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Brown rust is an important disease that can affect the production of sugarcane in susceptible varieties. Reaction to brown rust has influenced the improvement programs in the process of clonal selection. Bru1 is one of the main resistance genes for brown rust. Therefore, the knowledge of the reaction to brown rust in the genotypes most used as parents in hybridizations would avoid crosses between susceptible genotypes. In this sense, the objectives of this work were to evaluate the reaction to brown rust in the field and the pattern of disease evolution; and the presence of the Bru1 gene in sugarcane parents of the RIDESA genetic improvement program. The experiment was carried out at the Paranavai experimental station, where 64 genotypes were planted in a randomized block design with three replications. The severity of brown rust in the field under natural infection conditions and the presence of the Bru1 gene were evaluated. Of the 63 genotypes evaluated, 38 were classified as resistant, 13 as intermediate and 12 as susceptible. Lower values of severity of brown rust were observed in intermediate genotypes with a slow evolution of the disease when compared with susceptible parents, indicating a quantitative resistance. Bru1 was detected in 58.7% of the evaluated genotypes. The frequency of Bru1 increased from 0% in the genotypes used as parents in the 1970s to 20, 64.71 and 76% in the 1980, 1990 and 2000s, respectively.

Orange rust (OR) and brown rust (BR) are among the most important diseases of sugarcane. The objective of this work was to evaluate the efficiency of fungicides in the control of both rusts. Two experiments, one for each rust, were conducted in the state of Parana, Brazil, in plant cane and in ratoon. A randomized block design with 8 treatments and three replications was used. The treatments were: control (T1), pyraclostrobin (T2), pyraclostrobin + epoxiconazole (T3), azoxystrobin + cyproconazole (T4), azoxystrobin + tebuconazole (T5), trifloxystrobin + tebuconazole (T6), azoxystrobin + benzovindiflupyr (T7) and pyraclostrobin + fluxapyroxad (T8). The cultivars RB72454 and RB835486 were used for their susceptibility to OR and BR, respectively. Four applications of fungicides were carried out in plant cane and also in ratoon, in a 30-day intervals. With the severity data over time, the relative area under the disease progress curve (rAUDPC) was calculated. After harvest, yield (tons of cane per hectare-TCH), yield recovery compared to the control (YR) (%), pol% cane (PC) and tons of pol per hectare (TPH) were obtained. From rAUDPC results, treatments T3, T4, T5, and T7 were the most efficient for the control of OR and treatments T2, T3, T4, T5, T7 and T8 were the most efficient for controlling BR. Yield was affected by treatments only in ratoon in both experiments. The YR ranged from 18.5% to 31.1% and from 16.1% to 37.7% to OR and BR, respectively. There were no differences between treatments for PC in both experiments and TPH was influenced by treatments in ratoon in the BR experiment.

This study's objectives were to compare the occurrence of brown rust and smut in conventional and energy cane families and clones in field conditions and to understand how the new hybridizations could contribute to increasing the allele frequency of resistance against the main crop diseases in breeding populations. Disease occurrence was evaluated in two selection stages. Of the 2.400 clones constituting the material for selection in the first stage, 88 clones (« 4% of the total) were selected for the second stage. Considering the overall performance of the clones without symptoms of either disease in the evaluated families that would be possibly selected in the second stage, the percentage was at least 28% lower in the families selected for high biomass (37.33%) than of the selected conventional (57.14%) and intermediate biomass (66.67%) families. In the intermediate biomass and high biomass sugarcane families, brown rust and smut rates were higher in the first stage. In the second stage, brown rust incidence was higher in high biomass families. However, at the end of both selection phases, intermediate biomass and high biomass sugarcane clones without simultaneous brown rust and smut symptoms could be selected.

Cold stress reduces crop yields and quality, limiting agricultural expansion. The objective of this study was to evaluate cold tolerance in sugarcane (Saccharum spp.) progenies based on physiological and biometric characteristics under natural cold stress. The experiment was carried out at a station of the Temperate Climate Research Center, of the Brazilian Agricultural Research Corporation (Embrapa), in Pelotas, Rio Grande do Sul, where 21 full-sib sugarcane progenies were evaluated in an incomplete block design with six replications. Physiological and biometric characteristics were measured after frost events to determine cold tolerance. The components of variance, genetic parameters and correlations were estimated using mixed models (REML/BLUP). The meteorological data recorded on-site showed the occurrence of 13 frost events (0 °C) and a minimum temperature of − 2.9 °C. Genetic variability for cold tolerance was detected between and within progenies. Narrow-sense heritability was moderate for chlorophyll content (0.23), leaf damage (0.26), stalk damage (0.19) and total soluble solids content (0.44), while heritability at the progeny level was high for all traits (> 0.57). The genotypic values for cold tolerance and yield potential were highest in the progenies RB996962 × RB016916, RB016916 × RB996962, RB867515 × RB92579 and RB106802 × RB036088.

Orange rust, caused by the fungus Puccinia kuehnii, is an important disease of sugarcane (Saccharum sp.). A molecular marker (G1) was developed to identify the resistance of sugarcane to orange rust. The aim of the present study was to validate the molecular marker G1 in the detection of resistance to orange rust in Brazilian sugarcane genotypes. 80 genotypes were analyzed by PCR, being classified according to the presence or absence of the marker. For field evaluation of orange rust resistance, a randomized block experiment was conducted, with the same 80 genotypes using four replications. Artificial inoculation was performed in the leaf whorl, with an evaluation made at 30 days after inoculation, using a scale from zero (without symptoms) to four (more than five pustules with sporulation), in which cultivars with an average score between zero and two were classified as resistant, and a score greater than two, susceptible. Of the 17 genotypes classified as resistant through the field test, 9 did not present the respective band. Of the 63 susceptible genotypes, 27 had the band relative to the molecular marker G1. The selection accuracy of G1 marker (the efficiency of predicting resistant phenotype) was 22.86%. The Phi correlation coefficient (ϕ) was calculated, through which it was observed that the variables are independent, with no statistically significant correlation between them. The results indicate that the G1 marker had a low efficiency to predict the resistance to orange rust in clones under selection in a Brazilian breeding program and Brazilian commercial cultivars of sugarcane.

