Crepis Bursifolia L., Nuova Stabile Inquilina della Flora Ligustica della Riviera di Ponente

Abstract

«Crepis bursifolia » L., new permanent tenant of the flora in west ligurian coast. — The author declares the permanent presence of « Crepis bursifolia » L. in Liguria, and informs about new stations of this species along the western riviera. The relates, furthermore, the unfavourable results of his close investigation to verify the eventual presence of further station of « C. bursifolia » L. found by former researcher.     

Ricerche sulla flsiologia della produzione di tossine in colture di Helminthospobium maydis Nishik. et Miy

Abstract

STUDIES ON THE PHYSIOLOGY OF TOXIN PRODUCTION BY HELMINTHO-SPORIUM MAYDIS NISHIK. ET MIY. CULTURES. — Helminthosporium maydis produces under artificial culture toxic metabolites, which are responsible of a reduction of wheat and corn rootlets growth, severe alterations in tomato shoots and young corn plants, and growth inhibition of some microrganisms.

Cultural conditions for growth and toxin production were studied. Different strains of the fungus vary in their ability of toxin production, the highest amounts being produced by each strain by somewhat different conditions. At least one toxic metabolite can be extracted by chloroform from the cultural filtrates, but probably more than one toxin is produced, and of them at least one is not extracted with organic solvents. Toxic substances can be extracted from the mycelia, but it is not yet possible identify the toxins obtained by the extraction of the mycelia with one or more of the toxic metabolites obtained by extraction of the cultural filtrates.     

Identificazione di Alcuni Fattori di Crescita Nel Succo di Pomodoro

Abstract

Growth-factors in tomato juice. Raw juice of green and red tomato fruits contains 7 amines which can be separated by paper electrophoresis. These were identified as basic amino acids (arginine, lysine and ornithine) and aliphatic diamine and polyamines (putrescine, spermine and spermidine). These amines were found in tomato juice for the first time. One compound (band 6, table 1) was not identified. Putrescine, spermidine and the unidentified band, after elution, were assayed « in vitro » for the possible cellular proliferation of Jerusalem artichoke (« Helianthus tuberosus ») dormant tubers. The results show that the last three coumpounds must be considered natural growth-factors present in the raw juice of tomato fruits.     

Variazioni di Metaboliti Nel Seme di Ricino in Fase di Maturazione

Abstract

Changes of glycolytic substrates level during ripening of the castor bean seed. — The changes of the concentration of carbohydrates and of the main glycolytic substrates in the castor bean seed during the ripening phase were investigated. The following results were obtained:

The level of unphosphorylated sugars and of acid hydrolysable polysaccharides remains almost unchanged, with a tendency to a rise during the ripening phase. The slight increase of these compounds, together with the transition of the R. Q. from high to low values, might be interpreted as an indication of a shift of the seed from the a metabolism of fat synthesis to one of conversion of lipids into sugars, such as is observed in the germinating castor bean seeds.

Hexose monophosphate level sharply decreases during the last period of maturation. However, the level of these substrates does not fall so low as to suggest a severe limitation for the pentose-P pathway activity.

Fructose diphosphate, DOAP, GAP, 3 PGA, 2 PGA, PEP and pyruvate levels consistently increase during the ripening process. This indicates that the drop of oxygen uptake observed in this phase cannot be due to a lack of glycolytic substrates. On the other hand, the ratios between some substrates are shifted, during ripening, from values close to the theoretical equilibrium constants to quite different values. This finding, when correlated with the one of the strong decrease of the glycolytic flow, strongly suggests a severe inactivation of the glycolyting enzymes during ripening.

The increase of pyruvate in tissues showing a decreasing respiratory activity indicates a fall of the oxidative capacity of mitochondria. This might be due to a lack of ADP, or other high energy bond acceptor, following a block of synthetic processes. However, no decrease of ADP level, and an increase of the ADP/ATP ratio during ripening is observed, Among the alternative hypothesis: a) lack or excess of oxalacetate; b) increase of concentration of some Krebs cycle inhibitor; c) inactivation of mitochondrial enzymes, the latter is thought most probable, in view of the finding of a sharp decrease of some other enzyme activities during ripening, of the above mentioned interpretation of the shift of the ratios between glycolytic substrates, and of the very low level of mitochondrial activity in preparation from the mature castor bean seed. These results when correlated with those from parallel investigations on the biochemistry of castor bean seed maturation and germination suggest, as a working hypothesis, that the respiratory metabolic inactivation accompanyng seed repening is due to a general block of the metabolism of ribonucleic acid and thus protein synthesis.     

Prodromo della Flora Umbra

Defense responses of plants are activated not only in the wounded tissues but also in the remote parts of the plants. Two different methyl jasmonate (MeJA) treatments were conducted, i.e., MeJA solution spraying of entire rosettes leaves and pasting leaf surface with lanolin squares containing MeJA. Glucosinolate profiles in leaves were similar using the two methods of MeJA treatment except for indole glucosinolates. The glucosinolate profiles in local and systemic leaves showed that the accumulation of glucosinolates in systemic leaves were delayed comparing with those in local treated leaves. Comparative proteomics were used to investigate the molecular processes underlying the glucosinolate changes in response to local and systemic MeJA induction. A total of 83 unique proteins were detected as differentially expressed between the local and systemic leaves. Functional analysis showed that redirection of metabolism from growth to defense was differentially regulated in local and systemic MeJA induction. The higher contents of indole glucosinolates in systemic leaves might arise from the induction of a long-distance signal produced in local leaves as well as from JA synthesized in systemic leaves.     

