Three poplar clones, Populus deltoides angulata (resistant), P. deltoides missouriensis (susceptible), and P. “Kamabuchi-1” (variable in susceptibility according to the growing season) were inoculated with uredospores of Melampsora larici-populina, incubated for 9 days, and then cuttings from healthy and infected plants were fed with 14CO2 for 20 hours.In healthy and rusted leaves of these clones, at least six kinds of sugars, sucrose, glucose, fructose, raffinose (?) and two other unidentified sugars, were detected on the autoradio-chromatograms. The specific radioactivity of each sugar generally increased in rusted leaves with a few exceptions, whereas there were remarkable differences in the increasing degree of specific radioactivity among sugar fractions.Labeling of sucrose, glucose and fructose with 14C from 14CO2 increased by rust infection, and the degree of the increase was conspicuous in P. deltoides missouriensis, while it was insignificant in P. deltoides angulata. A general increase in both total and specific radio-activity of sucrose may suggest the possibility of stimulated photosynthesis in rusted leaves.The degree of increase in the specific radioactivity of glucose and fructose were almost equal in rusted leaves of P. deltoides angulata, whereas particular increases were observed for glucose in P. deltoides missouriensis and for fructose in P. “Kamabuchi”, respectively. This fact would suggest that in rusted leaves of the latter two clones the disturbance of carbohydrate metabolism incited by rust infection is still continued, and that there are considerable differences between two clones concerning the pathway of carbohydrate metabolism in infected leaves.

Carbohydrate Metabolism

Rust (programming language)

10.3186/jjphytopath.32.34

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Citations (1)

Species and formae speciales of Fusaria causing damping-off and root-rot of coniferous seedlings in Japan

Japanese Journal of Phytopathology (1966)

Takken Matuo O. Chiba

Damping-off of coniferous seedlings, especially the root-rot type of the disease, is mostly caused by several species of Fusarium. The results of idenification of 106 isolates from diseased roots of nursery stocks at various localities in Japan, including 12 isolates from deciduous trees, showed that about 88 per cent of isolates were F. oxysporum and the rest of them were composed of F. solani, F. roseum, and F. lateritium. From these isolates 13 were selected owing to their higher pathogenicity to coniferous seedlings and were examined for their formae speciales by a series of inoculation experiments. It was made clear that all isolates of F. oxysporum were capable of infecting seedlings of Pinus densiflora, Larix leptolepis, Cryptomeria japonica, and Chamaecyparis obtusa, while they were non-pathogenic to any kinds of indicator plants of the other formae speciales of this species. Moreover, the tests also indicated that a possible difference in virulence existed among the isolates; six of tested isolates were most virulent to L. leptolepis and the rest one was more pathogenic to C. japonica and C. obtusa than L. leptolepis. It may be concluded from these results that the former six isolates are classified as F. oxysporum f. sp. pini race 1 and the remaining one as race 2, respectively.Two isolates of F. solani were identified as F. solani f. sp. radicicola, which frequently showed variable pathogenicity. There found certain differences in the pathogenicity between the isolates of F. roseum and F. roseum f. sp. cerealis, and also between the isolates of F. lateritium and F. lateritium f. sp. mori as well as f. sp. cerealis, but it was difficult, from their variable pathogenicty, to classified them as new formae speciales of these species.In general, the occurrence of damping-off of coniferous seedlings depends remarkably upon the environmental factors and it seems that many kinds of Fusaria would be able to become causal agents of the disease under favorable environmental conditions for disease development.

Cryptomeria

Root rot

Chamaecyparis

Fusarium solani

Pinus densiflora

10.3186/jjphytopath.32.14

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Citations (6)

NATURE OF RESISTANCE OF POPLAR CLONES TO A LEAF RUST, MELAMPSORA LARICI-POPULINA KLEB

Elsevier eBooks (1966)

O. Chiba

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