Functional genomics along with genetic transformation and plant regeneration are used to identify genes of interest, comprising essential tools to obtain plants with desired characteristics. In this study, we described an organogenesis and a genetic transformation protocol for Populus tremula x Populus alba clone 717-1B4 using roots. In the organogenesis experiments the PGRs zeatin, BA and kinetin at different concentrations were evaluated. The effect of explant age was evaluated and at 30 days “old” roots (6 months old) showed a higher regeneration rate when compared to “young” roots (2 months old). In the genetic transformation experiments kanamycin concentration, the use of sonication (SAAT), co-cultivation period and explant age were evaluated. Sonication positively affected transformation, while co-cultivation time did not interfere. Regarding explant age, no statistical differences were observed. Quantitative real-time PCR (qPCR) data showed that among the six transgenic plants evaluated, two presented two copies and the others only one copy of the gene. In this study, efficient protocols of organogenesis and genetic transformation for poplar roots are presented with a transformation efficiency of 58%.

In response to the new requirements of the sugar-energy sector, sugarcane breeding programs are addressing the selection of clones for different purposes, e.g., sucrose production, ethanol production for first-generation (1G) and second-generation (2G) biofuels. Consequently, agronomic variables such as fiber content, sucrose content and biomass yield, become more relevant in the selection process, for underlying the definition of conventional, high biomass and multipurpose ideotypes. The relation between fiber and sucrose contents and biomass quantity should be used to differentiate thee different clone types: conventional clones, with high sucrose content and high biomass; high biomass, with high fiber content and high biomass; or multipurpose, with high fiber and sucrose contents and high biomass. In view of the difficulty of selecting different ideotypes from the same population, the objective of this study was to develop a method of selecting sugarcane clones for the different purposes. A population with 220 clones derived from crosses involving parents of different Saccharum species were subjected to the new methodology of clone selection with a fuzzy controller programmed to classify experimental clones in three ideotypes. Apart from the selection involving real data, the fuzzy controller was tested on 26 simulated populations. The controller proved to be efficient in the classification and selection of clones from the three ideotypes with real and simulated data.

Brazil is the world's third largest beer consumer and currently imports all of its hops for the brewing industry. Such a fact justifies the selection of hop genotypes adapted for cultivation locally, which requires high quality seeds and efficient sex determination of the seedlings. The objectives of this study were to develop a methodology to assess hop seed quality and to efficiently determine hop seedling sex through the use of male-specific molecular markers. Freshly harvested hop seeds were germinated with and without pre-chilling (3-5 ° C) for 3, 6 and 12 weeks and then germinated at 20 or 25 ° C in the presence or absence of light, evaluating germination percentage and germination speed index. F1 progenies were obtained from after seed germination in a greenhouse and seedlings sex was determined using male-specific molecular markers. The best conditions for physiological quality assessment of hop seeds used in the present study were pre-chilling for 12 weeks, followed by germination at 25 ° C, and normal seedling counts at 7 and 15 days. The progeny submitted to molecular marker sexing was composed of 61.3% female plants. The established methodologies presented here can be considered efficient and may contribute to expedite hops breeding programs.

Os objetivos deste estudo foram avaliar a reação de 28 cultivares de cana-de-açúcar à ferrugem alaranjada, em campo, estabelecendo uma época de avaliação adequada para os programas de melhoramento e determinar os períodos de incubação e latência, incidência e severidade na cultivar padrão suscetível, em casa-de-vegetação. No campo, a severidade foi avaliada em cana-planta (dez meses) e em cana-soca (três, cinco, sete e nove meses). A partir destes dados, calculou-se a área abaixo da curva de progresso da doença (AACPD). Para estabelecer a época de avaliação adequada, calculou-se a correlação de Pearson entre os resíduos das datas com os da AACPD. Em casa-de-vegetação, inoculou-se a cultivar RB72454 e avaliou-se incidência e severidade. Das cultivares avaliadas, 14 foram suscetíveis à ferrugem alaranjada, sendo discriminadas em quatro grupos de suscetibilidade. A avaliação em maio (cana-soca, aos nove meses), foi a que mais se correlacionou com a AACPD, sendo a época adequada para avaliar a reação de cultivares à doença, no norte do Estado do Paraná. O período de incubação e latência na cultivar padrão suscetível foi de sete e dez dias, respectivamente. A cultivar RB72454 é a única altamente suscetível à ferrugem alaranjada e as demais avaliadas apresentam menores graus de suscetibilidade.

In the present study, the effects of two CaCl2.2H2O levels (440 and 1320 mg L-1) and two subcultures were evaluated on in vitro shoots of Lavandula angustifolia cv. Provence Blue. Ca2+ content of the apical, middle and basal portion of shoots was determined. Increasing CaCl2.2H2O level in the culture medium increased tissue Ca2+ content and decreased hyperhydricity. Shoot-tip necrosis also decreased with 1320 mg L-1 CaCl2.2H2O, but it did not occur in the second subculture. The middle and basal portion had higher Ca2+ content than apical portion. In non-hyperhydric tissues, there were smaller and more juxtaposed cells. Scanning electron microscopy of the leaves demonstrated that trichomes from in vitro leaf surface occurred in smaller quantities.

