Novel sources of variation in grain yield, components and mineral traits identified in wheat amphidiploids derived from thinopyrum bessarabicum (Savul. & rayss) Á. löve (poaceae) under saline soils in India

© 2020 by the authors. Licensee MDPI, Basel, Switzerland. Salt-affected soils constrain wheat production globally. A wild wheat species, Thinopyrum bessarabicum (Savul. & Rayss) Á. Löve (Poaceae), and its derivatives are tolerant of high external NaCl concentrations but have not been tested yet in field conditions. The aim of this study was to study the performance of amphidiploids derived from T. bessarabicum for grain yield (GYD), yield components and grain mineral composition traits under normal and saline soil conditions. Field experiments were conducted at Karnal (pH(water) = 7.3) and Hisar (pH(water) = 8.3) sites in 2014–2015 and 2015–2016 in India. Grain samples were analysed using inductively coupled plasma–mass spectrometry (ICP-MS). Yield and yield component traits of amphidiploids were typically greater at Karnal than Hisar. The GYD was greater at Karnal (1.6 t ha−1) than Hisar (1.2 t ha−1) in 2014–2015. However, GYD was greater at Hisar (1.7 t ha−1) than Karnal (1.1 t ha−1) in 2015–2016. Mean grain zinc (Zn) concentration of eight amphidiploids, averaged across sites and years, varied from 36 to 43 mg kg−1. Some amphidiploids derived from T. bessarabicum showed greater GYD and grain Zn concentration under saline soils (Hisar) than normal soils (Karnal). These might be potential new sources for the development of salt-tolerant wheat varieties with increased grain Zn concentration under salt-affected soils

Plant gene bank collections - sources of variation in health substances

Gene banks and national plant genetic resources programmes have been established to conserve genetic resources of domesticated plants. Variation of the beneficial health substances found in plants is the result of growing conditions (environment) and genes directing the growth (genotype)

Novel sources of variation in grain Zinc (Zn) concentration in bread wheat germplasm derived from Watkins landraces

A diverse panel of 245 wheat genotypes, derived from crosses between landraces from the Watkins collection representing global diversity in the early 20th century and the modern wheat cultivar Paragon, was grown at two field sites in the UK in 2015-16 and the concentrations of zinc and iron determined in wholegrain using inductively coupled plasma-mass spectrometry (ICP-MS). Zinc concentrations in wholegrain varied from 24-49 mg kg-1 and were correlated with iron concentration (r = 0.64) and grain protein content (r = 0.14). However, the correlation with yield was low (r = -0.16) indicating little yield dilution. A sub-set of 24 wheat lines were selected from 245 wheat genotypes and characterised for Zn and Fe concentrations in wholegrain and white flour over two sites and years. White flours from 24 selected lines contained 8-15 mg kg-1 of zinc, which was positively correlated with the wholegrain Zn concentration (r = 0.79, averaged across sites and years). This demonstrates the potential to exploit the diversity in landraces to increase the concentration of Zn in wholegrain and flour of modern high yielding bread wheat cultivars

A Conceptual Framework for Studying the Sources of Variation in Program Effects

Evaluations of public programs in many fields reveal that (1) different types of programs (or different versions of the same program) vary in their effectiveness, (2) a program that is effective for one group of people might not be effective for other groups of people, and (3) a program that is effective in one set of circumstances may not be effective in other circumstances. This paper presents a conceptual framework for research on such variation in program effects and the sources of this variation. The framework is intended to help researchers -- both those who focus mainly on studying program implementation and those who focus mainly on estimating program effects -- see how their respective pieces fit together in a way that helps to identify factors that explain variation in program effects and thereby support more systematic data collection on these factors. The ultimate goal of the framework is to enable researchers to offer better guidance to policymakers and program operators on the conditions and practices that are associated with larger and more positive effects

Analysis of load displacement in grape harvesters and corresponding effect on dynamic weighing system under laboratory conditions

