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| Registros recuperados: 6.820 | |
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| Duarte,Jair Moura; Santos,João Bosco dos; Melo,Leonardo Cunha. |
| The genetic divergence of 27 common bean (Phaseolus vulgaris L.) cultivars from different races was evaluated using RAPD markers. The association of this divergence with some indirect variability estimates obtained in field experiments was also assessed. Genetic distances were calculated using Sorensen-Dice's similarity coefficient, displayed in a dendrogram (UPGMA method), and by projection in two-dimensional space. Analysis of molecular variance (AMOVA) was used to evaluate the distribution of variance between and within domestication centers. RAPD marker genetic diversity within these centers was also calculated. The correlations between estimates of genetic distances obtained with RAPD markers and estimates of Mahalanobis' generalized distances,... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47571999000300023 |
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| Oliveira,Antonio Carlos Baião de; Sediyama,Carlos Sigueyuki; Cruz,Cosme Damião. |
| Several different selection strategies were used to estimate expected gain of days to flowering and other related characters in two F2 soybean (Glycine max (L.) Merrill) populations. The sample originated from crosses of lines whose seeds do not contain the three lipoxygenase isozymes with the commercially cultivated IAC-12. IAC-12 is a gene carrier for an extended juvenile period. This study was conducted during the winter of 1994 in Viçosa, Minas Gerais. The plants were grown under natural photoperiod. One population was grown in a heated greenhouse, and the other in the field under natural temperature conditions. Lower temperatures early in the field planting caused a delay in flowering. Delayed flowering caused a broader amplitude in all characters... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47571999000200019 |
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| Carvalho,Samuel Pereira de; Cruz,Cosme Damião; Carvalho,Claudio Guilherme Portela de. |
| It was shown that the classic selection index, under multicollinearity, could not give simultaneous gains for wheat grain production and its primary components. This was due to the instability and, consequently, low precision of the coefficient index estimates. A modification of the prediction process of the index was proposed to avoid the adverse effects of multicollinearity, adopting a procedure based on ridge regression theory. The modified classic selection index, or ridge index, gave more statistically viable index coefficient estimates and gains for all of the characters evaluated. However, lower gains for number of grains per spike and grain yield were obtained, when compared to those obtained with selection for grain yield. |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47571999000100021 |
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| Rêgo,Elizanilda R. do; Finger,Fernando L.; Casali,Vicente W.D.; Cardoso,Antônio A.. |
| A naturally occurring yellow tomato fruit mutant cv. Santa Clara was reciprocally crossed with the red wild type, after which F1 plants were self pollinated or backcrossed with both parents. Plants from F1 generations produced all fruits with a homogeneous deep red color when ripe. F2 plants showed a 3:1 red:yellow segregation of fruit color, and 100% red when backcrossed with red wild type or 1:1 red:yellow segregation in backcrosses with the yellow mutant; hence, yellow fruit color was determined by a recessive allele. Based on reciprocal crosses, fruit color is unlikely to be determined by maternal genes. Accumulation of lycopene dropped by 99.3% and<FONT FACE="Symbol"> b</font>-carotene by 77% in ripe yellow fruits, compared to the red wild... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47571999000100019 |
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| Jordana,J.; Manteca,X.; Ribo,O.. |
| Relationships among 25 dog breeds, classified a priori by their respective ancestral trunks, were studied using data from 29 morphological and 13 behavioral characteristics. Although a certain correlation was found between both types of traits (r = 0.13; P < 0.05), this relationship was not manifested, regarding the level of racial classification, in the obtained dendrograms. The relationships between breeds obtained from morphological data were more congruent than those obtained from behavioral data when compared with phylogenies from other sources of information (mainly electrophoretic analysis). This indicates that the morphological characters could give more and better complementary information than the behavioral ones in the reconstruction of... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47571999000100011 |
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| Castanheira,Ana L.M.; Santos,João B. dos; Ferreira,Daniel F.; Melo,Leonardo C.. |
| RAPD markers were identified close to common bean alleles responsible for resistance to the fungus Colletotrichum lindemuthianum and may be useful in selecting plants resistant to this pathogen. DNA from F2 plants of the crosses Carioca 300V x P45, Carioca 300V x Ouro and P24 x Ouro was amplified by RAPD. Line P45 has the Co.4 allele for resistance, and the Ouro cultivar has the Co.5 allele. The primer OPC08 amplified a DNA fragment of about 1059 bp linked to the Co.4 allele. The recombination frequency was 0.133 (SE = 0.039; 95% CI = 0.056-0.211). Using the primer OPF10 a DNA fragment of about 912 bp was amplified and found to be associated with the Co.5 allele. The recombination frequency was 0.115 (SE = 0.038; 95% CI = 0.041-0.189). A second marker... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47571999000400017 |