High salinity interferes in sugarcane growth and development, affecting not only crop yield but also reducing sucrose concentration in culms. Sugarcane plants submitted to salt stress can accumulate compatible solutes, such as proline, which may counteract the effects of salt accumulation in the vacuole and scavenge reactive oxygen species. The objective of this study was to evaluate the response to salt stress of sugarcane plants transformed with the Vigna aconitifolia P5CS gene, which encodes ∆1-pyrroline-5-carboxylate synthetase, under the control of a stress-induced promoter AIPC (ABA-inducible promoter complex). For this, 4-month-old clonally multiplied sugarcane plants from two transformation events were irrigated every 2 days with 1/10 Hoagland’s solution supplemented with 100, 150 and 200 NaCl, progressively, during 28 days. Transgenic lines showed increased transgene expression in 3.75-fold when compared with the control plants after 9 days of irrigation with saline water, which can explain the higher proline concentration found in these plants. At the end of the experiment (day 28), the transgenic lines accumulated up to 25 % higher amounts of proline when compared with non-transformed control plants. Stress response in transgenic plants was also accompanied by a reduction of malondialdehyde (MDA) derived from cellular lipid peroxidation in leaves, lower Na+ accumulation in leaves and maintenance of photochemical efficiency of PSII. Thus, proline contributed to the protection of the photosynthetic apparatus and the prevention of oxidative damage in transgenic sugarcane under salt stress.

http://dx.doi.org/10.5902/1980509814572Os objetivos deste trabalho foram avaliar diferentes meios de cultura na organogênese indireta e na multiplicação in vitro de brotos de Eucalyptus benthamii x Eucalyptus dunnii. Para organogênese, explantes foliares foram excisados no sentido transversal e cultivados in vitro, sendo os seguintes fatores testados: dois meios de cultura (MS N/2 e JADS) adicionados de 0,1 μM de ANA, duas concentrações de thidiazuron (0,1 e 0,5 μM) e presença ou não de PVP-40 (250 mg L-1). Após 70 dias de cultivo foram avaliadas as porcentagens de explantes oxidados totalmente, formando calo, produzindo antocianina, formando gema, formando brotações e o número de brotações formadas por explante regenerando. No experimento de multiplicação, brotações isoladas foram cultivadas em meio MS, JADS e WPM, adicionados de 1,11 μM de BAP. Foram realizados quatro subcultivos a cada 28 dias e em cada subcultivo foram avaliados: a porcentagem de oxidação, de explantes apresentando clorose total ou parcial, massa fresca e número médio de brotos por explante. O meio de cultura MS N/2 suplementado com 0,1 μM de ANA, 0,5 μM de TDZ e PVP-40 promoveu a maior taxa de organogênese (8,3%). No meio de cultura MS com 1,11 μM de BAP, a taxa de multiplicação foi maior que nos outros meios, no primeiro e segundo subcultivos (9,28 e 9,24 por mês), não havendo diferença entre os três meios nos demais subcultivos.

Polyploid plants can exhibit transcriptional modulation in homeologous genes in response to abiotic stresses. Coffea arabica, an allotetraploid, accounts for 75 % of the world’s coffee production. Extreme temperatures, salinity and drought limit crop productivity, which includes coffee plants. Mannitol is known to be involved in abiotic stress tolerance in higher plants. This study aimed to investigate the transcriptional responses of genes involved in mannitol biosynthesis and catabolism in C. arabica leaves under water deficit, salt stress and high temperature. Mannitol concentration was significantly increased in leaves of plants under drought and salinity, but reduced by heat stress. Fructose content followed the level of mannitol only in heat-stressed plants, suggesting the partitioning of the former into other metabolites during drought and salt stress conditions. Transcripts of the key enzymes involved in mannitol biosynthesis, CaM6PR, CaPMI and CaMTD, were modulated in distinct ways depending on the abiotic stress. Our data suggest that changes in mannitol accumulation during drought and salt stress in leaves of C. arabica are due, at least in part, to the increased expression of the key genes involved in mannitol biosynthesis. In addition, the homeologs of the Coffea canephora subgenome did not present the same pattern of overall transcriptional response, indicating differential regulation of these genes by the same stimulus. In this way, this study adds new information on the differential expression of C. arabica homeologous genes under adverse environmental conditions showing that abiotic stresses can influence the homeologous gene regulation pattern, in this case, mainly on those involved in mannitol pathway.

The climatic influence in minerals content of peach palm heart (Bactris gasipaes Kunth) was studied and a quick method was assessed to determine Mg, Cl, K and S in the basal portion of peach palm heart based on multivariate predictive model using agro-meteorological data. A total of 24 samples of B. gasipaes Kunth were collected along 14 to 18 months of cultivation, growing in two types of terrain: hillside and lowland. Principal component analysis (PCA) was used to select principal components. The data were modeled using partial least squares regression (PLS). Low average relative prediction errors (4.60%) confirm the good predictability of the models. The factors that most influence the minerals content prediction model were the rain precipitation and solar radiation. The results show that predictive model can be used as rapid method to determine the mineral content in the basal portion of peach palm heart factories and may help to choose geographical regions suitable for the establishment of new peach palm plantations. The models can provide reductions of cost and time analysis to palm heart without generating laboratory effluents. This is the first time in which multivariate analysis is used to generate models to predict minerals concentration in the basal portion of peach palm hearts, quantifying numerically the intensity of climatic factors in the minerals content.

The response of sugarcane (Saccharum spp.) families to the inoculation with plant growth-promoting bacteria (PGPB) may show positive or negative interaction values depending on the plant genotype, allowing the selection of responsive genotypes to the association. Based on these precepts, this study aimed to evaluate the response of 27 sugarcane families treated with two PGPB-based inoculants in two sugarcane cycles: plant-cane and first ratoon. Four months after germination, 27 families from crosses between clones of sugarcane were: (T0) not inoculated; (T1) inoculated with Triazo, which consists of a mixture of the strains Abv5, Abv6, and Abv7 of Azospirillum brasilense; and (T2) inoculated with an inoculant called Mix, which contains five strains of PGPB (Gluconacetobacter diazotrophicus Pal5, Azospirillum amazonense CBAmC, Burkholderia tropica Ppe8, Herbaspirillum rubrisubalbicans HCc103, and Herbaspirillum seropedicae HRC54). The productivity traits evaluated were the number of stalks, average height, stalk diameter, and Brix. The correlation values between the two cycles were 0.87 for the number of stalks, 0.70 for average height, 0.48 for stalk diameter, and 0.63 for Brix. Differences were observed between treatments for average height, stalk diameter, and Brix. Differences were also observed between families for all the studied traits. Brix was the only parameter that presented a significant interaction between family and inoculant. Different responses were observed between cycles for some families, showing that other factors can also influence the association.

