Nonpreference of the lace bug Leptopharsa heveae Drake & Poor (Heteroptera: Tingidae) for rubber tree clones

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Comparação entre alguns critérios de seleção para crescimento na raça Nelore

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Peso adulto de matrizes em rebanhos de seleção da raça Nelore no Brasil

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Seleção de métodos para avaliação do cobre disponível nos solos

Fez-se um estudo de seleção de métodos para cobre disponível, empregando-se trinta solos coletados na região de Jaboticabal, SP. Os solos utilizados pertencem aos seguintes grandes grupos: Solos Podzolizados de Lins e Marília, variação Lins e variação Marília, Latossolo Vermelho-Escuro fase arenosa, Latossolo Roxo, e Terra Roxa Estruturada. O cobre dos solos foi extraído através das seguintes soluções extratoras: CaCl2 0,5 M; Mg02 2,0 N; CH3COONH4 1,0 N1 pH 6,0 e pH 4,8; HCl 0,05 N e O,1 N; H2SO4 0,05 N; DTPA 0,005 M pH 7,3 e pH 6,0; EDTA 0,01 M + (NH4)2CO3 1,0 MpH 8,6; EDTA 0,02 M + CH3C0011 0,5 M + CH3COONH4 0,5 M pH 4,65 (AAAc-EDTA); e Na2EDTA 1,0%. Foi realizado ensaio em casa de vegetação, e o milho (Zea mays L.) foi empregado como planta teste. Excluindo-se o extrator CaCl2 0,5 M, todos os demais apresentaram coeficientes de correlação entre cobre extraído do solo e o absorvido pelo milho, significativos e próximos uns dos outros. Assim, com base também em parâmetros como o coeficiente de variação, o coeficiente angular e a praticidade do método, pode-se indicar um dos seguintes extratores para a avaliação do cobre disponível dos solos: DTPA 0,005 M pH 7,3, HCl 0,1 N e Na2EDTA 1,0%.

Estimativas de herdabilidade e proposição de índices de seleção em Hereford no Rio Grande do Sul

A total of 8,064 records from weaning weights and conformation scores traits of calves nearly seven month-old were studied. The study included animals from 22 herds from state of Rio Grande do Sul, borned from 1973 to 1985 which were raised on pastures. The weaning weight adjusted to 205-day weight and fat deposition and the relation size-length of body were scored subjectively in a scale from zero to ten. The dates 205-day weight, fat deposition and relation size-length of body were 137.00 +/- .20 kg; 6.38 +/- 01 and 6.77 +/- 01 grades, respectively. The heritability estimates were .25 +/- .03, .38 +/- 04 and .37 +/- 04, respectively. The selection index was more efficient than direct phenotypic selection and this study also indicates that general selection index is not adequated to use it in all farms, and it is not necessary to have accurate economic values. The most important parameters to get good selection are reliable estimates of genetic and phenotypic variances and covariances.

Acerola's clones of industrial interest

In order to know which clone of acerola is better for acerola industrialization, we studied the pectin methylesterase (PME) specific activity, pectin content and vitamin C content in five different clones of acerola. The pectin yield varied from 1.37 to 2.99% and the highest content of pectin occurred in clones 3 and 5. Ascorbic acid varied significantly from 1157.5 to 1735.5 mg/100 g of pulp in the five clones. The highest content of vitamin C occurred in clone 4. The PME specific activity varied from 0.79 to 2.92 units g(-1)/g of pulp and the highest values occurred in clone 2. We also studied the optimum temperature and the optimum pH of this enzyme. Clones 1, 2, 4 and 5 showed optimum temperature at 90C. Clone 3 showed practically the same specific activity at all temperatures studied. Clones 1 and 4 showed an optimum pH of 9.0 and clone numbers 2, 3 and 5 showed a pH optimum at 8.5.

Seleção de extratores químicos para avaliação da disponibilidade de zinco em solos do estado de São Paulo

The purpose of this study was to evaluate methods for predicting availability of Zn in soils. Surface soil samples representing Podzolized soils from Lins and Marilia var. Marilia and var. Lins, medium texture Dark-Red Latosol, Dusky-Red Latosol and Terra Roxa Estruturada, were gathered from fields in Jaboticabal, SP, Brazil. Com was used as indicator plant in a greenhouse experiment. Availability of Zn was determined with: 0.5 M CaCl2, 2.0 N MgCl2, N CH3COONH4 (pH 6.0 and 4.8), 0.05 and 0.1 N HCl, 0.05 N H2SO4, 0.005 M DTPA (pH 7.3 and 6.0), 1.0% Na2-EDTA, 0.01 M EDTA + 1.0 M (NH4)2CO3 (pH 8.6) and 0.02 M EDTA + 0.5 M CH3COOH + 0.5 M CH3COONH4. By using the simple correlation coefficients (Zn extracted from soils x absorbed by plants it can be concluded that the complexant agents and acid solutions showed to be efficient. The salt solutions showed low extraction capacity, low correlation coefficients and less accuracy. By considering aspects as accuracy and easy management DTPA pH 7,3 and Na2-EDTA can be indicated as the most apropriates (r values, respectively, 0.873** and 0.868** and V.C. 7.52% and 7.98%).

