Significato dei Tegumenti in Cariossidi di Triticum Durum Desf. Trattate Con Raggi X

Abstract

Significance of integuments in caryopses of « Triticum durum » Desf. treated with X-rays. Experiments were carried out on Triticum durum « Cappelli », to test the influence of seed coats on the damage by X-rays. The damage was evaluated in terms of germination, seedling growth and chromosomal aberrations. Seeds in which the embryo was covered (with pericarp and spermoderm), uncovered (without pericarp) and bared (without pericarp and spermoderm), were irradiated at the total exposure of 1000, 2000 and 4000 R of X-rays. The growth of seedlings coming from covered and uncovered embryos, X-rayed at 1000 R, results better than that of bared embryos. The chromosomal aberrations analysis carried out in root meristem cells at anaphase, during the first mitotic cycle, show the highest damage in seedlings coming from uncovered and bared embryos and the type of aberrations was almost chromatidic (B'). We therefore forward the hypothesis that the removal of the integuments (pericarp and spermoderm) could possibly accelerate the process of germination, and could also produce in the embryo a greater sensitivity to X-rays.     

Osservazioni Preliminari sui Sistemi Degradanti dell'RNA nei semi di Ricino

Abstract

Preliminary observations on the enzymatic degradation of RNA in castor bean seeds. — Cocucci, Maggio, Monroy and Marrè have shown the decrease of RNA content during ripening in castor bean seeds, and its increase during germination. Furthermore, these Authors have demonstrated that in the dry ripe seeds the ribosomes are undetectable, and that they increase rapidly during germination. Two peaks of ribosomes are easily detected upon ultracentrifugal analysis in germinating seeds (Cocucci and Sturani). These observations were the basis for our investigations of the enzymes of RNA metabolism in castor bean seeds. This paper deals with our preliminary observations on RNA degrading enzymes in these tissues. We have been able to measure RNase activity, phosphodiesterase, 3′-,5′- and 2′-nucleotidases in castor bean seeds at different stages of development. RNase activity (measured in crude extracts) changes little during the ripening process, its rate corresponding to 40–50 μMoles of nucleotides liberated from RNA per hour and per gram of fresh weight. In the dry seeds, RNase activity is 30–40 μMoles of nucleotides/h.g.f.w., and it increases to about 60–70 μMoles/h/g.f.w. after 72 hours of germination.

Phosphodiesterase activity is about 4–5 μMoles/h.g.f.w.

The following rates have been found in seeds almost completely ripe seeds for 3′-, 5′- and 2′-nucleotidase activities, respectively 45–50 μMoles/h.g.f.w.; 6–7 μMoles/h.g.f.w.; 8 μMoles/h.g.f.w.; ATP-ase activity was of about 80–100 μMoles of phosphate liberated /h.g.f.w. - The high activity of 3′-nucleotidase, of the same order of that of RNase, suggests that these two enzymes are responsible for degradation of RNA to nucleosides and inorganic phosphate. Further investigations are being carried on to define the biochemical properties of castor bean RN-ase.     

Ricerche Sulla Vegetazione dei Dintorni di Firenze

Summary

It is related on some phytocenoses of the southerly Florence hills, lying on the boundary of the two basal biochores of peninsular vegetation. Although the proximity and the chorographical analogy at the south-westerly ones and at Ceceri Mount, which are included yet in the » Quercetum Ilicis « ambit, these hills are whereas sensible displaced in the » Quercetum pubescentis «. They have microtherme elements of higher planes, but they have in yet the marks of littoral biochore, for instance Smilax aspera, abundantly penetrating in hedges and in a pine-grove but non in coppices of Quercus Cerris.     

Ricerche Sulla Vegetazione dei Dintorni di Firenze

Riassunto

L'A. espone in questo lavoro i risultati di ricerche sistematiche e fitogeografiche sulla vegetazione di Monte Ferrato (presso Prato in Toscana), piccolo gruppo di colline costituite da rocce ofiolitiche (serpentino, eufotide ecc.), Dopo averne elencata la florula, dove riporta anche le diagnosi di alcune forme nuove, l'A. prende in esame la vegetazione dei principali tipi di stazione, che vi ha potuto riconoscere, in base a criteri fisionomici e statistici. Considera poi le caratteristiche morfologiche delle specie pi[ugrave] significative del serpentino, che raggruppa in cinque tipi di speciali morfosi. Sulla base dell'analisi della distribuzione geografica di alcune notevoli entità che si presentano a M. Ferrato in stazione disgiunta rispetto al loro areale, dello studio geografico e sistematico degli endemismi, e in genere poi di tutte le specie pi[ugrave] significative di questa Flora, l'A. ne discute il valore fitogeografico e climatico, rilevando e discutendo la convivenza di specie di diverso valore fitogeografico, in rapporta alle particolari condizioni microstazionali.     