Sugarcane is of great economic importance worldwide. Hence, there is great interest in the development of effi­cient techniques for the production of good quality, homogeneous, disease- and pest-free seedlings. One way to eliminate viruses is through meristem culture. To guarantee success during meristem culture, it is necessary to optimize the components and concentrations of the culture medium. Sucrose is an essential component in the culture medium, serving as a source of carbon and energy for the seedlings. Nitrogen, in turn, is essential in plants because it is a component of biomolecules and countless enzymes. This work evaluates the best combina­tion of nitrogen (75, 100, 125, and 150%) and sucrose (0, 20, 30, and 40 g L -1 ) concentrations in the in vitro multi­plication and development of sugarcane cultivar RB036091. The design was completely randomized, in a factorial scheme with four replicates and five explants per experimental unit. The concentration of 20 g L -1 sucrose with 100% nitrogen, from the original formulation of the MS culture medium, provided a better response in sugarcane multiplication.

At present, the sugarcane (Saccharum spp.) breeding programs from around the world have practiced early family selection, because in the early stages of breeding the evaluated characteristics have shown low heritability. This study aimed to select through restricted maximum likelihood/best linear unbiased prediction also known “mixed models” the best families among the 78 that comprise the RB05 sugarcane series, stage T1, of Programa de Melhoramento Genetico da Cana-de-acucar of the Rede Interuniversitaria para o Desenvolvimento do Setor Sucroalcoleiro, Brazil. The experiments, conducted during 2007/2008 and 2008/2009 in Paranavai, PR were implemented using an incomplete-block design with five replicates of each family. Each plot was composed of two planting rows of 5 m, spaced from each other by 1.40 m and spacing between plants was of 0.50 m, containing ten seedlings for planting row, resulting in a total of 20 individuals per replicate of each family. The characteristics evaluated were Brix (°Brix), ton of stalk per hectare (TCH) and ton of °Brix per hectare (TBH). The joint analysis obtained from these three traits in both harvests favored the selection of 35–41 families. The analysis also favored the selection of the best parents. The top five families for Brix were: F41M60, F02M77, F41M82, F61M38 and F62M35; to TCH were F66M30, F35M06, F78M45, F70M30 and F57M46 and for TBH the five elites families were F66M30, F35M06, F78M45, F70M30 and F01M39. The five best sugarcane parents for Brix were RB835486, SP91-1049, SP80-3280, RB72454 and RB925211; to TCH were IAC87-3396, RB941531, RB855511, RB915141 and RB957689, and for TBH the elite were IAC87-3396, RB855511, RB957689, RB941531 and RB855563. As each harvest season had different order of the best families, the joint analysis proved to be a primordial tool for plant breeders.

The stability of soybean genotypes is very important in breeding programs for not only the evaluation, selection, and production of cultivars but also the establishment of parameters required for the classification of genotypes into relative maturity groups (RMG). The aim of this study was to define stable genotypes for traits, such as days to flowering, days to maturity, and length of the reproductive period, and to classify them into RMG. For this purpose, 20 commercial soybean cultivars were evaluated in 12 environments distributed in the major producing regions of Brazil. Assessments according to the Eberhart and Russell method and the additive main effects and multiplicative interaction (AMMI) method were effective in the identification of stable genotypes and their classification into RMG. These methods can also be used collectively for this purpose. Our results showed that the AMMI method led to a better interpretation of genotype-environment interactions. Thus, RMG obtained on the basis of stable genotypes represented a good estimate of the relative maturity of soybean crops throughout Brazil. *Corresponding author.

In this study we investigated the effects of the high endogenous proline level on water relations, gas exchange and antioxidant enzymatic activity in leaves of transgenic ‘Swingle’ citrumelo rootstocks transformed with the P5CSF129A gene coding for the key-enzyme for proline synthesis, under water deficit. Leaf total water, osmotic and pressure potentials, stomatal conductance, photosynthetic rates and xylem sap flow were evaluated in non-transformed control and transgenic plants during water deficit treatment. Malondialdehyde (MDA) content, catalase (CAT; EC 1.11.1.6), superoxide dismutase (SOD; EC 1.15.1.1) and ascorbate peroxidase (APX; EC 1.11.1.11) activities were quantified in leaves collected based on their total water potential, representing the following conditions: irrigated ( Ψ w = −1.3 MPa), moderate stress ( Ψ w = −2.3 to −2.5 MPa), severe stress ( Ψ w = −3.8 to −3.9 MPa) and recovery (24 h after re-irrigation: Ψ w = −1.3 to −1.9 MPa). Osmotic adjustment was observed in transgenic plants until 11 days after withholding water, while pressure potential in non-transformed controls was close to zero after nine days of water deprivation. This superior maintenance of turgor pressure in leaves of transgenic plants led to higher stomatal conductance, photosynthetic and transpiration rates when compared to non-transgenic plants. Drought caused a significant decrease in APX and SOD activities in control plants, followed by an increase after re-watering. On the other hand, CAT was more active in control than in transgenic plants under irrigated condition and both stress levels. Our results suggest that transgenic plants were able to cope with water deficit better than non-transformed controls since the high endogenous proline level acted not only by mediating osmotic adjustment, but also by contributing to gas exchange parameters and ameliorating deleterious effects of drought-induced oxidative stress.

