STUDIES ON THE NATURE OF RUST RESISTANCE IN WHEAT

1929 ◽  
Vol 1 (1) ◽  
pp. 5-35 ◽  
Author(s):  
R. Newton ◽  
J. V. Lehmann ◽  
A. E. Clarke

A program of investigations is outlined and the results of the first three years' work reported. Eight wheat varieties, differing widely in resistance to stem rust, showed no corresponding differences in the physico-chemical properties of their expressed tissue-fluids. The infection of susceptible varieties was in some cases reduced by administering extracts of resistant varieties in petri-dish cultures or by direct injection into inoculated leaves. The injection of the juice of infected leaves into healthy leaves failed to demonstrate the presence of any toxin excreted by the fungus. The injection of salicylic acid, catechol or vanillin in suitable concentrations frequently caused a reduction in infection. These phenolic compounds in very low concentrations stimulated the growth of Helminthosporium sativum, but at higher concentrations inhibited it. The same phenols inhibited the germination of rust spores. On filtered wheat-juice rust spores also failed to germinate, though on unfiltered juice they germinated normally.

2014 ◽  
Vol 11 (96) ◽  
pp. 20130931 ◽  
Author(s):  
Christian Pfeiffer ◽  
Christoph Rehbock ◽  
Dominik Hühn ◽  
Carolina Carrillo-Carrion ◽  
Dorleta Jimenez de Aberasturi ◽  
...  

The physico-chemical properties of colloidal nanoparticles (NPs) are influenced by their local environment, as, in turn, the local environment influences the physico-chemical properties of the NPs. In other words, the local environment around NPs has a profound impact on the NPs, and it is different from bulk due to interaction with the NP surface. So far, this important effect has not been addressed in a comprehensive way in the literature. The vicinity of NPs can be sensitively influenced by local ions and ligands, with effects already occurring at extremely low concentrations. NPs in the Hückel regime are more sensitive to fluctuations in the ionic environment, because of a larger Debye length. The local ion concentration hereby affects the colloidal stability of the NPs, as it is different from bulk owing to Debye Hückel screening caused by the charge of the NPs. This can have subtle effects, now caused by the environment to the performance of the NP, such as for example a buffering effect caused by surface reaction on ultrapure ligand-free nanogold, a size quenching effect in the presence of specific ions and a significant impact on fluorophore-labelled NPs acting as ion sensors. Thus, the aim of this review is to clarify and give an unifying view of the complex interplay between the NP's surface with their nanoenvironment.


2021 ◽  
Vol 14 (4) ◽  
pp. 570-581
Author(s):  
Vasily N. Romanov ◽  
◽  
Natalia S. Kozulina ◽  
Tatiana A. Snitkova ◽  
Albina V. Vasilenko ◽  
...  

A method for producing granular fertilizers based on pine sawdust containing ammonium nitrate is proposed. Physico-chemical properties of sawdust and fertilizers containing 20.0 wt.% nitrogen were studied. The effect of pretreatment of pine sawdust with 1 % wt. with a water solution of NaOH on the properties of granular fertilizers was explored. The results of a field trial on the cultivation of wheat varieties «Krasnoyarskaya 12» revealed the growth-stimulating effect of nitrogen-containing granular fertilizers in comparison with an unfertilized background. A more effective influenceon wheat yield of granular fertilizer fabricated from pine sawdust after their treatment with 1 % wt. with a water solution of NaOHThe achieved effect on 1,9 c/ha higher in comparison with thefertilizer based on original sawdust


2016 ◽  
Vol 52 (No. 4) ◽  
pp. 242-249 ◽  
Author(s):  
Li Tian-ya ◽  
Wu Xian-xin ◽  
Xu Xiao-feng ◽  
Wang Wan-lin ◽  
Cao Yuan-yin

