Although soil-borne cereal mosaics do not develop in plants grown in the virus-infested soils treated with some chemicals or in the soil heated at 50-60°C for 10 minutes, it is believed commonly that the only practical method of control is by planting resistant varieties. However, according to the variety tests of barley sown in the soil infested with barley yellow mosaic virus (BYMV), which have been conducted by the present writer making use of about 90 varieties, most varieties including so-called resistant or immune varieties often show to be susceptible. In these tests, moreover, the differences of environmental conditions exerted effects on the infection and expression of symptoms. It is necessary, therefore, that the recommended varieties are decided for each region. Previously, the writer designed and manufactured a flame-projector for soil sterilization, by way of trial, which was able to heat the soil within the depth of 15cm at 40-60°C for several minutes. Treatment by this equipment was conducted practically on a BYMV-infested farmer's field by heating soils near sowing lines just before planting seeds. This treatment needed only to spend 30-40 liter per 10 are of kerosene, and was very effective for control of the disease and also of manganese deficiency.
Furthermore, an attempt has been made to find out a more practical method of controlling of soil-borne cereal mosaic diseases in Japan, and following results have been obtained.
(1) Pyroligneous acid (wood vinegar) controlled soil-borne cereal mosaics when the virus-infested soils were drenched with the original liquid or diluted ones at several days before planting seeds.
(2) Throughout all the experiments, namely: tests in glasshouses or in the field and also experiments using both the soils infested respectively with wheat yellow mosaic virus (WYMV, Marmor tritici var. fulvum McK.) and BYMV, pyroligneous acid showed to be very effective in controlling the diseases. The pH values of soils treated with diluted liquids of pyroligneous acid went back to the original pH within several days after drenching.
(3) Drenching with liquids of pyroligneous acid diluted 1:4 to 1:8 with water were not only effective on the diseases but were stimulative for the growth of wheat and barley plants. Moreover, these soil treatments suppressed the growth of weeds.
(4) Liquids of acetic acid which were prepared from glacial acetic acid and adjusted at the same pH values as ones of pyroligneous acid tested, showed no remarkable effects on the diseases such as shown by pyroligneous acid in glasshouse tests.
(5) The original liquid of pyroligneous acid contains 2-2.8 percent of formaldehyde. It is well known that formaldehyde show sterilizing effects considerably on the soils infested with several kinds of soil-borne plant viruses. It seems, therefore, that the effects of pyroligneous acid on soil-borne cereal mosaics are not only caused by its acidity but rather attributable to sterilizing effects of formaldehyde and of other similar substances including in pyroligneous acid.
(6) Most Japanese farmers in mountainous areas have a custom of charcoal-making, and they can collect pyroligneous acid easily as a by-product of charcoal-making. So the controlling method of soil-borne cereal mosaics by pyroligneous acid seems to be of practical use in Japan.

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For the purpose of researching differences in nucleotides between healthy and dwarf diseased rice plants, ribonucleic acid (RNA) was prepared from rice plant leaves by a modified Kirby's method. Nucleotides were then obtained from the RNA by mild alkaline hydrolysis, and their quantitative conversions were observed.
(1) For preparing RNA from rice plant leaves, the procedure described in the authors' preceeding paper was again modified. According to this schedule, the rice-RNA could be obtained more rapidly and more easily, with higher purity and homogenity, both from chemical and physicochemical points of view.
(2) Purine-to-pyrimidine ratio (Pu/Py) of the RNA from dwarf rice plants was from 0.88 to 1.34, the ratio of adenylic acid plus uridylic acid to guanylic acid plus cytidylic acid (A+U/G+C) of the same RNA was from 0.68 to 1.00. The values of Pu/Py and A+U/G+C of the RNA from healthy rice plants were from 0.73 to 1.28, and from 0.60 to 1.02, respectively. Nucleotide compositions of the RNA, therefore, appeared to be rather similar between healthy and diseased rice plants. It is, however, noticeable that the ratio of guanylic acid to adenylic acid is larger, and guanylic acid content of RNA is larger in the diseased plants than in the healthy plants.

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Some qualitative and quantitative studies of the carotenoid pigments were made with uredospores of Puccinia coronata Corda, uredospores and teleutospores of Stereostratum corticioides (Berk. et Br.) Magnus. The major pigment of all samples is γ-carotene, constituting about 60per cent of total carotenoids, and β-carotene comes next excepting uredospores of the latter species in which only a trace of it is present. Small amounts of flavochrome, cryptoxanthin and lutein are also detected in all the spores examined. The level of each carotenoid of S. corticioides, especially in uredospores, is considerably lower than that of P. coronata. In germinated uredospores of P. coronata which have been kept on the surface of water for 16hrs. at 20°-27°C, the amount of total carotenoids is only about 30per cent of that before germination.

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The causal fungus of trunk-blight of Xanthoxylum piperitum (L.) DC., which was named Nectria elegans by Yamamoto and Maeda, was identified by the writers as Hypomyces solani (Rke. et Berth.) Snyd. et Hans. [Fusarium solani (Mart.) Snyd. et Hans.].
Cross inoculations were carried out between this fungus and 7 forms and 2 races of Fusarium solani. This fungus was pathogenic only to Xanthoxylum piperitum and not to any host of the other forms of F. solani. On the other hand all the forms and races of F. solani tested were non pathogenic to Xanthoxylum piperitum. From these results, the writers propose the following nane for this fungus.
Hypomyces solani (Rke. et Berth.) Snyd. et Hans. f. xanthoxyli Sakurai et Matuo nom. nov.
[Fusarium solani (Mart.) Snyd. et Hans. F. xanthoxyli Sakurai et Matuo nom. nov.]
Syn. Nectria elegans Yamamoto et Maeda
Hab. in vivis xanthoxyli, cetra ut in typo¹⁰⁾
The type culture is deposited in Lab. Phytopath. & Mycol., Fac. Text. Seric., Shinshu Univ., Ueda, Japan, which was isolated from Xanthoxylum piperitum suffered from blight disease.
The sexuality of this fungus was studied. The results of reciprocal spermatization among the monoascosporic strains proved that this fungus is hermaphroditic and shows the compatibility heterothallism. Interformic fertility between this fungus and f. cucurbitae, f. mori and f. radicicola race 2 of Hypomyces solani was tested. But the interformic cross did not occur in every occasion.