O objetivo deste estudo foi o estabelecimento de um protocolo de regeneracao e aclimatizacao de plantas de cana-de-acucar de duas cultivares (RB931003 e RB98710) a partir de embrioes somaticos. Para o cultivar RB931003, a concentracao de 0,25 mg L -1 de BAP, foi eficiente e proporcionou a inducao de brotacoes em 80% das massas embriogenicas. Ja para o cultivar RB98710, as maiores porcentagens de inducao de brotacoes foram observadas na ausencia de BAP e na concentracao de 0,25 mg L -1 de BAP, os quais promoveram 70% e 75% de brotacoes nas massas embriogenicas, respectivamente. O meio de cultura MS isento de regulador vegetal apresentou-se adequado para o alongamento e enraizamento das brotacoes e a utilizacao do substrato composto por vermiculita mais os sais do meio de cultura MS foi eficiente na aclimatizacao das plantas de ambos os cultivares analisados. Palavras-chave: Saccharum spp. , 6-benzilaminopurina, cultura de tecidos, embriogenese

Daylily (Hemerocallis × hybrida Hort.) is a popular ornamental plant and hybrid cultivars are frequently selected for medium size, large number of flowers per stem, and flower color diversity. However, daylily selection is limited due to the lack of information on genetic parameters and their correlation to phenotypic characteristics. This study aimed at estimating genetic parameters and genetic correlations among full sib families of 13 daylily cultivars using REML/BLUP (restricted maximum likelihood/best linear unbiased prediction) and to select families with high genotypic values for plant height and number of floral buds per stem. Crosses were performed among those cultivars and 24 families were obtained. In the third year, plant height, leaf length and width, stem number, number of floral buds per stem, and number of floral buds per plant were evaluated. The estimates of average heritability of families were superior to the estimates of restrict individual heritability for all characters evaluated. High heritability estimates were obtained for plant height, leaf length, leaf width, stem number, and number of floral buds per plant. Selected families showed genetic gain of 19.80% for plant height, 32.48% for stem number, and 38.64% for number of floral buds per plant.

The hybrid Eucalyptus grandis x Eucalyptus urophylla presents high levels of productivity and potential for use in paper, cellulose and fiber industries. The bud organogenesis from leaf explants of two clones of E. grandis × E. urophylla was studied in order to verify the effect of several factors: subculture duration on multiplication medium, type of explants, entire and half leaves: basal and apical portions, and duration of the culture on a regeneration medium. Differences in organogenic capacity of the two clones tested were observed. The explant most recommended for organogenesis is the basal section of the leaf collected from shoot clusters subcultured every 17 days. Moreover, the leaf explants must be transferred to a fresh bud induction medium every five days. This study also aimed at evaluating factors affecting the genetic transformation of leaf explants with the uidA gene, via co-cultivation with Agrobacterium tumefaciens, such as the pre-culture of the explants on a specific medium, the duration of their co-culture with the bacteria and the addition of acetosyringone to the culture media. The best conditions for the expression of the uidA gene were two days of pre-culture of the leaf tissues, three days of co-culture with the bacteria and the addition of acetosyringone in pre- and co-culture media.

Global interest in sugarcane has increased significantly in recent years due to its economic impact on sustainable energy production. Sugarcane breeding and better agronomic practices have contributed to a huge increase in sugarcane yield in the last 30 years. Additional increases in sugarcane yield are expected to result from the use of biotechnology tools in the near future. Genetically modified (GM) sugarcane that incorporates genes to increase resistance to biotic and abiotic stresses could play a major role in achieving this goal. However, to bring GM sugarcane to the market, it is necessary to follow a regulatory process that will evaluate the environmental and health impacts of this crop. The regulatory review process is usually accomplished through a comparison of the biology and composition of the GM cultivar and a non-GM counterpart. This review intends to provide information on non-GM sugarcane biology, genetics, breeding, agronomic management, processing, products and byproducts, as well as the current technologies used to develop GM sugarcane, with the aim of assisting regulators in the decision-making process regarding the commercial release of GM sugarcane cultivars.

RB966928 is an early to medium maturing sugarcane cultivar and in Central-Southern Brazil it is harvested between April and June; it is recommended for planting in environments with medium to high soil fertility. It stands out with a high ratoon yield and with excellent sprouting in both plant cane and ratoon cane. It is tolerant to the major diseases of economic importance of sugarcane.

Tissue culture technique can be an important approach for the rapid propagation of Humulus lupulus L. (hop plant). The present study evaluated different culture media for hop plants (cv. Columbus) in vitro shoots multiplication, as well as ex vitro rooting and plantlets establishment under field conditions at Southern Brazil. The culture medium containing the plant growth regulator thidiazuron (TDZ) resulted in greater in vitro shoots multiplications (five shoots per explant). For microcuttings ex vitro rooting, indole-3-butyric acid (IBA) application at a concentration of 3000 mg L-1 resulted in higher rooting and survival percentages during acclimatization. After 90 days of acclimatization, the plantlets were transplanted under field conditions and had their development and productivity evaluated 122 days after transplanting. Micropropagated plants achieved 100% survival under field conditions. Nitrogen supply is highly necessary for hop plants initial development at Southern Brazil. Micropropagation is a viable technique for quality plantlet production of H. lupulus cv. Columbus.

