In this work, analytical pyrolysis (Py-GC-MS) was employed to identify lignin markers derived from H, S, and G phenylpropanoid units in sugarcane bagasse. Temperatures of 450 and 500 • C allowed the detection of key products that were informative on the bagasse lignin composition. The method was validated by comparing the S/G ratio as determined by the nitrobenzene oxidation (NBO) standard method for five sugarcane varieties. The S/G ratio as determined by Py-GC-MS, taking into consideration all known lignin markers in the analysis, resulted in a correlation coefficient of 0.85 with a linear regression coefficient of 0.74. When a group of selected markers (M2) was used, the correlation coefficient between methods was improved to 0.95 and the linear regression coefficient was adjusted to 0.92. M2 markers consisted of five syringyl markers (syringol, 4-methylsyringol, 4-ethylsyringol, 4-vinylsyringol, and trans-4-propenylsyringol) and four guaiacyl markers (guaiacol, 4-vinylguaiacol, 4-methylguaiacol, and vanillin). Importantly, Py-GC-MS allowed for the study of lignin composition in sugarcane bagasse without the need to remove the extractives, minimizing the work with sample preparations.

ResumoFoi realizada estratégia de integração dos dados quantitativos e multicategóricos para avaliação da divergência genética entre 88 acessos de Coffea arabica. Avaliaram-se 12 características quantitativas (nota total da qualidade sensorial da bebida; peso de três litros de "café da roça"; peso de três litros de "café da roça" com 11% de umidade; porcentagem de café beneficiado a partir de três litros de "café da roça" com 11% de umidade; peso de três litros de café beneficiado com 11% de umidade; total de frutos de "café da roça" em um litro; porcentagem de frutos secos, passas, cereja, verde-cana e verdes em um litro de "café da roça"; e porcentagem de frutos com lojas vazias em um litro de "café da roça") e seis características multicategóricas relacionadas à qualidade sensorial da bebida (doçura, acidez, corpo, sabor, retrogosto e aspecto geral). Baixa divergência genética foi encontrada entre os acessos considerando as características quantitativas e multicategóricas isoladamente. No entanto, com a conversão dos dados quantitativos em multicategóricos, a integração de características de diferentes naturezas favoreceu a melhor visualização da divergência genética entre os acessos avaliados, devido ao maior número de grupos formados em comparação ao agrupamento para cada conjunto de características.Palavras-chave: Coffea arabica L., análise multivariada, banco de germoplasma.Integration of quantitative and multicategorical data in determining the genetic divergence among accessions of coffee trees AbstractThe strategy of integrating quantitative and multicategorical data was performed to evaluate genetic divergence among 88 accessions of Coffea arabica. Twelve quantitative traits were evaluated: total score of cup quality; weight of 3 L of "farm coffee"; grain yield; weight of 3 L of "farm coffee" with 11% moisture; weight of 3 L of processed coffee with 11% moisture; total "farm coffee" fruit in 1 L; percentage of dry grains, overripe grains, cherry grains, green-cane grains and green grains in 1 L of "farm coffee"; percentage of fruits with empty-locus in 1 L of "farm coffee". Six multicategorical traits related to cup quality (sweetness, acidity, body, taste, after taste, and general aspect) were also evaluated. Low genetic divergence among accessions was found when the analysis of quantitative and multicategorical data was taken individually. However, the integration of the traits favored a better visualization of genetic divergence among the evaluated accessions when the quantitative data were converted into multicategorical ones. This occurred because of the increased number of groups formed when the integration strategy was used.

Sugarcane (Saccharum spp.) bagasse is recognized as a promising feedstock for cellulosic ethanol production. e development of high-quality crop cultivars through plant breeding is a way to improve feedstock quality. is study aimed to directly and indirectly quantify the e ects of agronomic characteristics on the sacchari cation of sugarcane bagasse samples and to identifying the characteristics that can be used as reliable tools for the selection of genotypes for a better biofuel feedstock. e lignin content was determined in bagasse samples of 286 clones from 13 half-sib families. Twenty clones showing a more contrasting lignin content were analyzed for the cellulose and hemicellulose composition in bagasse. ey di ered statistically for cellulose and hemicellulose contents and also for the e ciency of cellulose to glucose conversion. Clones with the highest dry biomass content also had the highest ber content and were grouped among the clones exhibiting the highest lignin content. Lignin content was statistically signi cant and positively correlated with ber (r = 0.485, p < 0.05) and plant biomass (r = 0.654, p < 0.01), and hemicellulose content was statistically signi cant and positively correlated with number of internodes (r = 0.623, p < 0.01). Lignin content and plant biomass had large negative direct e ects (0.405 and 0.784, respectively) on glucose released by enzymatic hydrolysis. Variation among clones for plant productivity parameters and chemical composition of bagasse could be exploited by breeding to increase the amount of cellulosic ethanol produced. Lignin content and plant biomass were the most important components with direct and negative in uences on the conversion of cellulose to glucose.

