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| Registros recuperados: 119 | |
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| Brieger,F. G.; Forster,R.. |
| The present paper gives some observations on the tumour formation and other abnormalities observed in the interspecific hybrids, Nicotiana glauca x N. Langsdorffii and N. glauca x N. Sanderae. Without entering into a detailed discussion of the literature and the various speculations proposed by Kostoff and Whitaker about the causes of tumour formations or on the relations between "spontaneous" and pathogenic tumours (Kostoff, Levine and others), two new observations are described. 1) The abnormalities in the two above mentioned hybrids are quite different. As already reported by other authors, the hybrids N. glauca x N. Langsdorffii are initially quite normal and vigorous, while tumours and other proliferations, on the stem, the stem base and the root... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1942 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87051942000700002 |
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| Mendes,A. J. T.. |
| The ovule of C. arabica L. consists õf a single integument and a small nucellús which disappears as the ovule matures. Three of the four macrospores resulting from the'division of the macrosporocyte, degenerate. The remaining chalazal cell gives rise to a "normal'' embryo sac, which is ready for fertilization at the time of the flower opening. Double fertilization occurs, as a rule, the day the flower opens. The embryo sac then increases in volume and compresses the inner integument cells. The outer cells of the integument, however, multiply actively, giving rise to the "perisperm". After degeneration of the synergids and antipodals, the zygote stays near the micro-pyle in a resting stage, while the primary endosperm nucleus divides. This first division of... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1942 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87051942000400002 |
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| Medina,J. C.; Jensen,G. O.; Neri,J. P.. |
| A study was made of the chemical composition of samples of the ribbons taken from the rami stalks at successive stages of growth with the object of determining the percentage oí lignin, cellulose, pectin, pentosans and of some substances not belonging to the cell wall. After an initial decrease, the percentage of ash increased as the plant grew and matured. The maximum (17,5%) was reached when the plant was 105 days old. The percentage of cellulose increased regularly and reached a maximum (38,2%) when the plant was 75 days old. Subsequently there was a decrease as the plant grew older. After an initial increase, the percentage of lignin decreased somewhat and again increased as the plant matured. The maximum (14,5%), however, was observed when the plant... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1942 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87051942001100001 |
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| Krug,C. A.; Carvalho,Alcides. |
| Em artigos anteriores (1, 2) os autores demonstraram que a cor amarela dos frutos e a coloração bronzeada das folhas novas são, em Coffea arabica L, controladas, cada uma, por um único par de fatores genéticos (respectivamente xc xc e Br Br). Os híbridos F1 no primeiro caso com plantas de frutos vermelhos, e no segundo com plantas de folhas novas verdes, demonstraram tratar-se de casos em que há dominância incompleta nesta geração, os frutos híbridos possuindo uma coloração vermelho clara e as folhas novas se apresentando com uma tonalidade bronze clara. Como algumas das hibridações realizadas envolviam, ao mesmo tempo, os dois caracteres em questão, apresentou-se a oportunidade para constatar se havia ou não independência entre os dois pares de fatores... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1942 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87051942000600002 |
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| Graner,E. A.. |
| The inheritance of two characters in Manihot utilissima Pohl were studied. It was found that the leaves with narrow lobes V (Fig. 1) are dominant over leaves with large lobes v (Fig. 2) and that the brown coloration of the roots M (Fig. 5) is dominant over white m (Fig. 6). These two characters segregate independently, according to the dates recorded in tables III and IV. The phenotypic expression of the form of the leaves is largely dependent from the environment, the leaves with narrow lobes being replaced by leaves with large lobes in plants transported to a shady place under big trees. (Figs. 3 and 4). Thus reduction of light causes a change of dominance. |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1942 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87051942000100002 |
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| Paiva Neto,J. E. de. |
| In the beginning of this work a brief idea was given on what is understood as "clay", on the scientific methods applied to the study of the matter "clay" as well as on its conception with regard to the edaphic studies. A description is given of the methods of total and natural mechanical analyses which were employed in the agro-geological Department. The work is illustrated by a graphic showing the fractions of the mechanical analysis of the chief great soil types of the State of São Paulo. The fraction clay is then studied by chemical way in the following sequence : 1.° total chemical analysis, 2.° partial chemical analysis, 3.° chemical analysis of the Helmholz layer and 4.° study of the fixation of the ion Ca+ + in the already mentioned Helmholz layer.... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1942 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87051942001000001 |