Plant breeding is generally done through sexual reproduction even when the species is propagated asexually for commercial exploitation, as for example, in sugarcane. Therefore, the development of procedures to evaluate sugarcane seed viability is important for plant breeding programs. The objective of this research was to develop a methodology for analyzing the viability of sugarcane seeds (Saccharum spp.). Three crosses were used, two biparental crosses and one polycross. For the germination test study, two substrates (paper and sand) and three constant incubation temperatures (25 ºC, 30 ºC and 35 ºC), in the presence of constant light and also an alternating temperatures (20-30 ºC), with 8 hours light (30 ºC) and 16 hours darkness (20 ºC), were studied. Seedlings were evaluated every five days. The results demonstrated that temperature affected sugarcane seed germination with the most favorable conditions being the alternating temperature (20-30 ºC) and the constant temperature of 30 ºC on a paper substrate. O melhoramento de plantas geralmente é conduzido com o uso da reprodução sexuada, mesmo quando a espécie é multiplicada assexuadamente para a exploração comercial, como é o caso da cana-de-açúcar. Neste sentido, o desenvolvimento de procedimentos para avaliar a viabilidade de sementes de cana-de-açúcar é de grande interesse em programas de melhoramento genético. A pesquisa teve por objetivo o desenvolvimento de metodologia para avaliação da viabilidade de sementes de cana-de-açúcar (Saccharum spp.). Foram utilizadas três progênies, sendo duas provenientes de cruzamentos biparentais e uma progênie proveniente de policruzamento. Para o estudo do teste de germinação foram testados dois substratos (papel e areia), três temperaturas constantes de incubação (25, 30 e 35 ºC), na presença de luz constante, e uma temperatura alternada (20-30 ºC), com presença de luz por 8 horas (30 ºC) e escuro por 16 horas (20 ºC). As plântulas foram avaliadas em intervalos regulares de cinco dias. De acordo com os resultados obtidos, pode-se concluir que a temperatura interfere na germinação das sementes de cana-de-açúcar; sendo as condições mais favoráveis a alternância de temperatura (20-30 ºC) e a temperatura constante de 30 ºC, em substrato papel.

In the present study, we have analyzed transformed plants of the citrus rootstock Carrizo citrange constitutively expressing a Δ1-pyrroline-5-carboxylate synthetase mutant gene (p5cs), which encodes the rate-limiting enzyme of the proline biosynthetic pathway. Transgenic plants grew normally in vivo and accumulated high levels of proline in the leaves. In well-watered conditions, the photosynthetic rate of Carrizo citrange transgenic plants was not significantly different from the non-transformed control. The transgenic plants presented superior osmotic adjustment and significantly higher photosynthetic rate than the control plants after 15 days without watering. Under water deficit, the leaf water potential of non-transformed plants was close to zero after 17 days, and the photosynthetic rate was almost null 2 days later. On the other hand, in transgenic plants similar measurements were only observed after 24 days of water stress. The use of citrus rootstocks with increased proline accumulation appears to be a promising approach to maintain the productivity of plants under drought stress condition.

Studies were carried out to optimize the conditions for transient gene expression through particle bombardment on Carrizo citrange (Citrus sinensis x Poncirus trifoliata) thin epicotyl sections. The best conditions for transient GUS expression were: M-25 tungsten particles, 1550 psi helium pressure, 9 cm distance between specimen and DNA/particle holder and culture of explants in a high osmolarity medium (0.2 M mannitol + 0.2 M sorbitol) 4 h prior and 20 h after bombardment. Under these conditions, an average of 102 blue spots per bombardment (20 explants/plate) were achieved. This protocol is currently being used for transformation of Carrizo citrange and sweet orange (Citrus sinensis).Nosso objetivo é desenvolver um protocolo para transformação genética de Citrus através do bombardeamento de partículas usando cortes finos de epicótilo como explantes alvo. Neste trabalho foram otimizadas condições para a expressão transiente usando citrange carrizo (Citrus sinensis x Poncirus trifoliata) como modelo. Epicótilos de plântulas de citrange carrizo germinadas in vitro foram cortadas transversalmente em seções de 1 mm e cultivadas em meio MS com 5 miM no escuro. Depois de uma semana, explantes foram bombardeados com o plasmídio pE2113-GUS usando um aparelho de alta pressão de hélio (PDS 1000/He Bio-Rad). As melhores condições para a expressão transiente foram: partículas de tungstênio M-25, pressão de hélio de 1550 psi, distância de 9 cm entre os explantes e DNA/particle holder e cultivo dos explantes em meio com alta osmolaridade (0,2 M manitol + 0,2 M sorbitol) 4 h antes e 20 h depois do bombardeamento. Usando estes parâmetros, uma média de 102 pontos azuis por bombardeamento (20 explantes/placa) foi obtida. Este protocolo esta sendo usado atualmente para transformação de citrange Carrizo e adaptado para transformação de laranja doce (Citrus sinensis).

The goal of this research was to study the introgression of the high regeneration capacity of Lycopersicon pimpinellifolium Mill line WV-700, in recalcitrant tomato cultivars (L. esculentum Mill cvs. Petomech, Santa Rita and VFN-8) using backcrossing. Hypocotyl explants of in vitro germinated seeds were cultivated in half strength MS medium supplemented with 5mg/l 6-BA to assess their shoot regeneration capacity. The apical shoot of the in vitro germinated seeds were cultured on a separate medium. Apical shoots from genotypes showing high regeneration rates were acclimated in a glasshouse and used as pollen donors for the next backcrossing. After four backcrossings, the material showed a similar mean fruit weight for the cultivated tomato and a high regeneration capacity similar to the wild species. It is shown that L. pimpinellifolium can be used with success as donor parent to introgress in vitro regeneration capacity to recalcitrant tomato cultivars.

Sugarcane is the main source for sugar production and the most important crop for energy production, as well as for byproducts like ethanol and fibers in the world. With a complex genome, the plant has its species from crosses between species of the genus Saccharum, which were the basis for sugarcane breeding programs worldwide. The production of sugarcane has increased worldwide due to breeding programs that have developed more productive clones for specific uses and adapted to different climatic conditions. The future objective of breeding programs is to develop sugarcane with high productivity, high sucrose content, drought tolerance, and high production of ethanol and biomass, i.e., plants with high fiber content and with cell walls easily broken to favor the production of ethanol from bagasse, efficient plants with low nitrogen fertilizer use, and others, and consequently to reduce environmental impacts. Currently, the demand for products derived from sugarcane is consistently increasing; the ethanol byproduct has been pointed out as one of the important sources to feed the demand for renewable energy in fossil and nonrenewable fuel substitution programs in different countries around the world. This chapter describes the genetic improvement of sugarcane and its current goals.