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| Rodrigues,Rosana; Leal,Nilton Rocha; Pereira,Messias Gonzaga; Lam-Sánchez,Alfredo. |
| Many diseases limit dry bean and snap bean yields. Common bacterial blight (CBB), caused by Xanthomonas axonopodis pv. phaseoli, is one of the most serious bacterial diseases in dry bean and snap bean that cause crop losses. Since there is no satisfactory chemical control, the use of resistant cultivars is an important control measure. Genetic studies of resistance are important for choosing appropriate breeding methods. Combining ability was determined for disease resistance in three snap bean genotypes (Alessa, Hab 52 and Hab 198) and two dry bean genotypes (Bac-6 and A-794). Plants were inoculated with highly pathogenic isolate CNF 15, using a razor blade procedure in leaves and needle punctures in pods. They were evaluated 7 days after inoculation.... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47571999000400018 |
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| Seoane,A.I.; Dulout,F.N.. |
| There is increasing evidence that aneuploidy during mitosis may be a factor in the etiology of somatic malignancy. The analysis of alterations in anaphase-telophase of mitosis is a useful test for evaluating the aneuploidogenic and clastogenic ability of chemicals. Several metals have been found to be carcinogenic to humans and animals. However, the underlying mechanisms remain unclear. In the present study the aneugenic and clastogenic abilities of cadmium sulfate, potassium dichromate and nickel chloride were analyzed using the anaphase-telophase test. Chinese hamster ovary (CHO) cells cultured for two cycles were treated with the desired compound for 8 h before cell harvesting. The frequency of cells with chromatin bridges, lagging chromosomes and... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47571999000400015 |
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| Cotias-de-Oliveira,Ana Lúcia Pires; Guedes,Maria Lenise Silva; Barreto,Ervene Cerqueira. |
| Chromosome numbers for four species of Anthurium and four species of Philodendron from Bahia, Brazil, were determined. New counts 2n = 30 for A. longipes and A. affine, 2n = 32 for P. pedatum and 2n = 34 P. blanchetianum and P. pachyphyllum represent the first reports for these species. The 2n = 32 found for P. imbe and 2n = 90 for A. bellum differ from earlier reports, whereas 2n = 30 and 60 for A. pentaphyllum var. pentaphyllum confirms previous counts. A. affine had one to four B-chromosomes. We suggest secondary base numbers x = 15 for Anthurium and x = 16, 17 and 18 for Philodendron, produced by hybridizations and duplications involving the primary base numbers x = 7, 8 and 9. |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47571999000200018 |
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| Gonçalves,Paulo de Souza; Furtado,Edson Luiz; Bataglia,Ondino Cleante; Ortolani,Altino Aldo; May,André; Belletti,Giselle Olmos. |
| Rubber tree [Hevea brasiliensis (Willd. ex Adr. de Juss.) Muell-Arg] anthracnose panel canker disease resistance, caused by Colletotrichum gloeosporioides (Penz.) Sacc., and growth and yield characters were assessed at three years old in the nursery, in 18 half-sib progenies. There were highly significant (P < 0.01) genetic differences among progenies for most characters. The genetic component of variance accounted for 3.37, 6.07, 12.74, 12.13, 19.82 and 3.58% of the phenotypic variance for anthracnose-infected area, anthracnose lesion stripe length, yield, girth, virgin bark thickness and total number of latex vessel rings, respectively. Narrow-sense heritability estimates for the above characters were 13.45, 24.30, 50.97, 48.52, 79.30 and 14.30%,... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47571999000400020 |
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| Sabri,Hani M.; Wilson,Henry R.; Harms,Robert H.; Wilcox,Charles J.. |
| Estimates of heritability and phenotypic and genetic correlations between egg number, weight, specific gravity, mass, and estimated shell weight were obtained, along with phenotypic and genetic correlations of specific gravity and weight with body weight, weight change, metabolizable energy intake, residual feed consumption, and weight and age at sexual maturity. Data were from 350 White Leghorn hens by 50 sires and 175 dams. Heritabilities of the egg traits ranged from 0.20 to 0.55, increasing with age of bird from 26 to 54 weeks of age. Their standard errors ranged from 0.07 (all data) to 0.17 (26 to 29 weeks). Phenotypic correlations ranged from 0.80 to -0.13, and genetic correlations from 0.91 to -0.27, depending on egg trait. The highest phenotypic... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47571999000200008 |
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| Guerra,Marcelo. |
| A staining mixture of hematoxylin-iron alum combined with a strong hydrochloric hydrolysis was successfully applied for chromosome observation of several kinds of plants and some animals. Slightly different procedures were developed for different materials and objectives. For plant cells, the most important technical aspect was the use of 5 N HCl hydrolysis, which resulted in a very transparent cytoplasm, combined with an intense, specific hematoxylin stain. This technique is recommended for cytogenetical analysis in general, and it is especially indicated for practical classes, due to its simplicity and high reproducibility of results. Moreover, the deep contrast observed makes this technique very useful for sequential staining of cells previously... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47571999000100016 |
