scholarly journals Spectroscopic Estimation of N Concentration in Wheat Organs for Assessing N Remobilization Under Different Irrigation Regimes

2021 ◽  
Vol 12 ◽  
Author(s):  
Wei Li ◽  
Xiaonan Zhou ◽  
Kang Yu ◽  
Zhen Zhang ◽  
Yang Liu ◽  
...  
Keyword(s):  
Low Cost ◽  
Resistance Breeding ◽  
Hyperspectral Data ◽  
Least Squares Regression ◽  
Irrigation Regimes ◽  
N Concentration ◽  
Organ Specific ◽  
Powder Samples ◽  
N Remobilization ◽  
Highly Correlated

Nitrogen (N) remobilization is a critical process that provides substantial N to winter wheat grains for improving yield productivity. Here, the remobilization of N from anthesis to maturity in two wheat cultivars under three irrigation regimes was measured and its relationship to organ N concentration was examined. Based on spectral data of organ powder samples, partial least squares regression (PLSR) models were calibrated to estimate N concentration (Nmass) and validated against laboratory-based measurements. Although spectral reflectance could accurately estimate Nmass, the PLSR-based Nmass-spectra predictive model was found to be organ-specific, organs at the top canopy (chaff and top three leaves) received the best predictions (R2 > 0.88). In addition, N remobilization efficiency (NRE) in the top two leaves and top third internode was highly correlated with its corresponding N concentration change (ΔNmass) with an R2 of 0.90. ΔNmass of the top first internode (TIN1) explained 78% variation of the whole-plant NRE. This study provides a proof of concept for estimating N concentration and assessing N remobilization using hyperspectral data of individual organs, which offers a non-chemical and low-cost approach to screen germplasms for an optimal NRE in drought-resistance breeding.

scholarly journals Field and Growth Chamber Evaluation of Powdery Mildew Disease on Deciduous Azaleas

HortScience ◽  
2010 ◽  
Vol 45 (5) ◽  
pp. 784-789 ◽  
Author(s):  
Michael C. Long ◽  
Stephen L. Krebs ◽  
Stan C. Hokanson
Keyword(s):  
Powdery Mildew ◽  
Field Trial ◽  
Leaf Surface ◽  
Low Cost ◽  
Field Performance ◽  
Resistance Breeding ◽  
Field Resistance ◽  
Growth Chamber ◽  
Leaf Surfaces ◽  
Highly Correlated

Forty-one deciduous azalea (Rhododendron subgen. Pentanthera G. Don) cultivars were assessed for powdery mildew (PM) resistance in a two-location, 3-year field trial. Disease severity (percent leaf area affected) on abaxial leaf surfaces was used to rate the level of field resistance. This measure was proportional to (r = 0.83) but higher than estimates from corresponding adaxial surfaces. Eleven of these cultivars (27%) appeared to be highly resistant under field conditions, i.e., evidence of PM on the leaves was zero or near zero. Twenty-three of the cultivars evaluated in the field experiment were also evaluated in a growth chamber experiment. In contrast to the field study, PM was more severe on the adaxial leaf surface in the growth chamber but still highly correlated with the abaxial response (r = 0.93). Based on adaxial disease scores, no cultivars in the growth chamber experiments were completely resistant. Growth chamber disease ratings based on either leaf surface were predictive of field performance (r2 = 0.62), suggesting use of the chambers could serve as a low-cost, off-season, early selection component of a deciduous azalea PM resistance breeding program.

scholarly journals Organ-specific, multimodal, wireless optoelectronics for high-throughput phenotyping of peripheral neural pathways

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
Woo Seok Kim ◽  
Sungcheol Hong ◽  
Milenka Gamero ◽  
Vivekanand Jeevakumar ◽  
Clay M. Smithhart ◽  
...  
Keyword(s):  
High Throughput ◽  
Low Cost ◽  
Optoelectronic Device ◽  
Antenna System ◽  
Neural Pathways ◽  
Organ Specific ◽  
Coil Antenna ◽  
Sensory Fibers