The sugar cane is a crop widely planted because of the economic importance of its products, sugar and ethanol. Brazil is the largest producer and exporter of sugar, so the crop is often inserted in breeding programs. Genetic transformation strategy is used to obtain resistant and productive cultivars. Defined and optimized in vitro regeneration protocols are required to obtain transgenic plants. The aim of this study was to evaluate the influence of different concentrations of 2,4-D (2,4-dichlorophenoxyacetic acid) to obtain embryogenic callus on cultivars RB966928 and RB986419 clone. Immature leaves from 10 months old plants were used as a source of explants. Leaf 8 x 150 mm cylinders, segmented into 4 mm were inoculated on MS medium with five concentrations of 2,4-D (1, 3, 9, 16 and 27 ?M). A second experiment was conducted with concentrations 3, 9 and 16 ?M of 2,4-D. For both experiments, the dedifferentiation occurred in the dark. Calli were transferred after 45 days of subculture to new medium with the same concentrations of origin for their multiplication. The cultivar RB966928 had responses to somatic embryogenesis of 30 and 41% using 16 ?M of 2,4-D for the first and second experiments, respectively. The clone RB986419 showed respectively 26 and 80% formation of embryogenic callus, using 9 ?M of 2,4-D in the first and second experiment. The calli were transferred to MS medium without plant growth regulator. Seedlings were acclimatized and placed in a greenhouse. The best concentrations of 2,4-D for the formation of calli were 16 ?M for the cultivar RB966928 and 9 ?M for clone RB986419.

Abiotic stresses are among the most important factors that affect food production. One important step to face these environmental challenges is the transcriptional modulation. Quantitative real-time PCR is a rapid, sensitive, and reliable method for the detection of mRNAs and it has become a powerful tool to mitigate plant stress tolerance; however, suitable reference genes are required for data normalization. Reference genes for coffee plants during nitrogen starvation, salinity and heat stress have not yet been reported. We evaluated the expression stability of ten candidate reference genes using geNorm PLUS, NormFinder, and BestKeeper softwares, in plants submitted to nitrogen starvation, salt and heat stress. EF1, EF1α, GAPDH, MDH, and UBQ10 were ranked as the most stable genes in all stresses and software analyses, while RPL39 and RPII were classified as the less reliable references. For reference gene validation, the transcriptional pattern of a Coffea non-symbiotic hemoglobin (CaHb1) was analyzed using the two new recommended and the most unstable gene references for normalization. The most unstable gene may lead to incorrect interpretation of CaHb1 transcriptional analysis. Here, we recommend two new reference genes in Coffea for use in data normalization in abiotic stresses: MDH and EF1.

Background In Brazil, especially in the Southern region, stresses caused by cold and eventual frost are those that exert the most negative effect on the productivity of Eucalyptus spp. The genetic transformation techniques may contribute to forestry improvement programs in order to obtain genotypes expressing new interesting characteristics. They allow shortening the long breeding cycles and avoiding manipulation of adult trees. Their efficiency depends on establishment of regeneration procedures that allow the development of shoots from the transformed tissues. E. benthamiix E. dunnii hybrids have shown superiority to their parents concerning growth and frost tolerance [1], but no information about their in vitro organogenesis has been reported in the literature. The objective of this study was to evaluate the effect of some factors of culture medium on indirect organogenesis and shoot multiplication of anE. benthammi x E. dunnii clone. Methods In vitroestablished shoots,provided by EMBRAPA-Florestas (Colombo, PR, Brazil), were used as explant source. Cultures were maintained under white fluorescent tubes providing a photon flux density (PFD) of approximately 20 μmol m -2 s -1 , a 16-h photoperiod and a temperature of 25±2 °C. The cultures were performed in glass flasks containing 25 mL MS [2] medium supplemented with 1.11µM BA and sealed with rigid polypropylene caps. For the indirect organogenesis, leaves were excised from shoots at the petiole base, split into two halves and inoculated in culture media. The cultures were done in Petri dishes kept in a growth chamber in the dark throughout the experiment. The statistical design was performed in a factorial scheme (2:2:2) and a comparison was done between two culture media (MS-N/2, with half concentration of potassium and ammonium nitrates, and JADS [3] with 0.1 µM NAA, with and without PVP-40 (250 mg L -1 ) and two TDZ concentrations (0.1 and 0.5 µM). After 70 days, the percentages of explants forming callus, oxidized explants, explants producing anthocyanin, explants forming buds and shoots, and the number of shoots per explant were evaluated. For the multiplication test, the statistical design was performed in a factorial scheme (3:2) with three culture media (MS, WPM [4] and JADS, with 1.11µM BA) and two subcultures (28 and 56 days after the initial culture period). The analyzed variables for each subculture were: percentage of oxidation, of explants showing chlorosis, fresh weight and number of shoots. Results and discussion Regarding the oxidation, the higher rates (100%) were observed on JADS medium in presence or absence of PVP-40 and on MS-N/2 medium (68.3%) in presence of PVP-40. However, the JADS medium showed the highest percentage of callus formation (83.3%). In MS-N/2 medium the highest percentage of callus formation (55%) was found in the presence of PVP-40 and 0.5µM

Este trabalho teve como objetivo avaliar a divergencia genetica em clones da cana-de-acucar usando a metodologia de dispersao grafica por componentes principais associada aos modelos lineares mistos, identificando quais os genotipos mais divergentes e os mais produtivos de forma mais precisa, para posterior combinacao. Foram avaliados 138 clones de cana-de-acucar da Serie RB97 do Programa de Melhoramento Genetico de Cana-de-Acucar da Universidade Federal do Parana, mais duas variedades padroes, em tres ambientes, com duas repeticoes. Os dois primeiros componentes explicaram 96% da variacao total, sendo suficientes para explicar a divergencia encontrada. A caracteristica que mais contribuiu para a divergencia genetica foi quilograma de brix por parcela (KBP), seguida por brix, massa de 10 colmos (M10) e numero de colmos por parcela (NCP). Os clones mais divergentes foram RB975008, RB975112, RB975019, RB975153 e RB975067 e os clones mais produtivos foram RB975269, RB977533, RB975102, RB975317 e RB975038.

