Contribution of graduate programs in plant breeding to the education of plant breeders in Brazil

The success of agribusiness in Brazil in recent decades is unquestionable. Although the country has always had favorable conditions for agriculture (land, water and climate), this success has only come about recently, due to scientific research, which has resulted in considerable increases in yield and in improvement of product quality, as well as making the occupation of new agricultural frontiers possible. A decisive factor for development of agriculture in the country was the creation of EMBRAPA in 1973, which, in a few years, led to considerable demand for researchers with training in graduate programs. Among them are plant breeders, who came to exercise their activity throughout the country and in all ecosystems. The training of plant breeders was only possible because, as from the middle of the 1960s, the country began a wide-ranging education program, with the creation of several graduate programs in genetics and plant breeding.

Contribution and perspectives of quantitative genetics to plant breeding in Brazil

The purpose of this article is to show how quantitative genetics has contributed to the huge genetic progress obtained in plant breeding in Brazil in the last forty years. The information obtained through quantitative genetics has given Brazilian breeders the possibility of responding to innumerable questions in their work in a much more informative way, such as the use or not of hybrid cultivars, which segregating population to use, which breeding method to employ, alternatives for improving the efficiency of selection programs, and how to handle the data of progeny and/or cultivars evaluations to identify the most stable ones and thus improve recommendations.

Experimental hyperprolinemia induces mild oxidative stress, metabolic changes, and tissue adaptation in rat liver

The present study investigated the effects of chronic hyperprolinemia on oxidative and metabolic status in liver and serum of rats. Wistar rats received daily subcutaneous injections of proline from their 6th to 28th day of life. Twelve hours after the last injection the rats were sacrificed and liver and serum were collected. Results showed that hyperprolinemia induced a significant reduction in total antioxidant potential and thiobarbituric acid-reactive substances. The activities of the antioxidant enzymes catalase and superoxide dismutase were significantly increased after chronic proline administration, while glutathione (GSH) peroxidase activity, dichlorofluorescin oxidation, GSH, sulfhydryl, and carbonyl content remained unaltered. Histological analyses of the liver revealed that proline treatment induced changes of the hepatic microarchitecture and increased the number of inflammatory cells and the glycogen content. Biochemical determination also demonstrated an increase in glycogen concentration, as well as a higher synthesis of glycogen in liver of hyperprolinemic rats. Regarding to hepatic metabolism, it was observed an increase on glucose oxidation and a decrease on lipid synthesis from glucose. However, hepatic lipid content and serum glucose levels were not changed. Proline administration did not alter the aminotransferases activities and serum markers of hepatic injury. Our findings suggest that hyperprolinemia alters the liver homeostasis possibly by induction of a mild degree of oxidative stress and metabolic changes. The hepatic alterations caused by proline probably do not implicate in substantial hepatic tissue damage, but rather demonstrate a process of adaptation of this tissue to oxidative stress. However, the biological significance of these findings requires additional investigation. J. Cell. Biochem. 113: 174183, 2012. (C) 2011 Wiley Periodicals, Inc.

Strategies in identifying individuals in a segregant population of common bean and implications of genotype x environment interaction in the success of selection

The objective of this study was to compare the BLUP selection method with different selection strategies in F-2:4 and assess the efficiency of this method on the early choice of the best common bean (Phaseolus vulgaris) lines. Fifty-one F-2:4 progenies were produced from a cross between the CVIII8511 x RP-26 lines. A randomized block design was used with 20 replications and one-plant field plots. Character data on plant architecture and grain yield were obtained and then the sum of the standardized variables was estimated for simultaneous selection of both traits. Analysis was carried out by mixed models (BLUP) and the least squares method to compare different selection strategies, like mass selection, stratified mass selection and between and within progeny selection. The progenies selected by BLUP were assessed in advanced generations, always selecting the greatest and smallest sum of the standardized variables. Analyses by the least squares method and BLUP procedure ranked the progenies in the same way. The coincidence of the individuals identified by BLUP and between and within progeny selection was high and of the greatest magnitude when BLUP was compared with mass selection. Although BLUP is the best estimator of genotypic value, its efficiency in the response to long term selection is not different from any of the other methods, because it is also unable to predict the future effect of the progenies x environments interaction. It was inferred that selection success will always depend on the most accurate possible progeny assessment and using alternatives to reduce the progenies x environments interaction effect.

Selection and Use Recommendation in Hybrids of Ornamental Banana

The ornamental market is dynamic and demands constant novelties. The use of fruit crops as ornamental plants can be an interesting alternative with very differentiated and original products. The banana germplasm bank at Embrapa Cassava and Fruits has been primarily used in the breeding program for generating new cultivars as food. To diversify and expand the use of this collection, accessions with ornamental potential have been selected to obtain new hybrids. This work was aimed at characterizing the progeny of ornamental Musa L. spp. by grouping the hybrids according to the following uses: landscape plants, potted plants, cut flower, or minifruits. Forty-two hybrids were evaluated with 14 quantitative and 12 qualitative descriptors in three production cycles. In addition, assays for resistance to black and yellow Sigatoka and to Fusarium wilt were performed. Variability was observed for all the characteristics evaluated within progenies, especially with regard to leaf color, fruit, peduncle, rachis, and heart. All evaluated hybrids were resistant to yellow Sigatoka and to Fusarium wilt and were resistant or showed reduced symptoms of susceptibility to black Sigatoka. Most hybrids (82%) presented reduced plant height. After clustering by use category, the hybrids RM 09, RM 38, RM 37, and RM 33 were selected and recommended to be used as cut flowers, minifruits, or landscaping plants.