AbstractThe vagus nerve supports diverse autonomic functions and behaviors important for health and survival. To understand how specific components of the vagus contribute to behaviors and long-term physiological effects, it is critical to modulate their activity with anatomical specificity in awake, freely behaving conditions using reliable methods. Here, we introduce an organ-specific scalable, multimodal, wireless optoelectronic device for precise and chronic optogenetic manipulations in vivo. When combined with an advanced, coil-antenna system and a multiplexing strategy for powering 8 individual homecages using a single RF transmitter, the proposed wireless telemetry enables low cost, high-throughput, and precise functional mapping of peripheral neural circuits, including long-term behavioral and physiological measurements. Deployment of these technologies reveals an unexpected role for stomach, non-stretch vagal sensory fibers in suppressing appetite and demonstrates the durability of the miniature wireless device inside harsh gastric conditions.

scholarly journals Morphological and Chemical Factors Related to Western Flower Thrips Resistance in the Ornamental Gladiolus

Plants ◽  
2021 ◽  
Vol 10 (7) ◽  
pp. 1384
Author(s):  
Dinar S. C. Wahyuni ◽  
Young Hae Choi ◽  
Kirsten A. Leiss ◽  
Peter G. L. Klinkhamer
Keyword(s):  
Host Plant ◽  
Plant Resistance ◽  
Host Plant Resistance ◽  
Frankliniella Occidentalis ◽  
Western Flower Thrips ◽  
Resistance Breeding ◽  
Breeding Programs ◽  
Triterpenoid Saponins ◽  
Flower Thrips ◽  
Highly Correlated

Understanding the mechanisms involved in host plant resistance opens the way for improved resistance breeding programs by using the traits involved as markers. Pest management is a major problem in cultivation of ornamentals. Gladiolus (Gladiolus hybridus L.) is an economically important ornamental in the Netherlands. Gladiolus is especially sensitive to attack by western flower thrips (Frankliniella occidentalis (Pergande) (Thysanoptera:Thripidae)). The objective of this study was, therefore, to investigate morphological and chemical markers for resistance breeding to western flower thrips in Gladiolus varieties. We measured thrips damage of 14 Gladiolus varieties in a whole-plant thrips bioassay and related this to morphological traits with a focus on papillae density. Moreover, we studied chemical host plant resistance to using an eco-metabolomic approach comparing the 1H NMR profiles of thrips resistant and susceptible varieties representing a broad range of papillae densities. Thrips damage varied strongly among varieties: the most susceptible variety showed 130 times more damage than the most resistant one. Varieties with low thrips damage had shorter mesophylls and epidermal cells, as well as a higher density of epicuticular papillae. All three traits related to thrips damage were highly correlated with each other. We observed a number of metabolites related to resistance against thrips: two unidentified triterpenoid saponins and the amino acids alanine and threonine. All these compounds were highly correlated amongst each other as well as to the density of papillae. These correlations suggest that papillae are involved in resistance to thrips by producing and/or storing compounds causing thrips resistance. Although it is not possible to distinguish the individual effects of morphological and chemical traits statistically, our results show that papillae density is an easy marker in Gladiolus-breeding programs targeted at increased resistance to thrips.

scholarly journals Genotype-Dependent Tipburn Severity During Lettuce Hydroponic Culture Is Associated with Altered Nutrient Leaf Content

Agronomy ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 616
Author(s):  
Virginia Birlanga ◽  
José Ramón Acosta-Motos ◽  
José Manuel Pérez-Pérez
Keyword(s):  
Low Cost ◽  
Nutrient Content ◽  
Leafy Vegetables ◽  
Production Methods ◽  
Growing Seasons ◽  
Lactuca Sativa L ◽  
Hydroponic Cultivation ◽  
Highly Correlated ◽  
Nutrient Solutions ◽  
Nutrient Traits

Cultivated lettuce (Lactuca sativa L.) is one of the most important leafy vegetables in the world, and most of the production is concentrated in the Mediterranean Basin. Hydroponics has been successfully utilized for lettuce cultivation, which could contribute to the diversification of production methods and the reduction of water consumption and excessive fertilization. We devised a low-cost procedure for closed hydroponic cultivation and easy phenotyping of root and shoot attributes of lettuce. We studied 12 lettuce genotypes of the crisphead and oak-leaf subtypes, which differed on their tipburn resistance, for three growing seasons (Fall, Winter, and Spring). We found interesting genotype × environment (G × E) interactions for some of the studied traits during early growth. By analyzing tipburn incidence and leaf nutrient content, we were able to identify a number of nutrient traits that were highly correlated with cultivar- and genotype-dependent tipburn. Our experimental setup will allow evaluating different lettuce genotypes in defined nutrient solutions to select for tipburn-tolerant and highly productive genotypes that are suitable for hydroponics.