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The differentiation in utilization of carbon sources among the intraspecific groups of Fusarium solani was studied.
Six forms and two races of Fusarium solani, i.e. f. cucurbitae, f. mori, f. xanthoxyli, f. phaseoli, f. pisi, f. radicicola race 1 and f. radicicola race 2 were used for the experiments.
Of 44 carbon compounds tested, l-arabinose, d-xylose, d-glucose, d-mannose, d-galactose, d-fructote, l-rhamnose, maltose, sucrose, d-raffinose, dextrine, starch, inulin, pectin, ethanol and gluconate were utilizable for all the forms and races used. But acetone, methanol, adonitol, cyclohexanol, oxalate, adipate and maleate were not utilized or utilized only a little by all forms and races.
The utilization of lactose, gum arabic, ethylene glycol, glycerol, erythritol, mannitol, sorbitol, dulcitol, inositol, malonate, succinate, fumarate, lactate, malate, tartrate, citrate and pyruvate was different among the intraspecific groups. γ group (f. radicicola race 1) utilized all of these compounds, and β group (f. pisi and f. radicicola race 2) utilized these compounds except citrate. The availabe kinds of carbon sources for α (f. cucurbitae, f. mori, and f. xanthoxyli) and δ (f. phaseoli) groups were less than the above mentioned kinds for γ and β groups, and the difference between α and δ group was recognlized in their ability to utilize tartrate.
l-Sorbose, cellulose, n-propanol and n-butanol were utilizable for some strains tested, but the utilization of them did not correlate with the differentiation of the intraspecific groups.

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1. This paper deals with serological experiments using the radish R and P virus. Radish R virus used as the immunizing antigen was the isolate “Miyahara 5”, which was obtained from a mosaic radish plant collected at Miyahara, Saitama Prefecture, November 1958, passed through tobacco and broad bean local lesions, and maintained by successive juice inoculations on turnip plants in a greenhouse. The radish P virus and the P antiserum used were the isolate Po, and the Po antiserum, reported previously. (Ann. Phytopath. Soc. Japan, 24)
2. By treating with chloroform, salting-out with ammonium sulfate, and differential centrifugation, a partially purified R virus preparation was obtained from infected turnip leaf juice. Antiserum was prepared by injecting rabbits with this virus preparation. The rabbits were given 6 intravenous injections (equivalent to total leaf juice volume of 250ml per rabbit), at 2-7 days intervals. The titer of the antiserum obtaind was 1:5120 in precipitation reaction. The antiserum did not react with leaf juice from healthy turnip plants.
3. Dilution end point was 1:32 in precipitation reaction with R virus, using infected turnip leaf juice. Reaction was, however, not detectable in agglutination reaction on slides.
4. The R antiserum reacted with leaf juice of turnip infected either with the radish R virus or P virus. In absorption tests, the R antiserum completely absorbed the radish R virus and P virus. Results with the P antiserum was almost the same. In precipitation reaction with either R antiserum or P antiserum, R virus always produced dense granular precipitates, while P virus always produced bulky and flocculent precipitates.
5. There was found only a slight difference in antigen-structure between R virus and P virus, as revealed in precipitation reaction, using infected turnip leaf juice.

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Tulip plants of the variety William Pitt were inoculated at different growing stages with tulip mosaic virus. The inoculum used was pressed leaf sap of naturally infected William Pitt showing typical flower breaking.
(1) Inoculation at post emergence stage: When the plants emerged above the ground, and attained 5-10cm in height, outer two leaves were rubbed with the inoculum added with carborandum. After about 40 days, when flowers bloomed, they were partly dark red and partly white (partial “break”). In the following year, flowers of the plants from these bulbs exclusively showed typical breaking.
(2) Inoculation at flower bud appearance stage; When three leaves were inoculated with the inoculum, all flowers showed dark streaks on the pink petal (self “break”). In the following year, all the flowers of the plants grown from these bulbs showed typical breaking.
(3) When tulip plants were twice inoulated until flower bud appearance stage, all flowers showed typical breaking in the current season.
(4) Inoculation at blooming time: No current season symptoms appeared in the plants inoculated at this stage. All the flowers of plants grown from these bulbs, however, showed typical breaking in the following season.
(5) Inoulation at blasting stage: About 20 days after the blooming time, partly blasted leaves were inoculated. In the following season, flower breaking of various types above stated appeared in plants grown from produced on each inoculated plant.
(6) It has been established that inoculation of pink tulip plants (vrieties William Pitt and Clara Butt) in an early developmental stage is most useful for detecting virus.
(7) It has also been established that color changes that take place in tulip flowers are mostly determined by the age of the plant when infected.

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Healthy tulip plants of the variety William Pitt were inoculated at blooming time with sap expressed from diseaed leaves of the following varieties: (a) Lincolnshire showing color-removing type breaking, (b) Feu Brilliant showing color-adding type breaking, and (c) William Pitt showing typical breaking, i. e., mixed color-removing and color-adding. In the following year, all the flowers of the inoculated William Pitt plants showed typical breaking, irrespective of the type of inoculum. It seems that various types of breaking in tulip flowers are not due to the kind of virus, but are rather due to genetic characteristics of tulip varieties.

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