Contributo alla conoscenza della Flora dei pascoli erbosi e boschivi di Monterotondo (Roma)

Summary

After having summarly described the ecological conditions of the area of the Roman Province which are studied by the author, he lists the plants collected and adds some critical remarks on the taxonomy. He gives a list of a few taxa, which must be regarded as having been found for the first time in Lazio, or are infrequent in this Province.

The author describes the vegetation of some pastures and woods by means of statistical investigations. Finaly he takes into consideration the reciprocal influence exerted by the various plant-communities.     

L'evoluzione della cerchia legnosa in Quercus Pubescens W. Ein Quercus Ilex L. nel clima di Firenze

Summary

The evolution of the wood ring in Quercus pubescens W. and in Quercus Ilex L. in Florence (from June 1946 to June 1947).

The present study deals with the anatomical characters of the wood ring of Q. pubescens and of Q. Ilex. In both the specimens the wood of the stem and of the young branch has been investigated.

In both plants studied the cambial tissue of the stem starts dividing at the end of April, reaching its maximum activity from May to June.

On the contrary the cambium of the branch differentiates in Q. pubescens a month earlier (18 March-18 April) than in Q. Ilex (18 April-18 May). While in the branch of Q. Ilex a false ring can be seen corresponding to the autumn months, nothing of the kind is found in the branch of Q. pubescens; though it presents a false ring in the stem.

It is difficult to date clearly the period when the cambium stops its activity, but probably it happens at the end of August in the samples of the stem.

The leaf buds of Q. pubescens and of Q. Ilex open during April-May and the young branch is completely developed at the end of June. In both oaks some buds open in autumn, but the small branches are prevented to develop because of the cold.

No comparison can be made between the opening of the buds and the beginning of the cambial activity in the stem and in the branch.

Considering the evolution of these woods and their relationship to climatic factors, we can see that the cambial activity starts during a period of remarkable rainfall and of regular increase of temperature, and stops almost completely at the end of July, when temperature and dryness reach their highest values.

The autumn rainfall would favour again a cambial activity, but the values of the temperature, regularly decreasing, do not allow it.     

Ritmo Dell'accrescimento Vegetativo in Olea Europaea L. Nel Clima di Firenze

Summary

The author has studied the grouth stages in the main stem of an olive-tree in Florence; the data obtained are compared with those from similar studies on trees of the same species in Bari and Camerino. In Florence, as in Camerino, the differences in habitat and climatic factors as compared with the Bari ones have noticeable effects on the cambial activity.

In Florence as in Camerino the rythmic wood production, typical of the trees growing in Bari (that is a region where the climatic conditions are more similar to those required by the species) occurs only in the autumn, while in the spring the process of wood formation is uninterrupted until summer. The period of rest in summer is very short.

The activity of the cambium, after the summer resting period, is renewed noticeably earlier in Florence than in Camerino, because of the more favourable climatic conditions, especially temperature.

In an exceptional growing period (March) an anomalous undifferentiated tissue is formed, the same that has been found in Camerino in August.     

Ciclo di Accrescimento E Differenziazione Delle Gemme in Piante Perenni Nel Territorio di Bari

Summary

Growth cycle and buds differentiation in perennial plants growing in Bari's area. — V. The evolution of the wood ring in Rhammus Alaternus L. from December 1946 to March 1949.

In Rhamnus Alaternus L. the cambium awackens in March with the production of an early wood, characterized by large vessels and loose fibers. It keeps on dividing the following months, producing intermediary wood, whose vessels become narrower and narrower. In June the wood ring is almost complete and the cambial activity slows down. In July late wood is formed, with narrow tracheae and highly lignified fibers. From August to February cambial activity is very scarce and irregular, in the wood produced fibers being tangentially compressed.

In a young branch of R. A. cambium becomes suddenly active in February, that is one month before than in the stem, it goes on during the month of March-June, with an evident diminution in the size of the wood elements. This diminution of size instead of being regular, shows some oscillations, expecially during the month of May. In Sept. the cambium starts again dividing, but rather poorly and irregularly, forming some vessels a little wider than the preceeding ones, so that an incomplete false ring is formed only in some points of the branch. As a rule the autumn wood is a typical late wood. This scarce and irregular cambial activity goes on also during Oct.-Dec. In January is more active and forms rather wide vessels in comparison with those formed in the preceeding month. This new formed wood however does not show the characteristics of the early wood of a new ring.

Concluding, the characteristics of the cambial activity of A. R. are

In the stem: 1) March: early wood. 2) March-June: intermediary wood. 3) July: late wood, resting period. 4) At the end of Autumn a scarce production of late wood is sometimes possible.

In the young branch: 1) February: early wood. 2) March-June: intermediary wood, with positive and negative oscillations in the vessels width. 3) At the end of June the late wood is already differentiated. 4) July-August: resting period. 5) Spt.-Juan.: the cambium starts again dividing very scarcely and producing a transition wood between the two rings. This wood can be regarded neither as a true ring nor a false one, it represents rather the last phase of the late wood formation. 6) In the young branch of the female specimen the cambium starts dividing somewhat later than in the male one. 7) The wood ring width does not vary much in relation to the yearly amount of rainfall. The lack of relation between rainfall and ring width is particularly evident in 1948 (a rainy year). The, «Compleasance» of R. A. could show that this species is, in Puglia, in its own habitat. On the other hand it is rather peculiar that R. A. forms only one wood ring during one year, with production of early wood during the spring, and of late wood in the autumn, instead of producing a second autumn ring following a distint summer rest, as could be expected.