EFFECT OF BENZIMIDAZOLE, DIMETHYLBENZIMIDAZOLE, GLUCOSE, AND METAL IONS ON THE DEVELOPMENT OF PUCCINIA GRAMINIS TRITICI ON DETACHED LEAVES OF KHAPLI WHEAT

1959 ◽  
Vol 37 (2) ◽  
pp. 239-244 ◽  
Author(s):  
Dalton Wang

Leaves of Khapli wheat which are normally resistant to race 15B-1 of Puccinia graminis tritici become susceptible when detached and floated on water. This breakdown of resistance can be reversed by floating the detached leaves on a solution of benzimidazole. The effect of benzimidazole, however, can be nullified by a supply of exogenous glucose or 5,6-dimethylbenzimidazole. Furthermore, the resistance can again be restored by the presence of cobalt ion combined in solution with glucose and benzimidazole or with glucose and 5,6-dimethylbenzimidazole. Cobalt ions alone, or in combination with glucose, or with benzimidazole, or with 5,6-dimethylbenzimidazole separately have no effect on rust development. In contrast, nickel ion alone or in any combination has a profound inhibitory effect on the development of rust in detached leaves. Other chemicals were also included in this study, and their effect on rust development is discussed. It is speculated that benzimidazole or a derivative of it and cobalt may form a vitamin B12-like factor which is required by the host to maintain its normal metabolic activities.

1964 ◽  
Vol 42 (2) ◽  
pp. 139-144 ◽  
Author(s):  
Michael Shaw ◽  
B. I. Sahai Srivastava

The purines were precipitated from alcohol extracts of Little Club wheat with copper oxide or absorbed from perchloric acid extracts with Norit A. Guanine, adenine, and an unidentified purine were isolated from seedlings germinated in darkness and from the tops of young plants grown in the greenhouse. Adenine and the unidentified purine were present in much larger amounts than guanine. The concentrations of adenine and the unidentified purine in the first seedling leaves were increased approximately four- and five-fold by infection with Puccinia graminis tritici Erikss. and Henn. No evidence was obtained for the presence of any purine or purine-like substance in uninfected or infected leaves which would delay senescence in detached leaves as do kinetin, benzimidazole, and purine-like substances present in coconut endosperm.


2019 ◽  
Vol 9 (2) ◽  
pp. 151-162
Author(s):  
Shveta Acharya ◽  
Arun Kumar Sharma

Background: The metal ions play a vital role in a large number of widely differing biological processes. Some of these processes are quite specific in their metal ion requirements. In that only certain metal ions, in specific oxidation states, can full fill the necessary catalytic or structural requirement, while other processes are much less specific. Objective: In this paper we report the binding of Mn (II), Ni (II) and Co (II) with albumin are reported employing spectrophotometric and pH metric method. In order to distinguish between ionic and colloidal linking, the binding of metal by using pH metric and viscometric methods and the result are discussed in terms of electrovalent and coordinate bonding. Methods: The binding of Ni+2, Co+2 and Mn+2 ions have been studied with egg protein at different pH values and temperatures by the spectrometric technique. Results: The binding data were found to be pH and temperature dependent. The intrinsic association constants (k) and the number of binding sites (n) were calculated from Scatchard plots and found to be at the maximum at lower pH and at lower temperatures. Therefore, a lower temperature and lower pH offered more sites in the protein molecule for interaction with these metal ions. Statistical effects seem to be more significant at lower Ni+2, Co+2 and Mn+2 ions concentrations, while at higher concentrations electrostatic effects and heterogeneity of sites are more significant. Conclusion: The pH metric as well as viscometric data provided sufficient evidence about the linking of cobalt, nickel and manganese ions with the nitrogen groups of albumin. From the nature and height of curves in the three cases it may be concluded that nickel ions bound strongly while the cobalt ions bound weakly.


2012 ◽  
Vol 13 (1) ◽  
pp. 31 ◽  
Author(s):  
Subrahmaniam Nagarajan ◽  
Hans J. Kogel ◽  
Jan C. Zadoks

Dispersal of a new virulence of Puccinia graminis tritici (Pgt)-Ug99 from Uganda-Kenya to Yemen, over >1000 km, happened in four years. Geo-agro-ecology of wheat cultivation and the epidemiology of Pgt indicate that the Rift Valley is a natural conduit “flyway.” The widely prevalent “green bridges” favor survival and spread of Pgt. This part of the Rift Valley is one single epidemiological zone, and the annual Pgt build-up is from the endogenous inoculum. Accepted for publication 18 October 2012. Published 14 November 2012.


Nature ◽  
1945 ◽  
Vol 155 (3929) ◽  
pp. 205-205
Author(s):  
I. A. WATSON ◽  
W. L. WATERHOUSE

1934 ◽  
Vol 11 (6) ◽  
pp. 667-686 ◽  
Author(s):  
J. Ansel Anderson

Urediniospores of Puccinia graminis tritici, form 21, were sown on buffer solutions covering the range from pH 3 to pH 8. Maximum germination was obtained between pH 5.8 and 6.5, with indications that if the point of maximum germination could be determined with precision it would be found to lie in the neighborhood of pH 6.2.The effect of buffered and unbuffered solutions of pure phenolic compounds on the germination of urediniospores was studied. Greater inhibition was obtained with unbuffered solutions owing to the additional effect of hydrogen ion concentration. In buffered solutions, at pH 6.0, germination was prevented by 45 p.p.m. of hydroquinone, 125 of o-cresol, 180 of anisic acid, 250 of benzoic acid, 340 of catechol, 400 of guaiacol and 600 of phenol. A number of other compounds were also studied. The inhibitory effects of compounds, of which the bactericidal effects are known, are fairly closely related to their bactericidal efficiency.Investigations were made of the inhibitory effects on spore germination and the growth of germ tubes, of aqueous dilutions of 15, 10, 5 and 2.5% of the press-juice of Vernal, Khapli, Marquis and Little Club wheats. Statistical treatment of the data accumulated in ten series of determinations, in which a total of 160,000 spores was counted, showed that significant differences occurred between varieties and that variations in the total solid content and hydrogen ion concentration of the press-juice had no consistent effect upon the results. Although the results were not entirely clear-cut, it is concluded that the varieties fall in the following order with respect to increasing inhibitory effect of their extracts: Vernal, Marquis, Khapli and Little Club. Since Vernal and Khapli are resistant to form 21 whereas Marquis and Little Club are susceptible, the results fail to show any relationship between the effects of host extracts on the germination of urediniospores, or on the growth of germ tubes, and the rust resistance of the variety.


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