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The removal of the apical buds from the top of inoculated pea plants before flowering caused the axillary buds of the stem leaves to develop and thus further to branch. The vegetative growth of the test plants continued to be luxuriant when blooming was delayed. While the control plants formed seeds and ripened, the vegetative growth of the stem of the test plants increased at most eight-fold during the same time. A new, addition at red part grew at the same time in the root nodules, which had already partly become green. The new red part branched later so that the unusually large nodules appeared quite odd. The weight of the branched, large nodules had at the same time increased on the average six-fold and the vegetatively grown test plants synthesized even eight times more nitrogen than did the control plants. The concentration of teghaemoglobin in the nodules formed by the bacterial strain used in the experiment was not increased, but the absolute amount of the pigment was raised six-fold as a result of the increased nodule mass. While the vegetative growth was going on, oxidation of the leghaemoglobin was delayed. Analyses of nitrogen and amino acids were made for both test and control plants. The total length of the branches in the largest test plant was 32 m compared with the unbranched control plant which was 1.30 m. [ABSTRACT FROM AUTHOR]

Besides the molecular nitrogen fixed in its root nodules, Hedysarum coronarium is able to use also different nitrogen compounds added to the medium. Inoculated Hedysarum grew best in the experiments performed. With combined nitrogen the best nitrogen source was a mixture of ammonium- and nitrate-nitrogen. Factors which probably influence the utilization of combined nitrogen are indicated in the investigation. In any case, there is not difference in principle in the utilization of the nitrogen sources between Hedysarum coronarium and other leguminous plants. [ABSTRACT FROM AUTHOR]

1. An ethanol extract of Calligypona pellucida injected into young oat plants greatly retarded their growth. No panicles were developed but numerous tillers were formed. Some of these developed panicles later on. No unusual changes in the colour of the leaves were observed. The results varied somewhat in different experiments, depending on the stage of growth at injection and, of course, on the amount of extract injected. Injection of water did not prevent the formation of panicles on the main shoots, although it slightly retarded growth in height, and promoted the formation of tillers to some extent. The difference between the plants injected with water and with extract was very great. 2. About 50-60 per cent of the active substance was dissolved in n-butanol from the ethanol extract. On fractionating the clear butanol solution thus obtained on a cellulose powder column, the active factors which inhibited growth and panicle formation was found to occur in fraction 4. Amino acids emerged from the column only from fraction 12 onwards. No inhibitory effect was found in fractious 12 and 13. 3. The results suggest that the growth-inhibiting factors in straight-growth test with oat coleoptiles was also responsible for the prevention of growth in height of the main shoot and panicle formation. 4. No amount of free amino acids worth mentioning was found in the salivary glands of Calligypona pellucida. Neither was 3-indoleacetic acid detected in these glands. 5. The disease symptoms in oat plants injured by the ethanol extract obtained from Calligypona pellucida were essentially similar to the disease symptoms caused in oats by the oat sterile-dwarf virus, which is known to be transmitted by the leafhopper in question. A positive correlation existed between the severity of damage to oats in the field and the damaging effect of leafhopper extracts obtained in three different years. Our sincerest thanks are due to Mr. Teuvo Suominen and Mr. Raimo Hissa for carrying out the laborious task of collecting the leafhopper material from the area of oat damage during the year 1958 and to Mrs. Saara Kivinen, Miss Tuula Mäntyniemi, Mr. Matti Kivinen, and Mr. Pentti Kivinen for making the collections during the years 1959 and 1960. [ABSTRACT FROM AUTHOR]

Experiments with associated cultures of alder and spruce in quartz sand without combined nitrogen are reported on in this paper. The experiments were started in 1931 and finished in 1942. The results and the arrangement of the experiments from the first year (1931-1934) have been reported in detail earlier. There present results show that the spruce has obtained nitrogen fixed in the root nodules of alder although leaves falling in autumn were always carefully removed from the surface of the sand. Data are also given on the amounts of nitrogen fixed by the root nodules of the alder during the first 7 years. [ABSTRACT FROM AUTHOR]

1) Paper chromatographic analysis revealed that citrulline is the predominating free amino acid in the root nodules of A. incana and A. glutinosa throughout the year. In autumn its concentration has increased 5-10 fold, compared with the summer value. 2) The nodules of A. incana contain in addition to citrulline much γ-amino butyric acid, which evidently is formed from L-glutamic acid, since L-glutamic acid decarboxylase aclivity was found to be present in the insoluble residue of the crushed nodules. 3) The roots of A. glutinosa contain in addition to citrulline much arginine and ornithine but the nodules have only traces of them. The concentration of free amino acids in the roots near to the nodules is about 5 times that in the more remote parts if calculated per unit dry matter. 4) The completely unnodulated roots of uninoculated alders grown on combined nitrogen also contain citrulline, hence, it is not a compound specific to nitrogen fixation. 5) The stems and especially the leaves of alder contain considerably less citrulline and soluble nitrogen in general than the roots of the same plant. 6) The presence of urea and the identity of citrulline were tested paper chromatographically using p-dimelhylaminobenzaldehyde reagent. Only in unnodulated roots was urea found and then only in very small quantities (about 0.005 per cent of dry wt.), possibly as the result of a secondary splitting. The identity of citrulline in all extracts was confirmed. 7) The arginase activity of the alder nodules, roots and leaves was tested. No activity could be detected. 8) The amino acids extracted with ethanol were separated from many impurities in the extract by means of alkaline ion exchange resin Dowex 2. 9) L( + )-citrulline was also isolated from the nodules of A. incana as the Cu-salt. This was identified by means of the mixed melting point with the authentic Cu-L(+)-citrullinate. 10) In the nodule extract of A. incana two unknown compounds were found, possibly peptides, which disappear in the HCl-hydrolysis. Simultaneously alanine, glutamic acid, some glycine and possibly γ-amino butyric acid are set free. 11) Citrulline was noted to break down to a great extent to ornithine in the HCl-hydrolysis. 12) In one preparation citrulline was also determined photometrically by diacetylmonoxime reaction. 13) Hypotheses are advanced on the significance of the observations. [ABSTRACT FROM AUTHOR]