Contributions of plant breeding in Brazil: progress and perspectives

Agribusiness is fundamental for the Brazilian economy. This has become possible due to the use of science and technology in agriculture in the last 35 years. Among the technologies, the use of improved cultivars stands out. This article presents the situation of the species grown in the country in recent years and the contribution of genetic plant breeding to the performance of these species. Challenges multiplied because of populational growth associated with the ever-growing concern of society with the environment. Breeders of the present and future must base plant selection in the field on new technologies so that it is possible to meet demand

Nível de hemoglobina entre idosos e sua associação com indicadores do estado nutricional e uso de serviços de saúde: Projeto Bambuí

O objetivo deste estudo foi descrever a prevalência de anemia e avaliar a associação de nível de hemoglobina (Hb) com indicadores do estado nutricional e uso de serviços de saúde em uma população idosa (≥ 60 anos). Dos 1.742 idosos participantes da linha de base da coorte de Bambuí, Minas Gerais, Brasil, foram incluídos 1.441 (82,7%). A variável dependente foi o nível de Hb e as independentes foram número de hospitalizações e visitas ao médico nos 12 meses precedentes à entrevista, índice de massa corporal (IMC) e albumina sérica. Foi realizada regressão linear multivariada estratificada por sexo e ajustada por fatores de confusão. A prevalência de anemia foi baixa na população (4,5%), sem diferenças entre sexos e significativamente maior em idosos mais velhos (10,2%). Baixos níveis de Hb foram associados ao maior número de consultas médicas e a menores valores de albumina sérica e IMC em ambos os sexos. O estudo sugere um ciclo complexo entre baixos níveis de Hb, desnutrição e atendimento médico, o que deve ser considerado na estruturação de programas de saúde para idosos.This study aimed to describe the prevalence of anemia and to evaluate the association between hemoglobin (Hb) level and indicators of nutritional status and health services utilization in an elderly population (≥ 60 years). Of the 1,742 older adults in the baseline of the Bambuí cohort, 1,441 (82.7%) were included. The dependent variable was Hb level, and the independent variables were number of hospitalizations and physician visits in the previous 12 months, body mass index (BMI), and serum albumin. Multivariate linear regression was performed, stratified by gender and adjusted for confounding factors. Prevalence of anemia was low (4.5%), with no difference by gender, and higher in the oldest old (10.2%). Low Hb level was associated with more physician visits and lower serum albumin and BMI in both men and women, suggesting a complex cycle between low Hb level, malnutrition, and medical care that should be considered when structuring health programs for the elderly

Genetic variability in progenies of Eucalyptus dunnii Maiden for resistance to Puccinia psidii

This study investigated the genetic variability in progenies of Eucalyptus dunnii Maiden for resistance against rust (Puccinia psidii). Field experiments were installed in two regions with different soil-climatic conditions. Open-pollinated progenies were established in a randomized complete block design. Sixty and 48 progenies were evaluated under field conditions at two sites, respectively, with six replications and eight trees per plot. In another experiment in a controlled environment, 53 progenies were evaluated in randomized blocks with six replications and nine plants per plot. The following traits were evaluated: plant height, severity of pest attack and the most susceptible stage to the leaf disease. The genetic variability for rust resistance in the E. dunnii population under study was high, with a genetic coefficient of variation of 36.07%; 7% of the evaluated progenies were rust-resistant. It indicates a high potential for selection and breeding of the species

Litterfall and Nutrient Input in a Degraded Area

ABSTRACT This study aimed to test the effects of fertilization with organic compost from industrial production of pulp on the litterfall and nutrient input of monospecific plantations in a loan area. The treatments consisted of three doses of the organic compost D10, D15 and D20 (10, 15 and 20 Mg ha-1, respectively), mineral conventional fertilization (DAM) and no fertilization (D0) in land plots (N = 4/treatment/species; 15 x 12 m). Litterfall was monthly collected by two traps (0.72 m2/plot) and sorted out into leaves, twigs, seeds, flowers, fruits and others. We determined the input of nitrogen, phosphorous and potassium. There were no differences among the treatments and between species in terms of total annual litterfall. The higher nutrient input was obtained by DAM, followed by D10, in both plantations. The annual nutrient input was higher for the litterfall on the E. urograndis plantation

LEAF TOTAL NITROGEN CONCENTRATION AS AN INDICATOR OF NITROGEN STATUS FOR PLANTLETS AND YOUNG PLANTS OF EUCALYPTUS CLONES

The use of leaf total nitrogen concentration as an indicator for nutritional diagnosis has some limitations. The objective of this study was to determine the reliability of total N concentration as an indicator of N status for eucalyptus clones, and to compare it with alternative indicators. A greenhouse experiment was carried out in a randomized complete block design in a 2 × 6 factorial arrangement with plantlets of two eucalyptus clones (140 days old) and six levels of N in the nutrient solution. In addition, a field experiment was carried out in a completely randomized design in a 2 × 2 × 2 × 3 factorial arrangement, consisting of two seasons, two regions, two young clones (approximately two years old), and three positions of crown leaf sampling. The field areas (regions) had contrasting soil physical and chemical properties, and their soil contents for total N, NH+4-N, and NO−3-N were determined in five soil layers, up to a depth of 1.0 m. We evaluated the following indicators of plant N status in roots and leaves: contents of total N, NH+4-N, NO−3-N, and chlorophyll; N/P ratio; and chlorophyll meter readings on the leaves. Ammonium (root) and NO−3-N (root and leaf) efficiently predicted N requirements for eucalyptus plantlets in the greenhouse. Similarly, leaf N/P, chlorophyll values, and chlorophyll meter readings provided good results in the greenhouse. However, leaf N/P did not reflect the soil N status, and the use of the chlorophyll meter could not be generalized for different genotypes. Leaf total N concentration is not an ideal indicator, but it and the chlorophyll levels best represent the soil N status for young eucalyptus clones under field conditions