J. C. Albrecht

Estimates of genetic parameters for physic nut traits based in the germplasm two years evaluation

In spite of increasingly widespread interest in planting physic nut, breeding efforts are still in its infancy. In that context, an important resource recently established aiming future breeding efforts was the assembly of a germplasm bank with near 200 accessions. The objective of this study was to estimate genetic parameters, repeatibility coefficients and genetic correlation between seven traits, measured in 110 accessions (half sib families) of this germplasm bank in different stages of development. The results show that higher relative values of additive variance were only found for yield and height, and the existence of low environmental variation (either of temporary or permanent nature) among plots within blocks. Given the high repeatibility values found for all traits, on average three measurements are necessary to predict, accurately and efficiently, the true breeding value of an individual. Based on the results of genetic correlations, breeding effort should initially be use track trees with increased stem diameter, elevated number of branches and canopy volume so as to increase the chances of finding an exceptionally highly productive tree.

Production of large volume, strongly magnetized laser-produced plasmas by use of pulsed external magnetic fields

The production of strongly magnetized laser plasmas, of interest for laboratory astrophysics and inertial confinement fusion studies, is presented. This is achieved by coupling a 16 kV pulse-power system. This is achieved by coupling a 16 kV pulse-power system, which generates a magnetic field by means of a split coil, with the ELFIE laser facility at Ecole Polytechnique. In order to influence the plasma dynamics in a significant manner, the system can generate, repetitively and without debris, high amplitude magnetic fields (40 T) in a manner compatible with a high-energy laser environment. A description of the system and preliminary results demonstrating the possibility to magnetically collimate plasma jets are given.

Adaptabilidade e estabilidade de genótipos de trigo irrigado no Cerrado do Brasil Central

O objetivo deste trabalho foi estimar a adaptabilidade e estabilidade de genotipos de trigo irrigado, nas condicoes do Cerrado do Brasil Central. O rendimento de graos de cinco cultivares e nove linhagens de trigo irrigado foram aferidos no ensaio de valor de cultivo e uso. Os ensaios foram conduzidos nos anos de 2005 e 2006, em seis locais em Minas Gerais, tres em Goias e um no Distrito Federal. Os dados de rendimento de graos foram submetidos a analise de variância individual e a analise de variância conjunta, para a estimativa dos parâmetros de adaptabilidade e estabilidade. Verificaram-se diferencas significativas, entre os genotipos, em 14 dos 16 ambientes avaliados. Nenhum dos genotipos avaliados apresentou o comportamento ideal preconizado pelo metodo de Cruz e colaboradores. Destacaram-se a cultivar BRS 264 e a linhagem CPAC 02167, pela superioridade em todas as condicoes do Cerrado do Brasil Central (adaptabilidade geral). Entre os demais genotipos avaliados, destacaram-se as cultivares BRS 207 e EMBRAPA 22, responsivas a melhoria das condicoes ambientais, e as cultivares BRS 254 e EMBRAPA 42, pela adaptabilidade especifica a ambientes desfavoraveis ao cultivo de trigo irrigado.

Desempenho agronômico e ganho genético pela seleção de pinhão‑manso em três regiões do Brasil

The objective of this study was to evaluate the agronomic performance and genetic gain by the selection of half-sib families of physic nut grown in three Brazilian regions. Based on previous phenotypic selection, three progeny tests were performed, in 2008, in the municipalities of Planaltina, DF, Nova Porteirinha, MG, and Pelotas, RS. A randomized complete block design was used, with three replicates, and five plants per plot. Randomly collected seeds from a population without selection were used as control. There was a significant interaction between the effects of genotypes and environments. Estimates of variance components and genetic parameters indicated that it is possible to obtain genetic gains from selection of the best families in the evaluated environments. In each environment, at least one family was selected with a higher performance than the control treatment. Mass selection in the three environments provided 72% of genetic gains. The agronomic performance had a high correlation coefficient between the environments of Planaltina and Nova Porteirinha, which did not occur in Pelotas. Genotype x environment interaction should be considered in the recommendations of physic nut genetic material for different environments.

Genotypic variation of zinc and selenium concentration in grains of Brazilian wheat lines

Exploration of genetic resources for micronutrient concentrations facilitates the breeding of nutrient-dense crops, which is increasingly seen as an additional, sustainable strategy to combat global micronutrient deficiency. In this work, we evaluated genotypic variation in grain nutrient concentrations of 20 Brazil wheat (Triticum aestivum L.) accessions in response to zinc (Zn) and Zn plus selenium (Se) treatment. Zn and Se concentrations in grains exhibited 2- and 1.5-fold difference, respectively, between these wheat accessions. A variation of up to 3-fold enhancement of grain Zn concentration was observed when additionally Zn was supplied, indicating a wide range capacity of the wheat lines in accumulating Zn in grains. Moreover, grain Zn concentration was further enhanced in some lines following supply of Zn plus Se, showing stimulative effect by Se and the feasibility of simultaneous biofortification of Zn and Se in grains of some wheat lines. In addition, Se supply with Zn improved the accumulation of another important micronutrient, iron (Fe), in grains of half of these wheat lines, suggesting a beneficial role of simultaneous biofortification of Zn with Se. The significant diversity in these wheat accessions offers genetic potential for developing cultivars with better ability to accumulate important micronutrients in grains.

