A laboratory procedure for determining relative levels of field resistance in soybeans to Phytophthora megasperma f.sp. Glycinea

1982 ◽  
Vol 33 (1) ◽  
pp. 33 ◽  
Author(s):  
JAG Irwin ◽  
PW Langdon
Keyword(s):  
Rapid Determination ◽  
Dry Weight ◽  
Field Resistance ◽  
Inoculum Level ◽  
Laboratory Procedure ◽  
Phytophthora Megasperma ◽  
Breeding Programs ◽  
Made In ◽  
Laboratory Assay

A reliable laboratory assay is described which allows rapid determination of relative levels of field resistance in soybeans to Phytophthora megasperma fsp, glycinea. The expression of field resistance depended on both the inoculum level and the age of seedlings at time of saturation of the potting mix with water. At inoculum levels in the range 0.018-0.576 g dry weight of mycelium per kg dry weight of potting mix, ready differentiation in the resistance levels of the cultivars Davis (field resistant) and Semstar (field susceptible) could be made after 7 days of continuous saturation of the mix, which commenced 3 days after sowing. When inoculated by the conventional hypocotyl puncture technique, both cultivars gave susceptible reactions. The seedling assay was used to screen a range of soybean cultivars with known levels of field resistance to the fungus. Disease assessments made in the laboratory assay were similar to those expected under natural conditions of infection in the field. Possible use of the method in future soybean breeding programs is discussed.

scholarly journals Determination of trace elements in the plants of Mt. Bozdag, Izmir, Turkey

2010 ◽  
Vol 62 (3) ◽  
pp. 731-738 ◽  
Author(s):  
D. Yildiz ◽  
I. Kula ◽  
G. Ay ◽  
S. Baslar ◽  
Y. Dogan
Keyword(s):  
Trace Elements ◽  
Woody Plants ◽  
Statistical Significance ◽  
Absorption Spectrometry ◽  
Dry Weight ◽  
Current Level ◽  
The Mean ◽  
Herbaceous And Woody Plants ◽  
Made In

The aim of this study was to determine the current level of atmospheric heavy metal content on the Bozdag Mountain of the Aegean Region, Turkey. Twenty nine different plants were selected to study their potential as biomonitors of trace elements such as Ni, Zn, Fe, Pb, Mn and Cd (?g g-1, dry weight). The samples were collected from two different altitudes of Mt. Bozdag. The concentrations of trace elements were determined by atomic absorption spectrometry. The mean concentrations determined at 1000 m altitude ranged from 0.025 to 1.609, 0.232 to 0.731, 0.578 to 5.983, 0.287 to 0.565 and 0.176 to 2.659 (?g g-1, dry weight), for Ni, Zn, Fe, Pb and Mn, respectively. At the altitude of 1600 m, the values ranged from 0.023 to 0.939, 0.258 to 1.254, 0.839 to 5.176, 0.301 to 1.341 and 0.405 to 3.351 (?g g-1, dry weight) for Ni, Zn, Fe, Pb and Mn, respectively. No Cd was detected at either altitude. Statistical significance was determined by the independent sample t-test and comparisons were made in order to determine if there were any differences between the averages of herbaceous and woody plants. .

scholarly journals Determination and Metabolite Profiling of Mixtures of Triterpenoid Saponins from Seeds of Chilean Quinoa (Chenopodium quinoa) Germplasm

Agronomy ◽  
2021 ◽  
Vol 11 (9) ◽  
pp. 1867
Author(s):  
Archis Pandya ◽  
Björn Thiele ◽  
Andres Zurita-Silva ◽  
Björn Usadel ◽  
Fabio Fiorani
Keyword(s):  
Chenopodium Quinoa ◽  
Dry Weight ◽  
Organoleptic Properties ◽  
Breeding Programs ◽  
Triterpenoid Saponins ◽  
Mass Estimation ◽  
Fticr Ms ◽  
Genotype Effect ◽  
Saponin Content

