オオムギ白渋病菌の侵入菌糸及び吸器と寄主細胞との関係に就いての観察

This paper deals with the results of inoculation experiments, in which the excised first leaves of barley seedlings were inoculated with conidia of race 1 of Erysiphe graminis hordei, the basal parts of the leaves being inserted in water or 0.01-0.015mol solutions of certain inorganic salts.<BR>1. When the leaves are inserted in water, the first haustorium of the mildew colony is formed more easily in the auxiliary cell than in the ordinary epidermal cell. Frequency of the initial infection of auxiliary-cell by the first haustorium may attain as high as 90 per cent of the total infections.<BR>2. The liability of the auxiliary-cell to initial infection seems to be not necessarily connected with movement of the stoma, nor with the thickness of the outer wall or the sunken position of the auxiliary cell.<BR>3. Solutions of calcium salts increased remarkably mildew susceptibility of the leaves. It is worthly to mention that the initial infections of ordinary epidernal cells increase notably in number, hence the frequency ratio of the auxiliary-cell-infection by the first haustorium falls. At higher concentrations (0.04 or 0.07mol) of calcium salts, the effect was more conspicuous.<BR>4. Similar effects by calcium salts were observed when conidia of a different race (IX) and of the Agropyron mildew were used as inocula.<BR>5. Magnesium chloride increased susceptibility, but less than calcium salts, while barium chloride decreased it. Potassium and soda salts exerted no marked influence upon susceptibility, while lithium chloride furnished with remarkable rsistance. Ammonium salts increased resistance in some instances.<BR>6. Mixed solutions of calcium salts with potassium or soda salts caused intermediate influence upon susceptibility. Lithium chloride has a strong antagonistic action to calcium salts.<BR>7. Darkening the leaves or washing them with running water showed similar, but less effects with calcium salts.