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| Dornelles,C.L.; Callegari-Jacques,S.M.; Robinson,W.M.; Weimer,T.A.; Franco,M.H.L.P.; Hickmann,A.C.; Geiger,C.J.; Salzano,F.M.. |
| A total of 2,708 individuals from the European-derived population of Rio Grande do Sul, divided into seven mesoregions, and of 226 individuals of similar origin from Santa Catarina were studied. Seventeen protein genetic systems, as well as grandparents' nationalities, individuals' surnames, and interethnic admixture were investigated. The alleles which presented the highest and lowest differences were GLO1*2 (16%) and PGD*A (2%), respectively, but in general no significant genetic differences were found among mesoregions. The values observed were generally those expected for individuals of European descent, with the largest difference being a lower prevalence (34-39%) of P*1. Significant heterogeneity among mesoregions was observed for the other variables... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47571999000200003 |
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| Savoldi-Barbosa,Marcela; Sakamoto-Hojo,Elza T.; Takahashi,Catarina S.. |
| Experiments with novobiocin (NB) post-treatment were performed to verify its effect on the frequencies of micronuclei (MN) and chromosomal aberrations (CA) induced by <FONT FACE="Symbol">g</font>-irradiation (0.75, 1.5 and 3.0 Gy) in human lymphocytes at G0-phase. The frequencies of MN significantly decreased by 44 and 50%, for the treatment with NB 50 µg/ml (30-min pulse) after radiation doses of 1.5 and 3.0 Gy, respectively. However, CA frequencies were not significantly affected. No significant effect on CA was observed when lymphocyte cultures were exposed to a single dose of 2.0 Gy at the G0-phase and posttreated with 25 µg/ml NB for three hours either immediately after irradiation (G0-phase) or after 24 h (S-phase). The significant... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47571999000200014 |
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| Sheppard,Walter S.; Rinderer,Thomas E.; Garnery,Lionel; Shimanuki,Hachiro. |
| Within the past 40 years, Africanized honey bees spread from Brazil and now occupy most areas habitable by the species Apis mellifera, from Argentina to the southwestern United States. The primary genetic source for Africanized honey bees is believed to be the sub-Saharan honey bee subspecies A. m. scutellata. Mitochondrial markers common in A. m. scutellata have been used to classify Africanized honey bees in population genetic and physiological studies. Assessment of composite mitochondrial haplotypes from Africanized honey bees, using 4 base recognizing restriction enzymes and COI-COII intergenic spacer length polymorphism, provided evidence for a more diverse mitochondrial heritage. Over 25% of the "African" mtDNA found in Africanized populations in... |
| Tipo: Info:eu-repo/semantics/other |
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| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47571999000100015 |
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| Pena,Sérgio D.J.; Sturzeneker,Rosane. |
| We have developed a non-isotopic technique based on methylation-specific PCR (MSP) of the FMR1 promoter for the identification of fragile X full mutations among men. DNA samples were first treated with sodium bisulfite to convert unmethylated, but not methylated, cytosines to uracil, followed by PCR amplification with oligonucleotide primers specific for methylated versus unmethylated DNA. We designed two primer pairs: one produced a 142-bp fragment from the bisulfite-treated methylated CpG island, while the other generated an 84-bp product from the treated non-methylated promoter. In normal males only the 84-bp fragment was seen, while the diagnosis of FRAXA was doubly indicated by the appearance of a 142-bp product together with absence or weak... |
| Tipo: Info:eu-repo/semantics/other |
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| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47571999000200005 |
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| Lumsden,Joanne M.; Lord,Eric A.; Hirst,Karen L.; Dixon,Michael J.; Montgomery,Grant W.. |
| Genes from sheep chromosome 6 map to human chromosome 4 in the region extending from 4p16 to 4q26. However, there is an inversion of gene order in the central portion of the chromosome with one breakpoint close to secreted phosphoprotein 1 (SPP1). Genes for SPP1, integrin-binding sialoprotein (IBSP) and dentin-specific acidic phosphoprotein (DMP1) are located close together in a YAC contig in the human. RFLP markers were developed for DMP1 and IBSP in sheep and located on the sheep linkage map to further define the breakpoint region. There were no recombinants between SPP1 and IBSP indicating that these loci are close together in sheep, as in humans. DMP1 was located approximately 80 cM from SPP1 in sheep, 7 cM from the microsatellite BMC4203. In the human... |
| Tipo: Info:eu-repo/semantics/article |
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| Ano: 1999 |
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-47571999000100007 |
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| Registros recuperados: 6.820 | |
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