The seed pericarp of Chenopodium quinoa Willd. (quinoa) contains a mixture of triterpenoid saponins conferring undesired organoleptic properties. In this study, we evaluated saponin content and their corresponding sapogenins in 114 different quinoa accessions. Relative saponin content ranged from 0.22 to 15.04 mg/g of seed dry weight among the genotypes studied and the genotype effect was significant (p < 0.001). About 75% of the genotypes could be classified as low-saponin content lines which is promising in view of ongoing plant breeding efforts. In addition to the quantitative determination of saponins, metabolic profiling was performed by LC-FTICR-MS and LC-MS/MS. We obtained highly accurate mass estimation from ion spectra allowing the identification of twelve saponins of the oleanane type. These differ in their aglycons and in the number and type of glycoside units. Interestingly, we identified a saponin compound that, to our knowledge, had not been reported previously. Our study highlights that there is considerable variability concerning saponin content in quinoa, which contributes to the valorization of genetic resources towards the identification of genotypes that could be utilized in current and future quinoa breeding programs.

scholarly journals Rapid Determination of Nitrogen Status in Pansy

HortScience ◽  
2003 ◽  
Vol 38 (4) ◽  
pp. 537-541 ◽  
Author(s):  
James E. Altland ◽  
Charles H. Gilliam ◽  
Gary J. Keever ◽  
James H. Edwards ◽  
Jeff L. Sibley ◽  
...  
Keyword(s):  
Nitrate Concentration ◽  
Rapid Determination ◽  
Dry Weight ◽  
Foliar Nitrogen ◽  
N Deficiency ◽  
Highly Correlated ◽  
The Relationship ◽  
Spad Readings ◽  
N Status

Two experiments were conducted with pansy (Viola ×wittrockiana Gams `Bingo Yello') to determine the relationship between foliar nitrogen (% of dry weight) (FN) and either sap nitrate concentration (SN) in petioles or SPAD readings of foliage. FN was highly correlated to SN throughout both experiments (r = 0.80 to 0.91). FN was poorly correlated to SPAD readings early in both experiments (r = 0.54 to 0.65), but more highly correlated later when visual symptoms of N deficiency were apparent (r = 0.84 to 0.90). SN determined with the Cardy sap nitrate meter was a reliable predictor of FN in pansy, while SPAD readings were only reliable after symptoms of N deficiency were visually evident. FN can be predicted with SN using the following equation: log(SN) = 0.47*FN + 1.6 [r2 = 0.80, n = 132]. Growers and landscape professionals can use SN readings to predict FN levels in pansy, and thus rapidly and accurately diagnose the N status of their crop.

Microwave‐oven drying of rice leaves for rapid determination of dry weight and nitrogen concentration

1994 ◽  
Vol 17 (1) ◽  
pp. 209-217 ◽  
Author(s):  
Shaobing Peng ◽  
Ma. Rebecca C. Laza ◽  
Felipe V. Garcia ◽  
Kenneth G. Cassman
Keyword(s):  
Rapid Determination ◽  
Nitrogen Concentration ◽  
Dry Weight ◽  
Microwave Oven ◽  
Oven Drying ◽  
Rice Leaves

scholarly journals Rapid Determination of Nitrogen Status in Annual Vinca

2002 ◽  
Vol 20 (3) ◽  
pp. 189-194 ◽  
Author(s):  
James E. Altland ◽  
Charles H. Gilliam ◽  
James H. Edwards ◽  
Gary J. Keever ◽  
Donna C. Fare ◽  
...  
Keyword(s):  
Rapid Determination ◽  
Correlation Coefficients ◽  
Growth Index ◽  
Dry Weight ◽  
Total N ◽  
The Relationship ◽  
Petiole Sap ◽  
Spad Readings ◽  
N Status