PHOSPHITE AS PHOSPHORUS SOURCE TO GRAIN YIELD OF COMMON BEAN PLANTS GROWN IN SOILS UNDER LOW OR ADEQUATE PHOSPHATE AVAILABILITY

The effects of foliar and soil applied phosphite on grain yield in common bean (Phaseolus vulgaris L.) grown in a weathered soil under low and adequate phosphate availability were evaluated. In the first experiment, treatments were composed of a 2 x 7 + 2 factorial scheme, with 2 soil P levels supplied as phosphate (40 e 200 mg P dm(-3) soil), 7 soil P levels supplied as phosphite (0-100 mg P dm(-3) soil), and 2 additional treatments (without P supply in soil, and all P supplied as phosphite). In the second experiment, treatments were composed of a 2 x 3 x 2 factorial scheme, with 2 soil phosphate levels (40 e 200 mg P dm(-3) soil), combined with 3 nutrient sources applied via foliar sprays (potassium phosphite, potassium phosphate, and potassium chloride as a control), and 2 foliar application numbers (single and two application). Additional treatments showed that phosphite is not P source for common bean nutrition. Phosphite supply in soil increased the P content in shoot (at full physiological maturity stage) and grains, but at the same time considerably decreased grain yield, regardless of the soil phosphate availability. Foliar sprays of phosphite decreased grain yield in plants grown under low soil phosphate availability, but no effect was observed in plants grown under adequate soil phosphate availability. In general, foliar sprays of phosphate did not satisfactorily improve grain yield of the common bean plants grown under low soil phosphate availability.

Evolution of extrafloral nectaries: adaptive process and selective regime changes from forest to savanna

Much effort has been devoted to understanding the function of extrafloral nectaries (EFNs) for antplantherbivore interactions. However, the pattern of evolution of such structures throughout the history of plant lineages remains unexplored. In this study, we used empirical knowledge on plant defences mediated by ants as a theoretical framework to test specific hypotheses about the adaptive role of EFNs during plant evolution. Emphasis was given to different processes (neutral or adaptive) and factors (habitat change and trade-offs with new trichomes) that may have affected the evolution of antplant associations. We measured seven EFN quantitative traits in all 105 species included in a well-supported phylogeny of the tribe Bignonieae (Bignoniaceae) and collected field data on antEFN interactions in 32 species. We identified a positive association between ant visitation (a surrogate of ant guarding) and the abundance of EFNs in vegetative plant parts and rejected the hypothesis of phylogenetic conservatism of EFNs, with most traits presenting K-values < 1. Modelling the evolution of EFN traits using maximum likelihood approaches further suggested adaptive evolution, with static-optimum models showing a better fit than purely drift models. In addition, the abundance of EFNs was associated with habitat shifts (with a decrease in the abundance of EFNs from forest to savannas), and a potential trade-off was detected between the abundance of EFNs and estipitate glandular trichomes (i.e. trichomes with sticky secretion). These evolutionary associations suggest divergent selection between species as well as explains K-values < 1. Experimental studies with multiple lineages of forest and savanna taxa may improve our understanding of the role of nectaries in plants. Overall, our results suggest that the evolution of EFNs was likely associated with the adaptive process which probably played an important role in the diversification of this plant group.

On the implementation of good manufacturing practices in a small processing unity of mozzarella cheese in Brazil

This study reports the implementation of GMPs in a mozzarella cheese processing plant. The mozzarella cheese manufacturing unit is located in the Southwestern region of the state of Parana, Brazil, and processes 20,000 L of milk daily. The implementation of GMP took place with the creation of a multi-disciplinary team and it was carried out in four steps: diagnosis, report of the diagnosis and road map, corrective measures and follow-up of GMP implementation. The effectiveness of actions taken and GMP implementation was compared by the total percentages of non-conformities and conformities before and after implementation of GMR Microbiological indicators were also used to assess the implementation of GMP in the mozzarella cheese processing facility. Results showed that the average percentage of conformity after the implementation of GMP was significant increased to 66%, while before it was 32% (p < 0.05). The populations of aerobic microorganisms and total coliforms in equipment were significantly reduced (p < 0.05) after the implementation of GMP, as well as the populations of total coliforms in the hands of food handlers (p < 0.05). In conclusion, GMP implementation changed the overall organization of the cheese processing unity, as well as managers and food handlers' behavior and knowledge on the quality and safety of products manufactured. (C) 2011 Elsevier Ltd. All rights reserved.

Further investigating the determination of phosphorus in plants by INAA using bremsstrahlung measurement

Phosphorus is an essential element for plants and animals, playing a fundamental role in the production of biochemical energy. Despite its relevance, phosphorus is not commonly determined by instrumental neutron activation analysis (INAA), because (32)P does not emit gamma-rays in its decay. There are alternative methods for the determination of phosphorus by INAA, such as the use of beta counting or the measurement of bremsstrahlung originated from the high energy beta particle from (32)P. Here the determination of phosphorus in plant materials by measuring the bremsstrahlung production was further investigated, to optimize an analytical protocol for minimizing interferences and overcoming the poor specificity. Eight certified reference materials of plant matrices with phosphorus ranging between 171 and 5,180 mg kg(-1) were irradiated at a thermal neutron flux of 9.5 x 10(12) cm(-2) s(-1) and measured with a HPGe detector at decay times varying from 7 to 60 days. Phosphorus solutions added to a certified reference material at three levels were used for calibration. Counts accumulated in the baseline at four different regions of the gamma-ray spectra were tested for the determination of phosphorus, with better results for the 100 keV region. The Compton scattering contribution in the selected range was discounted using an experimental peak-to-Compton factor and the net areas of all peaks in the spectra with energies higher than 218 keV, i.e. Compton edge above 100 keV. Amongst the interferences investigated, the production of (32)P from sulfur, and the contribution of Compton scattering should be considered for producing good results.