Osservazioni Sulla Germinazione Asimbiotica e Simbiotica di Alcune Orchidee

Abstract

Anthocyanins are secondary metabolites, which play important roles in the physiology of plants. In tomato (Solanum lycopersicum L.), anthocyanins are normally synthesized only in vegetative tissues. M375 is a mutant unable to produce anthocyanins in leaves and stems. In this study, we investigated the anthocyanin biosynthetic pathway in M375 and in its genetic background, Alice, in order to find out where the anthocyanin biosynthesis is blocked, along the pathway, in the mutant. Anthocyanins accumulation was enhanced by sucrose only in the wild type, even though the expression of several genes involved in anthocyanin biosynthesis was normal in both the genotypes. Genes coding for the final steps along the anthocyanin biosynthetic pathway were, however, less expressed in the M375 when compared to the wild type.     

Osservazioni Preliminari Sull'ecologia di Semenzali di Rovere (Quercus Petraea (Matt.) Liebl.)

Abstract

Preliminary observations on the ecology of sessile oak (Quercus petraea (Matt.) Liebl.) seedlings.—The responses of sessile oak seedlings to four different light intensities and to increasing drought (three soil moisture contents) have been investigated in a nursery experiment in order to improve the knowledge of the ecology of this species in the Mediterranean area. Data have been compared with observations on natural regeneration established in different shade and soil moisture conditions in a sessile oak stand. The results of the two experiments showed that low light intensities (transmittance <5%) did not limit the seedlings establishment but induced lowest growth rates, while in full daylight seedlings mortality was very high (61%). In accordance with the observations in natural conditions, seedlings showed the best performances at intermediate light levels (50–80% of full daylight) and with increasing soil moisture: mortality was very low and average height increment, dry weight, relative growth rate (RGR) and net assimilation rate (NAR) showed the highest values. The differences in specific leaf area (SLA), leaf area ratio (LAR), root/stem ratio enabled to discuss the sessile oak seedlings ecology and adaptations to different light intensities and soil moisture content.     

L'amido E L'endosperma Delle Cariossidi Dure E Tenerizzate Di Triticum Durum Desf

Abstract

Starch and endosperm of vitreous and starchy (yellow-berries) kernels of Triticum durum Desf. — Starch and endosperm in kernels of T. durum Desf. have been examined in relation with the problem of the origin and nature of the vitreous or starchy texture which this tissue shows in the ripe fruits. This research has demonstrated that the starch of the vitreous differs from that of the starchy kernels in the shape, respectively irregular and regular; in the distribution of the frequencies y versus the length of the diameter x which is exponential and of the type log y = log a — x log b, in the vitreous kernels the value of log b is generally lower than in the starchy kernels; in the submicroscopical texture, because the irregular grains of the vitreous kernels do not show either birefringence or polarisation cross and are coloured with Congo red: starchy kernels behave quite differently. The starchy kernels are also more swollen and regular, their apparent specific weight and their nitrogen content being less than in the vitreous; the process of starchiness is always in close contact with fibro-vascular bundle of the row; in the starchy cells the cytoplasm shows some interruptions of continuity which leave partly uncovered the starch grains; the endosperm and the starch of the hard kernels wetted with water or placed in moist atmosphere become micro- and macroscopically similar to the starchy ones; in the starch the process of trasformation of the orderly into the amorphous texture is reversible, but for this to happen the only contact with water is insufficient; according to the treatments the vitreous kernels might show a decrease in their nitrogen content. Both starch types are connected with the presence orabsence of slightly bound water; the hypothesis which considers the nitrogen supply of the fruit as immediate cause of the endosperm texture is criticised and it is considered more plausible that such cause might be the different structure and texture of the cytoplasmatic gels during, in function of temperature and moisture.     

Osservazioni Sulle Infrastrutture di Anabaena Cycadinae E delle Cellule dei Tubercoli Radicali di Cycas Revoluta

Abstract

Observations on the infrastructures of ANABAENA CYCADINAE and of root-nodules cells of CYCAS REVOLUTA. — Light and electron microscope observations carried on the fine and ultrafine sections of root-nodules of Cycas revoluta, brought in evidence differences structural and infrastructural of cells. These differences concern mainly the modifications presented by reticulum endoplasmic which in middle-aged cells takes a fragmentary and vescicular aspect, and the mitochondria which, in the same cells, show short cristae starting by outside wall of the organul.

About the plastyds, I could bring in evidence that there is plenty of leucoplasts but the proplastyds are still numerous, as the cloroplastyds showing some development of the lamellar system and of grana. Plastyds green are present either in while nodules, either in the root-tops.

In no nodules it has been possible to point out the presence of bacteria while it has been possible to verify that Algae have some polymorphism of structure because the chromatoplasma may result essentially of tree different aspects, by me, indicated as reticular type (fig. 12), lamellar type (fig. 10) and type at mixed structure (fig. 11).     

Osservazioni Sulla Maggiorana (Origanum Majorana L.) in Veste di Pianta Coltivata

Abstract

Stomatal features and ontogeny of stomata of 11 ornamental taxa of monocotyledonous families with Agavaceae (1 species), Amaryllidaceae (1 species), Araceae (3 species), Cannaceae (1 species), Commelinaceae (3 species), Liliaceae (1 species), and Musaceae (1 species) have been studied. Features like stomatal area, leaf area occupied by stomata and per cent leaf area occupied by stomata are reported for these taxa for the first time.     