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| Brieger,F. G.. |
| The object of the present paper is a study of the usefulness of two relative measures of variation, the well known coefficient oj variation and a new term proposed in this paper and called the index of variance. These terms are defined by the equations : coefficient of variation : σ% = s /v/v. 100 index of variance :σ/ √. 1. It is shown that, for theoretical reasons, only the index of variance may be expected to be constant. Six different experimental series actually proved this constancy, showing at the same time the variability of the coefficient of variation which proved to be dependent upon the respective mean. The coefficient of variation becomes approximately constant when the respective means are sufficiently distant from the absolute limit zero or... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1942 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87051942000900001 |
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| Forster,R.. |
| Observations were made with tobacco plants which, after being naturally infected in the field by the virus of "vira-cabeça", a disease identical to spotted wilt (3), not only resisted to it, but exhibited complete recovery. Several trials were carried out in order to ascertain the following points : 1) whether the recovery means a greater degree of individual constitutional resistance ; 2) whether it represents an acquired immunity or ; 3) whether it is just of pure accidental nature. Plants showing recovery were selfed and seeds collected from them sown in separate rows. The same procedure was always applied with the new recovered plants. Thus, strains of plants were obtained representing several succeeding generations of recovered plants. In 1940-41... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1942 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87051942001200002 |
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| Franco,Coarací M.. |
| Knudson's asymbiotic method and medium for germination of orchid seeds were used with success. Heating this medium at 100°C twice for 15 minutes with an interval of 24 hours was found to be better than to sterilize just once at 120°C. This procedure avoids the hydrolysis of the agar. The poor quality of the glass from which some test tubes were made raised the pH tabove 5.9 and this was apparently the cause of poor developmen of the seedlings. Also some toxic elements given off by the glass diffusing thru the medium might havo impaired somewhat the results obtained in the experiment. |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1942 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87051942000700001 |
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| Mendes,A. J. T.. |
| 1. Plantas tetraplóides e octoplóides foram obtidas de sementes de Gosjypium herbaceum e G. hirsutum, tratadas com colchicina. 2. As sementes de G. herbaceum eram bastante homozigotas e reagiram em regra mais uniformemente para o alcalóide do que as de G. hirsutum. 3. A microsporogênese em G. hirsutum octoplóide (2n = 104) é descrita com algum detalhe; algumas irregularidades cromosômicas foram observadas; os grãos de polen são maiores que os das plantas tetraplóides normais. A despeito de se encontrarem raros grãos de polen "vazios", as plantas são altamente estereis. As anteras são quase sempre indeiscentes. 4. Não se conseguiu frutificação quando as flores com anteras deiscentes foram autopolinizadas e quando outras flores foram polinizadas com polen de... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1942 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87051942000300003 |
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| Krug,C. A.; Mendes,P. Teixeira. |
| In the introduction to this article data are presented to show the growing economic importance of the cultivation of Ricinus in Brasil and particularly in the State of São Paulo. Following general statements regarding the botany, the origin and the geographic distribution of this genus, the investigations are outlined which are carried out by the Divisions of Genetics and Oil Plants of the Instituto Agronômico of the State of São Paulo, Brasil, to improve this important crop plant. Summarising, these investigations deal with the following subjects : a) Organisation of a large collection of types ; b) Investigations concerning the variability of the genus Ricinus c) Genetic analysis; d) Regional variety trials ; e) Improvement of the best varieties by... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1942 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87051942000500001 |
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| Brieger,F. G.; Gurgel,J. T. A.. |
| The occurrence of polyembryonic seeds in Mangifera indica has been known for a long time, but nothing is known with reference to the forms cultivated in Brazil. It was found impossible to count the number of embryos in the seed, in spite of the size of both seed and embryo. But the cotyledons are in such a way twisted around each other that it is impossible to separate them. Thus it was necessary to take into acount only the embryos which were able to germinate and their number was determined after 3 and 7 months. It was necessary to dig up the seedlings and wash off all soil in order to distinguish ramifications of shoot and root from the actual polyembryony. In 7 months old seedlings a new complication arises owing to the complete fusion of their base.... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1942 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87051942001200001 |