To determine stem rust resistance genes of wheat varieties in Yunnan province, 11 Chinese strains of Puccinia graminis f.sp. tritici with different virulence and 1 artificial mutant strain were used in 110 wheat varieties. The results indicated that among the 45 Sr genes, Sr31, Sr5, SrTmp, Sr30, Sr36, Sr8a, Sr11, Sr24, Sr29, Sr34, Sr9e, Sr26, Sr38, Sr47, and SrTt3 were characterised in 55 wheat varieties singly or in combination. Sr5, Sr31, SrTmp, Sr36, and Sr30 were contained in 17, 16, 5, 5, and 3 cultivars, respectively. Six cultivars contained Sr24 and/or Sr34. Three plant materials likely contained one or more of Sr8a, Sr11, Sr34, and Sr23 genes as well as other unknown genes. The 16 immune or highly resistant varieties contained one or more of Sr9e, Sr26, Sr38, Sr47, SrTt3, and other unknown resistance genes. The reaction types on 22 of the tested cultivars were different from those on Sr genes tested, and their resistance genes could not be analysed. Additionally, 17 varieties were susceptible to all the tested strains, having no postulation value. Our study provides a basis for improved breeding of stem rust resistant wheat in China.


2020 ◽  
Vol 63 (1) ◽  
pp. 1-8
Author(s):  
Ayesha Riaz ◽  
Imran Pasha ◽  
Mian Kamran Sharif

In this study, we investigated various physico-chemical properties of wheat and evaluated their correlation with cookie attributes. Results showed that damaged starch in wheat varieties ranged from 6.28 to 10.97%. SDS-sed. and AWRC values were recorded as 18.20-30.50 mL and 43.91-66.85%, respectively. WSRC, SOCSRC, SUCSRC and LASRC values varied over a wide range as 50.83-69.64%, 56.66-82.03%, 75.79-106.97% and 79.43-121.20%, respectively. Physical analyses of cookies made with wheat varieties indicated 25.20-26.60 cm width, 5.80-6.40 cm thickness and 39.38-45.86 spread factor and 2.17-3.91 kg hardness. Important correlations were reported between water absorption and SDS sedimentation (r= 0.912*). Likewise, a positive relationship was found between damaged starch and SUCSRC (r=  0.985**).Spread factor was found to be negatively correlated to ash (r= -0.977**), protein(r= -0.892*), SOCSRC (r= -0.952*), WSRC (r= -0.892*) and hardness (r= -0.990**).Correlation studies indicated that physico-chemical characteristics of flour are imperative in the evaluation of cookie making quality.


Author(s):  
H. Gross ◽  
H. Moor

Fracturing under ultrahigh vacuum (UHV, p ≤ 10-9 Torr) produces membrane fracture faces devoid of contamination. Such clean surfaces are a prerequisite foe studies of interactions between condensing molecules is possible and surface forces are unequally distributed, the condensate will accumulate at places with high binding forces; crystallites will arise which may be useful a probes for surface sites with specific physico-chemical properties. Specific “decoration” with crystallites can be achieved nby exposing membrane fracture faces to water vopour. A device was developed which enables the production of pure water vapour and the controlled variation of its partial pressure in an UHV freeze-fracture apparatus (Fig.1a). Under vaccum (≤ 10-3 Torr), small container filled with copper-sulfate-pentahydrate is heated with a heating coil, with the temperature controlled by means of a thermocouple. The water of hydration thereby released enters a storage vessel.


1990 ◽  
Vol 63 (03) ◽  
pp. 499-504 ◽  
Author(s):  
A Electricwala ◽  
L Irons ◽  
R Wait ◽  
R J G Carr ◽  
R J Ling ◽  
...  

SummaryPhysico-chemical properties of recombinant desulphatohirudin expressed in yeast (CIBA GEIGY code No. CGP 39393) were reinvestigated. As previously reported for natural hirudin, the recombinant molecule exhibited abnormal behaviour by gel filtration with an apparent molecular weight greater than that based on the primary structure. However, molecular weight estimation by SDS gel electrophoresis, FAB-mass spectrometry and Photon Correlation Spectroscopy were in agreement with the theoretical molecular weight, with little suggestion of dimer or aggregate formation. Circular dichroism studies of the recombinant molecule show similar spectra at different pH values but are markedly different from that reported by Konno et al. (13) for a natural hirudin-variant. Our CD studies indicate the presence of about 60% beta sheet and the absence of alpha helix in the secondary structure of recombinant hirudin, in agreement with the conformation determined by NMR studies (17)


1963 ◽  
Vol 79 (2) ◽  
pp. 263-293 ◽  
Author(s):  
E.M. Savitskii ◽  
V.F. Terekhova ◽  
O.P. Naumkin

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