Low P availability in the soils of tropical regions is one of the main factors limiting agricultural production. Improving the efficiency of P use in plants is recognized as a less onerous and more sustainable method of maintaining satisfactory production in P-deficient soil. The aims of this study were to assess the existence of genetic variability for P use efficiency in sugarcane (Saccharum spp.) and to identify useful variables for the selection of efficient and responsive genotypes under low-and high-P conditions. The experiment was conducted in a greenhouse with 23 genotypes and two rates of P (40 and 240 kg ha -1 ) for 8 mo. We derived variables related to P absorption, accumulation, and utilization efficiency (PUE). Genotypes with similar productivities under high-P conditions varied widely in P-deficient soil. By measuring the production of dry aboveground mass, efficient genotypes under low-P conditions could be identified and classified regarding their efficiency and responsiveness to P. It was possible to classify the genotypes according to their P absorption efficiency (PAE) using the recovery rate of P and the root efficiency ratio. Regarding P accumulation, there was greater accumulation in the roots than in the stalks or leaves under low P. Under optimal P conditions, PUE measurements in the stalks and in the aboveground parts of the plant could be used to effectively select genotypes with superior nutrient use. Under low-P conditions, the PAE was more important in genotype selection.

ABSTRACT. Superior inbred clones selected in S 1 families can integrate an individual reciprocal recurrent selection program in sugarcane by eliminating the genetic load of the population and exploring superior hybrid combinations. Molecular markers can be used for reliable identification of the true selfing-derived clones in these S 1 populations. The objective of this study was to confirm true self-fertilized individuals in sugarcane families using microsatellite markers aimed at the use of self-fertilized plants in an individual reciprocal recurrent selection strategy. Self-fertilized individuals Selfing confirmation and recurrent selection in sugarcane using SSR from five cultivars were genotyped with eight simple sequence repeat (SSR) markers. The markers generated 62 polymorphic markers, with an average of seven polymorphic alleles across the cultivars tested. Three loci revealed highly informative bands and were used to assess the level of selfing in five S 1 families. Selfing in these families ranged from 71.7 to 97.6%. The SSR loci provide a reliable and accurate method to identify S 1 progenies in sugarcane crosses and can be used as a tool to assist selection strategies in sugarcane breeding programs.

-The cultivar of irrigated rice BRSMG Predileta has high grain yield, resistance to the main rice diseases and produces good quality grains for industry and cooking. It was recommended in 2007 by the Genetic Improvement Program for lowland rice in Minas Gerais, developed by EPAMIG in partnership with Embrapa Arroz e Feijão.

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O presente trabalho teve por objetivo aplicar a teoria de modelos mistos para predizer os valores genotípicos e estimar os parâmetros de adaptabilidade e estabilidade de clones de cana-de-açúcar avaliados no delineamento de blocos aumentados em vários ambientes e, também, avaliar a correlação existente entre estes valores preditos e, ou estimados. Foram utilizadas as metodologias de Wricke (Wricke & Webber, 1986), Eberhart & Russell (1966) e Carneiro (1998). Os valores genotípicos preditos livres dos efeitos da interação genótipos x ambientes mostraram-se fortemente correlacionados com os parâmetros estimados pela metodologia de Carneiro, moderadamente correlacionados com os parâmetros de adaptabilidade ( ) do método de Eberhart and Russel e fracamente correlacionados com o parâmetro ωi (%) de Wricke e com o parâmetro R2i (%) de Eberhart and Russel. O parâmetro ωi (%) apresentou correlação significativa apenas com o parâmetro R2i (%) de Eberhart e Russell, indicando a semelhança de ambos em avaliar a estabilidade dos genótipos. Esses resultados revelam que os valores genotípicos preditos livres dos efeitos da interação genótipos x ambientes correlacionam-se mais com a adaptabilidade do que com a estabilidade.