based Control Scheme (LbCS) as a tool for analyzing Lyapunov stability. A new set of switched nonlinear, time-invariant, continuous, and stabilizing velocity controllers of the proposed R n robotic arm are developed
Development of Nano SiO2 Particles Dispersed Shape Memory Epoxy Composites
Thermo responsive shape memory epoxy based composites are being investigated for their excellent mechanical and thermal properties. In present study the thermosetting epoxy containing different composition of SiO2 nano particles ranging from 1 to 4 wt. % have been prepared through solvent casting route. Developed composites have been studied for grain analysis, FTIR, shape recovery, impact strength and hardness. Addition of 3 wt. % SiO2 improves hardness and impact strength significantly. Average grain size of SiO2 particles increase at higher wt. % of SiO2 in polymer matrix due to agglomeration of nanoparticles
Wigner delay time from a random passive and active medium
We consider the scattering of electron by a one-dimensional random potential
(both passive and active medium) and numerically obtain the probability
distribution of Wigner delay time (). We show that in a passive medium
our probability distribution agrees with the earlier analytical results based
on random phase approximation. We have extended our study to the strong
disorder limit, where random phase approximation breaks down. The delay time
distribution exhibits the long time tail () due to resonant states,
which is independent of the nature of disorder indicating the universality of
the tail of the delay time distribution. In the presence of coherent absorption
(active medium) we show that the long time tail is suppressed exponentially due
to the fact that the particles whose trajectories traverse long distances in
the medium are absorbed and are unlikely to be reflected.Comment: 13 pages RevTex, 5 EPS figures included, communicated to PR
Lyapunov - based controllers of an n - link Prismatic Robot Arm
This research provides a generalized stabilizing velocity controllers for planer robot arm with a base rotational joint and n∈N translation joint for navigation. The end-effector of the planer robot arm has to navigate from an initial to a final configuration space in an environment, which cluttered with obstacles. The velocity controllers are developed from a Lyapunov function, total potentials, designed via Lyapunov-based control scheme (LbCS) falling under the classical approach of artificial potential fields method. The effectiveness of the controllers is validated through computer simulations
A car - like mobile manipulator with an n - link Prismatic Arm
In this research, the Lyapunov based Control Scheme (LbCS) is used to solve the motion planning and control problem of a car-like mobile robot with a long extendible prismatic arm comprising n∈N links. The prismatic arm consists of a base revolute joint and n∈N translational joints, and is mounted on the wheeled car-like mobile platform. The kinematic model of the manipulator is developed, and velocity based algorithms are utilized to firstly, move the car-like base from an initial position to its pseudo-target and secondly, maneuver the end-effector to its designated target, taking into account the restrictions and limitations of the prismatic links and the steering control laws of the system. Computer simulations are presented to illustrate the effectiveness of the proposed control laws
Analysis of conformational variation in macromolecular structural models
Experimental conditions or the presence of interacting components can lead to variations in the structural models of macromolecules. However, the role of these factors in conformational selection is often omitted by in silico methods to extract dynamic information from protein structural models. Structures of small peptides, considered building blocks for larger macromolecular structural models, can substantially differ in the context of a larger protein. This limitation is more evident in the case of modeling large multi-subunit macromolecular complexes using structures of the individual protein components. Here we report an analysis of variations in structural models of proteins with high sequence similarity. These models were analyzed for sequence features of the protein, the role of scaffolding segments including interacting proteins or affinity tags and the chemical components in the experimental conditions. Conformational features in these structural models could be rationalized by conformational selection events, perhaps induced by experimental conditions. This analysis was performed on a non-redundant dataset of protein structures from different SCOP classes. The sequence-conformation correlations that we note here suggest additional features that could be incorporated by in silico methods to extract dynamic information from protein structural models
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