Abstract Three experiments were conducted to develop a method for rapid determination of nitrogen (N) status in ‘Pacifica White’ vinca (Catharanthus roseus (L.) G. Don). In experiment 1, N was applied to potted vinca at 40, 80, 120, or 160 ppm N to produce plants ranging from N deficient to N sufficient. Data were collected 14, 28, and 42 days after treatment (DAT) and included flower number, growth index [(height + width + width) ÷ 3], and from recently matured foliage the following parameters: SPAD-502 readings, petiole sap nitrate (SN) concentration, and total-N (percent of dry weight) (FN). Experiment 2 was similar with the exception that N rates applied were 30, 60, 90, 120, 150, or 180 ppm N, and data were collected 14, 29, and 42 DAT. In experiment 3, N was applied at 0, 90, or 180 ppm N and data were collected 0, 4, 7, 10, and 14 DAT. In experiments 1 and 2, SPAD readings were poorly correlated to FN (correlation coefficients ranged from 0.35 to 0.88) and the relationship between FN and SPAD readings changed at different collection dates. Petiole sap nitrate concentration determined by a Cardy nitrate meter was highly correlated throughout the three experiments. Above 380 ppm SN, the relationship between FN and SN was determined to be: SN/1000 = 2.3 × FN-4.8 (r2 = 0.73, n = 104). In experiment 3, FN and SN readings were able to detect N deficiency in vinca by 4 DAT, despite lack of visual symptoms until 14 DAT. SPAD readings were not suitable for predicting FN and plant N status. SN was a reliable predictor of FN and thus could be used to rapidly determine plant N status.

Weak Beam Imaging and Diffraction Studies of Stacking Faults in Silicon

1976 ◽  
Vol 34 ◽  
pp. 590-591
Author(s):  
T. Y. Tan ◽  
W. K. Tice
Keyword(s):  
Fast Neutron ◽  
Rapid Determination ◽  
Stacking Faults ◽  
Imaging Method ◽  
Large Reduction ◽  
Dislocation Loops ◽  
Fringe Spacing ◽  
Weak Beam ◽  
Kinematical Theory

In studying ion implanted semiconductors and fast neutron irradiated metals, the need for characterizing small dislocation loops having diameters of a few hundred angstrom units usually arises. The weak beam imaging method is a powerful technique for analyzing these loops. Because of the large reduction in stacking fault (SF) fringe spacing at large sg, this method allows for a rapid determination of whether the loop is faulted, and, hence, whether it is a perfect or a Frank partial loop. This method was first used by Bicknell to image small faulted loops in boron implanted silicon. He explained the fringe spacing by kinematical theory, i.e., ≃l/(Sg) in the fault fringe in depth oscillation. The fault image contrast formation mechanism is, however, really more complicated.

The quantitative comparison of experimental and simulated diffraction contrast images

1995 ◽  
Vol 53 ◽  
pp. 102-103
Author(s):  
Stuart McKernan
Keyword(s):  
Image Processing ◽  
Personal Computer ◽  
Close Agreement ◽  
Quantitative Comparison ◽  
Image Simulation ◽  
Computing Power ◽  
Diffraction Contrast ◽  
Simulated Images ◽  
Made In

For many years the concept of quantitative diffraction contrast experiments might have consisted of the determination of dislocation Burgers vectors using a g.b = 0 criterion from several different 2-beam images. Since the advent of the personal computer revolution, the available computing power for performing image-processing and image-simulation calculations is enormous and ubiquitous. Several programs now exist to perform simulations of diffraction contrast images using various approximations. The most common approximations are the use of only 2-beams or a single systematic row to calculate the image contrast, or calculating the image using a column approximation. The increasing amount of literature showing comparisons of experimental and simulated images shows that it is possible to obtain very close agreement between the two images; although the choice of parameters used, and the assumptions made, in performing the calculation must be properly dealt with. The simulation of the images of defects in materials has, in many cases, therefore become a tractable problem.

Methods for rapid determination of pecan (Carya illinoensis) seed viability

2017 ◽  
Vol 45 (2) ◽  
pp. 455-464
Author(s):  
T.T. Xue ◽  
J. Liu ◽  
Y.B. Shen ◽  
G.Q. Liu
Keyword(s):  
Rapid Determination ◽  
Seed Viability ◽  
Carya Illinoensis
Sign in / Sign up

Export Citation Format

Share Document