Acclimation to short-term low temperatures in two Eucalyptus globulus clones with contrasting drought resistance

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Multiple cytogenetic clones in a basal cell carcinoma

Chromosome analysis of short-term culture of a basal cell carcinoma showed five clonal chromosome abnormalities, t(9;14)(q12 or q13;p11), del(1)(q23 or q25), trisomy 5, trisomy 7, and monosomy X. In addition, several nonclonal structural and numerical changes were seen in the tumor cells.

Estimativas de parâmetros genéticos e proposição de critérios de seleção para pesos na raça Canchim

The objectives of this study were to obtain heritability and genetic, phenotypic and environmental correlation estimates for birth (B), weaning (WW), yearling (YW) and 18 - (EW) and 24 - month (TW) weights, and to propose selection criteria for body weight in Canchim cattle. The data were analyzed by the least-squares method with models that included the fixed effects of herd, year and month of birth, sex of calf and age of cow at calving, and the random effects of sire within herd. The heritability estimates obtained were equal to 0.36 0.06 (BW), 0.47 0.06 (WW), 0.53 0.07 (YW), 0.54 0.08 (EW) and 0.27 0.06 (TW). The genetic correlations were equal to 0.51 (BW and WW), 0.36 (BW and YW), 0.14 (BW and EW), 0.00 (BW and TW), 0.92 (WW and YW), 0.77 (WW and EW), 0.75 (WW and TW), 0.94 (YW and EW), 0.86 (YW and TW) and 0.85 (EW and TW). The phenotypic correlations ranged from 0.19 to 0.72, and the environmental correlations from 0.11 to 0.61. The results showed that, in general, mass selection for weight will result in genetic progress, selection for weight at any age will result in correlated changes at other ages, and EW and TW are good selection criteria for increasing weight in the Canchim breed.

Efeito da seleção quanto ao peso corporal nas características reprodutivas em linhagens de frangos de corte

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Efeitos da Seleção para Peso Pós-desmame sobre Medidas Corporais e Perímetro Escrotal de Machos Nelore de Sertãozinho (SP)

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Modelo de otimização para seleção de árvores matrizes de Eucalyptus grandis

Individual data of basic density and volume of wood, pulp kappa number, soluble lignin, cost of pulping process as well as gravimetric gross yield of pulping process were used from 64 trees of Eucalyptus grandis W. Hill ex Maiden from a commercial population at Lençóis Paulista, SP. The Eucalyptus grandis's seeds were originally from a Seed Production Area (SPA) of Duratex S/A at Botucatu, SP. Obtained data were quantified considering objective of maximization no-bleaching pulp and volume and mass wood restriction, mass of residual and soluble lignin, planted area and pulping process cost. it has also been aimed a selection method for matrix trees through mathematical programming techniques. Obtained strategy maximized the economical result, selected matrix trees and followed all limits of technological and organizing productivities imposed by the company. It also aimed the production of no-bleaching pulp within the planned time.

Drought tolerance of two field-grown clones of Coffea canephora

We compared tolerance to soil drought of two field-grown clones of Coffea canephora (clone 46, drought-sensitive; and clone 120, drought-tolerant). Under irrigation, there were no marked differences between the clones in water relation parameters, gas exchange and total leaf area. Under rainfed conditions, clone 46 showed osmotic adjustment and increased tissue rigidity. These adjustments, however, were incapable of preventing substantial decreases in xylem pressure potential. By contrast, clone 120 did not exhibit osmotic adjustment, but was able to increase tissue elasticity and to maintain xylem pressure potentials to a greater extent than clone 46 (despite having twice the total leaf area of this clone). Stomatal conductance was lowered by drought in clone 120 but not in clone 46. Carbon assimilation per unit leaf area in both clones remained unaffected under stress. Long-term water use efficiency (WUE), as estimated through carbon isotope discrimination, was consistently greater in clone 120 than in clone 46. Because of these traits, clone 120 was better able to postpone dehydration and to maintain whole-tree photosynthesis. It is proposed that these features should decisively contribute to buffer its productivity in drought-prone areas. © 2002 Elsevier Science Ireland Ltd. All rights reserved.

Thermogravimetric studies of the decomposition kinetics of four different Hevea rubber clones using Ozawa's approach

Thermal degradation of natural rubber extracted from four different rubber clones of the Hevea brasiliensis species was investigated by thermogravimetry using Ozawa's approach to assess the kinetic parameters of the decomposition process. The results are discussed in terms of the order of reaction, kinetic parameters such as activation energy as a function of conversion degree, and thermal stability for each of the clones.