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| Germek,Emílio. |
| A description is given of a new method for the production of seedlings in planting of rice strains. This method has been used these three last years in connection with the improvement work on rice in the "Instituto Agronômico". Perforated cylinders, 14 cm high and 18 cm diameter, are distributed over the seed bed and the seeds of each strain sown inside. A week afterwards the cylinders are pulled up and used again. With this method seedlings are obtained with great facility and perfect separation between strains thus avoiding mixture of seeds. |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1942 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87051942001200003 |
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| Brieger,F. G.; Lima,A. Rodrigues; Forster,R.. |
| 1) The object of the experiment presented in this publication was a detailed comparison between progenies of the varieties Virginia and Sumatra of the collection of the Instituto Agronômico de Campinas. We intended to decide whether these strains were sufficiently heterogeneous to permit further selections or whether they were already so uniform as to allow a reduction in their number within our collection. 2) A preliminary experiment in 1939/40 showed clearly that some of the 7 types introduced as Sumatra were less resistant than others, and the experiment was thus continued "with only four of them. 3) The lay-out of the final experiment was such as to permit both a complete analysis of soil heterogeneity and of differences between the genetically... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1942 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87051942000800001 |
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| Costa,A. S.; Forster,R.. |
| The present paper deals with the virus disease of the tobacco plant recently described by Kramer & Silberschmidt (12) under the name "faixa das nervuras" (veinbanding). New host plants are added to the list of suscepts, as follows : Nicotiana repanda Willd., JV. angustifolia (*), N. Gossey Domin, N. Sanderae Hort. ex. W. Watson, N. glutinosa L., N. longiflora Cav., N. paniculata L., Lycopersicon esculentum Mill., L. pimpinellifolium Mill., and Cyphomandra betacea Sendt. Datura stramonium L., already studied by Kramer & Silberschmidt (12) and Nicotiana glauca Grah., Nicandra physaloides Gaertn., Solanum nodiflorum (**), S. nigrum L., Lactuca sativa L., Brassica oleracea L., Vigna sinensis Endl. var. Black., and Dolichos lablab L., var.... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1942 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87051942000200002 |
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| Paiva Neto,J. E. de. |
| The present work is a study of Vageler's formula y =x.S/ x+y.S for the determination of the final value of the reaction of the cation change in the sorptive complex of the soil. The author took the changeable H+ of the soil as a cation to be examined. Samples studied by the author belong to a chain (a series of soil profiles with 5 horizons each) taken from the original red soil ("terra roxa") of the Ribeirão-Preto Experiment Station. In these samples, as a rule, H+ changed could be considered = T - S, because the Al changed, as far as it existed, was traced in very low percentage, as can be seen in table I. For the determination of T - S, the author used a solution of (CH3COO)2Ca N/l (normal calcium acetate). As a mean of extraction, the percolation of... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1942 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87051942000900003 |
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| Krug,C. A.; Carvalho,Alcides. |
| A variedade maragogipe do Coffea arabica L. foi encontrada pela primeira vez por Crisógono José Fernandes, em 1870, no município baiano de Maragogipe onde, provavelmente, se originou por mutação. Desde 1933 esta variedade vem sendo estudada pela Secção de Genética do Instituto Agronômico do Estado de São Paulo, em Campinas, com o fim de se determinar a sua constituição genética. Muitas autofecundações, cruzamentos e back-crosses foram, então, realizados. Grande parte das plantas obtidas só puderam ser classificadas após a colheita do ano de 1940. Todas foram examinadas quanto à forma e dimensões das folhas e um grande número ainda quanto à forma e dimensões das flores, frutos e sementes. Verificou-se que o caráter maragogipe mostra dominância quase... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1942 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87051942000600003 |
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| Krug,C. A.; Mendes,P. Teixeira. |
| Ninety six varieties of Ricinus communis, L. were studied as for their growth habit, height, length and number of internodes from the base of the plant to its first inflorescence, types of branching, color of branches and various characters of leaves, inflorescences, fruit clusters, fruits and seeds ; earliness ; yielding capacity and porcentage of oil in the seeds. The description of several of the quantitative characters is supplemented by numerical data, which are also presented graphically. The extreme variability of Ricinus offers excellent opportunities not only for genetical studies but also for breeding new and better varieties for cultivation. |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1942 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0006-87051942000500002 |
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| Registros recuperados: 119 | |
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