Harvester bin dynamic weighing systems are affected by a number of sources of variation such as field slopes and load displacement. In grape harvesters, the nature of the material (wine grapes and wine grape juice) and its relative composition can vary significantly. Laboratory tests were carried out using hydrogel spheres and water to simulate field dynamic conditions during harvest. This paper quantifies the sources of variation, submitting an instrumented grape harvester to graduated inclination under shaking conditions. Load displacement is characterized using image analysis from recorded movies on four different pitch axis motions of the machine: front to horizontal, horizontal to rear, rear to horizontal and horizontal to front. Differences in the displacement of the load in relation to the machine inclination and to the load composition have been addressed

Addressing potential sources of variation in several non-destructive techniques for measuring firmness in apples

Measurements of firmness have traditionally been carried out according to the Magness Taylor (MT) procedure; using a texture analyser or penetrometer in reference texture tests. Non-destructive tests like the acoustic impulse response of acoustic firmness sensors (AFSs), a low-mass impact firmness sensor Sinclair International (SIQ-FT) and impact test (Lateral Impact – UPM) have also been used to measure texture and firmness. The objectives of this study were to evaluate the influence of different sources of variation in these three non-destructive tests and to evaluate their respective capabilities of discriminating between fruit maturity at two different harvest dates, turgidity before and after dehydration treatment and ripening after different storage periods. According to our results, fruit studied an unexpected AFS trend with turgidity. Contact measurements (Lateral Impact – UPM and SIQ-FT) appeared highly sensitive to changes in turgidity, but were less able to follow changes in ripening caused by storage period. Contact measurements were suitable for detecting differences between fruits from different harvest dates and showed higher correlation coefficients with reference texture tests than acoustic measurements. The Lateral Impact – UPM test proved better at separating fruits according to turgidity than the SIQ-FT instrumen

Sources of variation in Affymetrix microarray experiments

BACKGROUND: A typical microarray experiment has many sources of variation which can be attributed to biological and technical causes. Identifying sources of variation and assessing their magnitude, among other factors, are important for optimal experimental design. The objectives of this study were: (1) to estimate relative magnitudes of different sources of variation and (2) to evaluate agreement between biological and technical replicates. RESULTS: We performed a microarray experiment using a total of 24 Affymetrix GeneChip(® )arrays. The study included 4(th )mammary gland samples from eight 21-day-old Sprague Dawley CD female rats exposed to genistein (soy isoflavone). RNA samples from each rat were split to assess variation arising at labeling and hybridization steps. A general linear model was used to estimate variance components. Pearson correlations were computed to evaluate agreement between technical and biological replicates. CONCLUSION: The greatest source of variation was biological variation, followed by residual error, and finally variation due to labeling when *.cel files were processed with dChip and RMA image processing algorithms. When MAS 5.0 or GCRMA-EB were used, the greatest source of variation was residual error, followed by biology and labeling. Correlations between technical replicates were consistently higher than between biological replicates

Practicing Your Protocols

The purpose of this resource is to have students learn to use the hydrology instruments and collect the hydrology data accurately. In the classroom, students practice using the instruments or kits for protocols, exploring the range of measurements and sources of variation and error. Educational levels: Primary elementary, Intermediate elementary, Middle school, High school

Threshold queueing describes the fundamental diagram of uninterrupted traffic

Queueing due to congestion is an important aspect of road traffic. This paper provides a brief overview of queueing models for traffic and a novel threshold queue that captures the main aspects of the empirical shape of the fundamental diagram. Our numerical results characterises the sources of variation that influence the shape of the fundamental diagram

Sheer Class? The Extent and Sources of Variation in the UK Graduate Earnings Premium

In this paper, we use the individual-level USR data for the whole population of 1993 leavers from the 'old' universities of the UK to investigate the determinants of graduate occupational earnings. Among other results, we find that there are significant differences in the occupational earnings of leavers, according to: university attended, subject studied, degree class awarded, and Social Class of family background, ceteris paribus. Our results suggest that there is likely to be significant variation around the average rate of return to a first degree.graduate earnings, degree class, subject