Vegetation Canopy Coverage Estimation Using Physical Models

2013 ◽  
Vol 726-731 ◽  
pp. 4709-4713
Author(s):  
Lin Jing Zhang ◽  
Hong Zhang Ma ◽  
Zhu Bo Zhou ◽  
Zhong Liang Ren ◽  
Xiao Bo Zhu ◽  
...  
Keyword(s):  
Regression Model ◽  
Simulated Data ◽  
Hyperspectral Data ◽  
Physical Models ◽  
Vegetation Canopy ◽  
Canopy Coverage ◽  
Vegetation Indexes ◽  
Ground Measurement ◽  
Highly Correlated ◽  
Coverage Estimation

Based on the physical models of PROSPECT, SAIL and porosity model, hyperspectral data and canopy coverage data of different combined scenes were simulated. According to the simulated data, we chose four sensitive bands and four sensitive vegetation indexes highly correlated to vegetation canopy coverage, and analyzed the correlation between sensitive bands, sensitive vegetation indexes and canopy coverage. Then we built a regression model of canopy coverage with EVI highly correlated with canopy coverage. At last, we verified this model by experimental data from ground measurement experiment. It shows that there is a high correlation between EVI and canopy coverage and the regression model built by EVI can produce an effective result and the RMSE is less than 0.09.

scholarly journals In vivo total body water assessment by total body electrical conductivity in rats suffering perturbations of water compartment equilibrium

1993 ◽  
Vol 70 (2) ◽  
pp. 433-438 ◽  
Author(s):  
N. Battistini ◽  
F. Virgili ◽  
G. Bedogni ◽  
G. R. Gambella ◽  
A. Bini
Keyword(s):  
Electrical Conductivity ◽  
Total Body Water ◽  
Body Water ◽  
Biliary Cirrhosis ◽  
Least Squares Regression ◽  
Water Compartment ◽  
Invasive Method ◽  
Total Body ◽  
Highly Correlated

Total body electrical conductivity (TOBEC) is a simple and non-invasive method for the assessment of body composition in vivo. Information regarding the applicability of TOBEC in the condition of abnormal fluid balance is scarce. In the present paper we give the results of the comparison between TOBEC and total body water (TBW; assessed by the tritium dilution technique) in three groups of animals: (1) healthy (n 17), (2) expanded fluid volume by secondary biliary cirrhosis (SBC; n 9) and (3) Fiirosemide®-treated rats (n 9). The TOBEC score and TBW by tritium dilution were found to be highly correlated in the pooled sample (r 0·90) and in normal (r 0.·87), SBC (r 0·73) and Furosemide-treated (r 0·89) rats. However, the relationship between TOBEC and TBW, described by least-squares regression analysis, was found to be similar for SBC and normal rats but was significantly different for Furosemide-treated and normal rats. These findings suggest that TOBEC is unable to track TBW accurately when the ratio between intracellular and extracellular water is chronically or acutely altered.

