Sugarcane (Saccharum spp.) is currently one of the most efficient crops in the production of first-generation biofuels. However, the bagasse represents an additional abundant lignocellulosic resource that has the potential to increase the ethanol production per plant. To achieve a more efficient conversion of bagasse into ethanol, a better understanding of the main factors affecting biomass recalcitrance is needed. Because several studies have shown a negative effect of lignin on saccharification yield, the characterization of lignin biosynthesis, structure, and deposition in sugarcane is an important goal. Here, we present, to our knowledge, the first systematic study of lignin deposition during sugarcane stem development, using histological, biochemical, and transcriptional data derived from two sugarcane genotypes with contrasting lignin contents. Lignin amount and composition were determined in rind (outer) and pith (inner) tissues throughout stem development. In addition, the phenolic metabolome was analyzed by ultra-highperformance liquid chromatography-mass spectrometry, which allowed the identification of 35 compounds related to the phenylpropanoid pathway and monolignol biosynthesis. Furthermore, the Sugarcane EST Database was extensively surveyed to identify lignin biosynthetic gene homologs, and the expression of all identified genes during stem development was determined by quantitative reverse transcription-polymerase chain reaction. Our data provide, to our knowledge, the first in-depth characterization of lignin biosynthesis in sugarcane and form the baseline for the rational metabolic engineering of sugarcane feedstock for bioenergy purposes.

-The objective of this work was to evaluate the oviposition preference of Diatraea saccharalis and the effect of ten sugarcane cultivars on larval development. Oviposition preference was assessed under greenhouse conditions by three releases of couples of moths, with subsequent counting of egg masses and eggs per plant. In order to evaluate the effect of the cultivars on larval development, each plant was infected with about 150 eggs, and, 29 days later, the total number of internodes, number of bored internodes, number of life forms found, larval and pupal weight and length, and the width of larval head capsule were evaluated. The cultivars IACSP94-2101 and IACSP96-2042, the least preferred by D. saccharalis for oviposition, and IACSP94-2094, the most unfavorable for larvae entrance and development, show resistance to the pest.Index terms: Saccharum, antibiosis, antixenosis, sugarcane borer. Resistência de cultivares de cana-de-açúcar a Diatraea saccharalisResumo -O objetivo deste trabalho foi avaliar a preferência de oviposição de Diatraea saccharalis e o efeito de dez cultivares de cana-de-açúcar no desenvolvimento larval. A preferência para oviposição foi avaliada em casa de vegetação, por meio de três liberações de casais da praga, com posterior contagem de posturas e de ovos em cada planta. Para avaliar o efeito das cultivares sobre o desenvolvimento da fase larval, cada planta foi infestada com cerca de 150 ovos e, após 29 dias, foram avaliados: número de entrenós totais, número de entrenós brocados, número de formas biológicas encontradas, peso e comprimento das lagartas e das pupas, e largura da cápsula cefálica das lagartas. As cultivares IACSP94-2101 e IACSP96-2042, as menos preferidas por D. saccharalis para oviposição, e IACSP94-2094, a mais desfavorável para a entrada e o desenvolvimento das lagartas no interior dos colmos, apresentam resistência ao inseto.Termos para indexação: Saccharum, antibiose, antixenose, broca-comum.

Sugarcane (Saccharum spp.) is an efficient and sustainable alternative for energy generation compared to non-renewable sources. Currently, during the mechanized harvest process, the straw left in the field can be used in part for the second generation ethanol and increasing the electric energy production. Thus, this study aimed to provide information on the potential for residual biomass cultivars of sugarcane cropping system. This study provides the following information: yield of straw, depending on the calculated leaf area index and the number of tillers per linear meter; primary energy production of several sugarcane genotypes; contribution of dry tops and leaves; biomass yield; and evaluation of fiber, cellulose, hemicellulose and lignin. Preliminary results obtained by researchers of the State of São Paulo, Brazil, and reCviews related studies are presented. The results suggest that the production of sugarcane straw content varies according to the cultivars; the greater mass of sugarcane straw is in the top leaves and that the potential for the crude energy production of sugarcane per area unit can be increased using fiber-rich species or species that produce more straw. The straw indexes was shown to be a good indicator and allow the estimation of straw volumes generated in a sugarcane crop. The cellulose, hemicellulose and lignin composition in sugarcane is distinct among varieties. Therefore, it is possible to develop distinct biomass materials for energy production and for the development of sugarcane mills using biochemical processes and thermal routes.

The spittlebug Mahanarva fimbriolata (Stål) (Hemiptera: Cercopidae) is one of the most important pests of sugarcane in Brazil. Measures for population control are currently restricted to the use of chemical insecticides and fungus Metarhizium anisopliae, in part because very little information exists regarding resistance of sugarcane cultivars. Therefore, the aim of this study was to evaluate resistance mechanisms of 12 different sugarcane cultivars to M. fimbriolata to provide information for growers for pest management. Isolated buds of each cultivar were planted in pots and kept in a greenhouse for approximately three months. The pots were then moved to climate test chambers (26 ± 1 ºC; 70 ± 10 % relative humidity; 12 h photoperiod) to carry out laboratory tests to evaluate adult feeding and female oviposition preferences (using both free-choice and no-choice tests) as well as the effects of cultivars on nymph development and cultivars tolerance to pest attack. The least attractive cultivars for adult feeding were

The objectives of this study were to determine the range of neutral detergent fibre (NDF) digestibility across sugarcane varieties and predict dry-matter (DM) and NDF digestibility based on morphological and chemical composition. Whole plants of thirty-two commercial varieties were collected after 12 months regrowth (second cut) and evaluated for morphological traits, chemical composition, in situ digestibility of NDF (NDFD) and of DM (DMD), in vitro NDFD (IVNDFD) and gas production dynamics from isolated NDF. The content of NDF ranged from 404 to 547 g kg À1 DM, DMD was between 593 and 739 g kg À1 and NDFD varied from 270 to 363 g kg À1 . Cluster and discriminant analyses for NDFD agglomerated sugarcane genotypes into three groups (high, medium and low NDFD). The contents of NDF and lignin were the best univariate predictors of sugarcane DMD and NDFD respectively. Therefore, associating NDF and lignin improved the accuracy of DMD prediction. Associating lignin concentration with the number of dry leaves and stalk length significantly improved the goodness of fit of NDFD prediction. Contrary to expectations, silicon concentration was not related to NDFD. The principal component analysis patterned the content of neutral detergent solubles, NDFD and variables related to DM yield in different components. Hence, these characteristics would coexist in the same variety. Based on Lucas test and kinetics of gas production from NDF, sugarcane potentially digestible NDF (pdNDF) can be considered almost uniform (pdNDF digestibility = 677 g kg À1 ). In conclusion, associating chemical composition and morphological traits can successfully improve the screening of sugarcane genotypes for animal nutrition.