Influenza Dei Tegumenti Dell'Embrione Sull'Azione Dei Raggi X In Semi Di Triticum Durum Desf

Abstract

Influence of seed coats on the effect of X-rays on the embryo of «Triticum durum» Desf. – Seeds of «durum» wheat «Cappelli», presoaked in distilled water at 20° C. for 24 h in the dark, were treated with X-rays 0.5, 1, 2, 4 and 6 KR. Before irradiation, seeds were distributed among the following three groups: 1) normal seeds with covered embryos; 2) seeds to irradiate and afterwards to submit to the removal of seed coats (pericarp and spermoderm) on the embryo; 3) seeds to irradiate after having removed seed coats on the embryos. Of course, for every group, the respective unirradiated controls were prepared. The material was sown in sterilized sound and kept in termostatic chamber at 20°C in the dark, for 7 days. After 4 and 6 days the seedling emergence was registered, after 7 days seedling were measured. Of particular interest is the remarkable depressing effect on the growth of seedlings coming from bared and irradiated embryos: this effect is induced – for significant differences, as compared with the behaviour of materials of groups 1 and 2 – especially on the root, by X-rays 2, 4 and 6 KR. No difference there is, on the contrary, among the seedlings coming from irradiated and bared embryos and those coming from irradiated controls.     

Azione della luce sulla crescita allo stadio di plantula di un mutante clorofilliano di Triticum durum Desf

Abstract

ACTION OF LIGHT ON SEEDLING GROWTH IN A YELLOW-GREEN MUTANT OF TRITICUM DURUM DESF. — Dry grains of Triticum durum cv. « Cappelli » and its radiation-induced yellow-green mutant were sown in sand in four environment, different for light conditions (daylight, artificial light, ultraviolet rays, darkness), having all the same temperature (23°C.). Seven days after sowing, the following data were registered: a) growth (in cm.) of the shoot and of the longest root; b) fresh weight (in gr.) of shoots and roots; c) water content of shoots and roots.

The following main results were obtained:

1. the yellow-green mutant always shows less growth and less weight increase than normal « Cappelli », with the exception of the seedlings grown at daylight, which have shorter shoots and longer roots than the normal « Cappelli » but the same weight:

2. artificial light, besides depressing the growth of the roots of the yellow-green mutant, which becomes green under these conditions, induces a remarkable decrease in the water content of the roots of the two wheats.

     

Evoluzione Biochimica Delle Sostanze Nutritive di Riserva dei Semi di Triticum Ramosum Albo. Riassunto

Abstract

Biochemical evolution of the reserve nutrients in TRITICUM RAMOSUM albo seeds. — The author refers on his further experiments of cultivation of Triticum ramosum typicum and Triticum ramosum hyblaeum, and of chemical analisis of reserve nutrients of the seeds.     

硬粒小麦基因组中疑似硒蛋白生物信息分析

目的：用生物信息学的方法对硬粒小麦基因组中疑似硒蛋白的氨基酸序列进行综合分析,进一步找寻其为硒蛋白的生物信息依据,并初步分析推断其功能。方法：利用Vector NTI等多种生物信息学工具对硬粒小麦AYl46587．1序列中发现的疑似硒蛋白编码序列进行综合分析研究。结果：发现2段目标编码序列具有与某些蛋白酶相似的生物信息学特征,并推测其蛋白编码具有目前未知的机理。结论：推断AYl46587．1序列中存在编码未知硒蛋白的编码段,其编码的硒蛋白参与硬粒小麦胚芽生长发育时期能量调节。     

Relevance of RAPD Analysis for Revealing Phylogenetic Relationships between Cultivars of Durum Wheat Triticum durum Desf.

A comparison of similarity indices between 64 durum wheat cultivars calculated using pedigree analysis and RAPD method showed a correspondence between these two approaches to estimation of genetic diversity. The associations between the results of RAPD clustering and coefficients of parentage (² test) and the coefficient of correlation between similarity matrices were statistically significant. However, the correlation was rather weak while pedigree analysis and RAPD method did not yield completely identical estimates of genetic diversity in the set of cultivars studied.     

硬粒小麦基因组中硒蛋白存在性分析研究

目的：用生物信息的方法对硬粒小麦基因组中硒蛋白存在性进行分析研究。方法：利用SECISearch工具将Genebank中收录的11029条硬粒小麦核酸序列逐个分析,找出具有符合硒蛋白特有茎环结构的序列,以已经发表的衣藻中硒蛋白为参照对象,利用VectorNTI软件对匹配序列进行生物信息分析,研究硬粒小麦硒蛋白存在性。结果：发现AY146587．1序列的互补序列中存在一个表达区与衣藻硒蛋白具有较高的结构相似性（该序列区长度为288bp,对应的SECIS在其下游6071bp处）,很有可能是硬粒小麦硒蛋白（或同源蛋白）编码区。结论：获得硬粒小麦中可能与硒蛋白相关的核酸序列。