A simple and low-cost method for leaf area measurement of detached leaves

1997 ◽  
Vol 33 (01) ◽  
pp. 65-72 ◽  
Author(s):  
J. T. Korva ◽  
G. A. Forbes
Keyword(s):  
Solanum Tuberosum ◽  
Leaf Area ◽  
Low Cost ◽  
Electronic Equipment ◽  
New Method ◽  
Area Measurement ◽  
Water Spray ◽  
Spray Method ◽  
Detached Leaves ◽  
Highly Correlated

A technique for leaf area measurement utilizing water spray as an inexpensive substitute for electronic equipment was developed and tested with leaves of potato (Solanum tuberosum L.). The leaf areas measured by the spray method were highly correlated with those measured by an electronic area meter. Measurements of leaf area obtained by the spray method were significantly more highly correlated with those obtained by the area meter than were the measurements of dry weights. The main advantages of the new method are precision, accuracy and immediate results at a low cost.

scholarly journals Using Proximal Hyperspectral Sensing to Predict Herbage Nutritive Value for Dairy Farming

Agronomy ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1826
Author(s):  
Federico N. Duranovich ◽  
Ian J. Yule ◽  
Nicolas Lopez-Villalobos ◽  
Nicola M. Shadbolt ◽  
Ina Draganova ◽  
...  
Keyword(s):  
Nutritive Value ◽  
Dairy Farm ◽  
Economic Benefits ◽  
Hyperspectral Data ◽  
Metabolizable Energy ◽  
Neutral Detergent Fiber ◽  
Canopy Reflectance ◽  
Least Squares Regression ◽  
Proximal Sensing ◽  
Digestible Organic Matter

This study focuses on calibrating and validating models for hyperspectral canopy reflectance data that are useful to predict the nutritive value of ryegrass-white clover mixed herbage available to the grazing cow. Hyperspectral measurements and herbage cuts were collected from 286 sampling plots from a dairy farm from July 2017 to May 2018. Hyperspectral data were pre-treated by applying a Savitzky-Golay filter followed by a Gap-segment derivative algorithm. Herbage samples were analyzed for determination of herbage nutritive value traits, digestible organic matter in dry matter (DOMD), metabolizable energy (ME), crude protein (CP), neutral detergent fiber (NDF) and acid detergent fiber (ADF). Partial least squares regression was performed to calibrate the spectra against the five nutritive value traits. Results indicate that accuracy was moderately high for the CP model (R2 = 0.78) and moderate for the DOMD, ME, NDF and ADF models (0.54 < R2 < 0.67). The possibility of being able to use proximal sensing for the estimation of herbage nutritive value in the field could potentially contribute to more efficient grazing management with potential economic benefits for the farm business.

scholarly journals Mapping the Bathymetry of Melt Ponds on Arctic Sea Ice Using Hyperspectral Imagery

2020 ◽  
Vol 12 (16) ◽  
pp. 2623 ◽  
Author(s):  
Marcel König ◽  
Gerit Birnbaum ◽  
Natascha Oppelt
Keyword(s):  
Sea Ice ◽  
Hyperspectral Imagery ◽  
Atmospheric Correction ◽  
Hyperspectral Data ◽  
Arctic Sea Ice ◽  
Atmospheric Conditions ◽  
Melt Pond ◽  
Melt Ponds ◽  
Arctic Sea ◽  
Highly Correlated

Hyperspectral remote-sensing instruments on unmanned aerial vehicles (UAVs), aircraft and satellites offer new opportunities for sea ice observations. We present the first study using airborne hyperspectral imagery of Arctic sea ice and evaluate two atmospheric correction approaches (ATCOR-4 (Atmospheric and Topographic Correction version 4; v7.0.0) and empirical line calibration). We apply an existing, field data-based model to derive the depth of melt ponds, to airborne hyperspectral AisaEAGLE imagery and validate results with in situ measurements. ATCOR-4 results roughly match the shape of field spectra but overestimate reflectance resulting in high root-mean-square error (RMSE) (between 0.08 and 0.16). Noisy reflectance spectra may be attributed to the low flight altitude of 200 ft and Arctic atmospheric conditions. Empirical line calibration resulted in smooth, accurate spectra (RMSE < 0.05) that enabled the assessment of melt pond bathymetry. Measured and modeled pond bathymetry are highly correlated (r = 0.86) and accurate (RMSE = 4.04 cm), and the model explains a large portion of the variability (R2 = 0.74). We conclude that an accurate assessment of melt pond bathymetry using airborne hyperspectral data is possible subject to accurate atmospheric correction. Furthermore, we see the necessity to improve existing approaches with Arctic-specific atmospheric profiles and aerosol models and/or by using multiple reference targets on the ground.

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