Evaluation of germplasm effect on Fe, Zn and Se content in wheat seedlings

Micronutrients are essential for human health and crucial for plant survival. The capacity of food crops in acquiring mineral nutrients affects plant growth and potentially the yield and nutrient content in edible tissues/organs. In this study, we selected 20 wheat (Triticum aestivum L.) accessions and evaluated genotypic variations of the young seedlings in response to iron (Fe), zinc (Zn), and selenium (Se) treatments. Wheat accessions exhibited different growth responses to these minerals and possessed various abilities to accumulate them. Wheat seedlings in general were less tolerable to excess of Fe and benefits from increased levels of Zn supply. They were sensitive to selenite and profited from selenate treatment at low dosages. Limited mineral interactions were observed between Fe or Zn with other nutrients. In contrast, selenate supply enhanced Fe, Zn, sulfur (S), molybdenum (Mo), magnesium (Mg), calcium (Ca) and manganese (Mn) content in wheat seedlings, supporting its beneficial role in promoting plant growth; Selenite supplement reduced Zn, S, Mo, Mg, Ca and Mn levels in the plants, consisting with its detrimental role in inhibiting seedling growth. Based on nutrient accumulation, plant growth, and mineral interaction, a number of accessions such as EMB 38 and BRS 264 appeared to be good lines for breeding wheat cultivars with better plant health and potential to accumulate essential micronutrients in edible grains.

Adaptabilidade e estabilidade de progênies de meios-irmãos de pinhão-manso em diferentes regiões do Brasil

Physic nut (Jatropha curcas L.) breeding programs have intensified in the past five years, locally selecting plants from various Brazilian regions. The objective of this study was to quantify the genotype x environment interaction of the physic nut grain production and the genetic progress obtained with the selection. From Half-sib progenies selected by Embrapa and EPAMIG, in 2008, three progeny trials were installed in the cities of Planaltina-DF, Nova Porteirinha-MG and Pelotas-RS, using a randomized block design with three replications of five plants per plot. Non-selected plant seeds and genetic material commercialized in Brazil were used as control. The genotype x environment interaction was significant for the J. curcas grain yield expression. We identified eight progenies of broad adaptability, three progenies of low adaptability, two progenies of specific adaptability to favorable environments and two progenies of specific adaptability to unfavorable environments of different Brazilian regions. Estimates of genetic progress indicate mass selection efficiency, with genetic gains of 28%, 76% and 177% in the Planaltina-DF, New Porteirinha-MG and Pelotas-RS, respectively. The genetic gains obtained by the centroid method were more balanced among environments, and therefore, preferable. The new means estimated with the cultivating of the selected progenies are: 2.34 ton.ha-1 in Planaltina-DF, 2.37 ton.ha-1 in Nova Porteirinha- MG and 2.09 ton.ha-1 in Pelotas-RS.

Analysis of morpho-agronomic and climatic variables in successive agricultural years provides novel information regarding the phenological cycle of Jatropha in conditions of the Brazilian cerrado

Phenological studies can provide information that enables the understanding of the dynamics of plants and how these dynamics are related to the biotic and abiotic environment. In order to study the phenological phases of Jatropha during two agricultural years, agronomic and climatic variables, such as temperature and rainfall, were evaluated. Data for each variable in each year and each genotype were subjected to analysis of variance (ANOVA) and the differences were tested at 5% probability by F test. In addition, the correlation of growth behavior and reproductive development of two Jatropha accessions (CNPAE-102 and CNPAE-169) as a function of time elapsed after the start of the phenological cycle with climatic variables were analyzed through Pearsons correlation. It was found that: (i) the resuming of plant growth by producing new branches and flowers of both genotypes coincides with the start of the rainy season, (ii) the flowering may be related to the increase in temperature and rainfall; (iii) the number of inflorescences per plant and number of female flowers determine the number of green fruits, (iv) the environmental changes are responsible for the delimitation of phenophases; and finally that (v) the responses to phenological changes are genotype-dependent.

EMBRAPA 22: nova cultivar de trigo para Minas Gerais, Goiás e Distrito Federal

In a joint research program the Embrapa-Centro de Pesquisa Agropecuaria dos Cerrados (CPAC), the Embrapa-Centro Nacional de Pesquisa de Trigo (CNPT), the Empresa de Pesquisa Agropecuaria de Minas Gerais (Epamig), the Empresa Goiana de Pesquisa Agropecuaria (Emgopa, todays Emater-GO), and the Cooperativa Agropecuaria Mista do Programa de Assentamento Dirigido do Alto Paranaiba (Coopadap-MG), released a new cultivar ¾ EMBRAPA 22 ¾ indicated for areas with splinkler irrigation in the States of Goias and Minas Gerais, and Federal District. Recently this cultivar was recomended for Bahia and Mato Grosso States. EMBRAPA 22 is originated from crossings carried out in the International Center for Corn and Wheat Breeding (CIMMYT), Mexico. It was introduced in Brazil through line colections and was identified in the trials of the Central Brazil research network as line CPAC 841153. The cultivar has higher qualities for the bread industry; has low grain shattering, it is resistant to stem rust and leaf rust under field conditions, and shows medium tolerance to lodging. In several trials, in different places and years, the yield of EMBRAPA 22 was 6% higher than the cultivar control Anahuac in Goias and Federal District and 4% higher in Minas Gerais State.