The objective of this work was to select the best sugarcane families to increase productivity (TCH) in T1 stage and monitor their performance in stages T2 and T3 of the sugarcane breeding program (PMGCA / UFPR / RIDESA). The experiments of stages T1 and T2 were performed at the experimental station of Paranavai (PR) and T3 stage was installed in three locations in the northwestern of Parana State. In the first phase (T1) 40 full-sib families from bi-parental crosses were evaluated and were correlated with selected families in the next stage of selection (T2), comparing the number of genotypes indicated by BLUPIS, and the number of clones that composed the T2 stage, by bulk selection. Data were analyzed by REML/BLUP methodology. In T1 stage, twenty and two (22) families were selected for T2 stage, and seven families were selected for T3 stage, being results of the crosses RB835486 x RB72454, SP70-1143 x RB855156, RB835054 x SP83-2847, SP80-3280 x RB835054, RB855156 x SP80-1816, SP80-3280 x RB855589, and SP80-3280 x RB835486. The BLUPIS selection procedure allowed the indication of a greater number of potential families and clones within these families. The genotypes with improved performance in subsequent phases were derived from families with positive genotypic values and yield above experimental average in the T1 stage.

The development of an efficient regeneration system is crucial for the genetic transformation of sugarcane. The aims of this study were to regenerate plants from somatic embryos and analyze the origin and division pattern of cells during the different embryonic developmental stages of the sugarcane cultivars RB855156 and RB72454. For both cultivars, the best results for embryogenic callus induction were obtained with explant cultures on culture medium containing 13.5 µM 2,4-dichlorophenoxyacetic acid (2,4-D) followed by callus culture on solid medium with 4.5 µM 2,4-D. A higher rate of shoot induction was observed in RB855156 with the addition of 8.9 and 17.8 µM benzylaminopurine (BAP); this higher rate was also observed in RB72454 with the addition of 17.8 µM BAP. Murashige and Skoog (1962) (MS) medium containing 2.5 and 5.0 µM indolebutyric acid (IBA) for RB855156 and RB72454, respectively, was suitable for rooting. The plantlets were successfully acclimatized and the plant survival rate was 100% for both cultivars. Histological analysis revealed that the shoots in both cultivars originated from somatic embryogenesis

Este trabalho teve como objetivo estudar o desenvolvimento radicular de cana-de-açúcar em dois sistemas de plantio, minitolete e tolete. O experimento foi realizado na Estação Experimental de Paranavaí, no município de Paranavaí-PR, Setor de Ciências Agrárias, Universidade Federal do Paraná, no período de 27 de junho de 2000 a 10 de julho de 2001. Foi utilizado delineamento em blocos ao acaso, com duas formas de plantio. Foram 9 épocas de avaliações durante o ciclo de 378 dias. A forma de plantio e a profundidade de amostragem não alteraram o comprimento e diâmetro radicular. Nos dois sistemas de plantio verificou-se que as variáveis superfície específica e volume radicular na camada 00-20 cm foram significativamente superiores. No sistema de plantio em minitolete, houve prioridade no crescimento radicular em profundidade, podendo ser uma característica importante para o desenvolvimento em condições de restrição hídrica.

O objetivo deste trabalho foi estimar parâmetros genéticos e selecionar clones de cana-de-açúcar na fase T3 no estado do Paraná, utilizando a metodologia REML/BLUP. O trabalho foi realizado em três ambientes de produção no Estado do Paraná (Colorado, Paranavaí e Mandaguaçú), em fase T3 com 236, 243 e 202 clones, respectivamente, e duas variedades padrões (RB72454 e RB835486). O experimento foi em blocos aumentados com duas repetições, sendo a variável analisada toneladas de brix por hectare (TBH). Os clones foram selecionados via modelos mistos, utilizando o critério MHPRVG (média harmônica da performance relativa dos valores genéticos preditos). Os clones mais adaptados, estáveis e produtivos pela metodologia MHPRVG foram: RB9371, RB975245 e RB975316. O uso do critério MHVG (média harmônica dos valores genéticos) deve ser empregado com cautela quando se faz seleção para estabilidade e produtividade em experimentos desbalanceados, isto é, quando todos os clones não estão presentes em todos os ambientes testados.

O objetivo deste trabalho foi avaliar a adaptabilidade e a estabilidade fenotípica de clones precoces de cana-de-açúcar em 11 locais no estado do Paraná durante 3 safras (33 ambientes). Os locais de instalação dos experimentos foram: Jandaia do Sul, São Pedro do Ivaí, São Tomé, Nova Londrina, Rondon, Jussara, Ibaití, Cidade Gaúcha, Bandeirantes, Paranavaí e lguatemi. Foram utilizados 18 clones precoces RB e duas variedades padrões (RB855156 e RB855453). As unidades experimentais foram compostas por parcelas úteis de quatro sulcos de 8 m, espaçados entre si por 1,40 m; sendo o delineamento utilizado o de blocos ao acaso com 3 repetições. A variável utilizada foi tonelada de pol por hectare (TPH) e o método de avaliação da adaptabilidade e estabilidade foi por análise não-paramétrica. O coeficiente de determinação genotípica para o caráter avaliado foi de alta magnitude (70%). Na série estudada os clones mais estáveis e produtivos foram RB925211, RB946903 e RB956911 tanto para ambientes favoráveis como desfavoráveis. Alguns clones apresentaram adaptação específica para ambientes favoráveis ou para ambientes desfavoráveis.

O objetivo deste trabalho, selecionar famílias superiores de cana-de-açúcar oriundas de cruzamentos biparentais, para produção de biomassa via modelos mistos. Adotou-se a metodologia REML/BLUP, onde o REML permitiu estimar a variância genética e o BLUP a estimar os valores genéticos das famílias utilizadas no presente estudo. Foram utilizadas 80 famílias originadas de cruzamentos biparentais da série RB03, provenientes de cruzamentos realizados na Estação de Cruzamentos Serra do Ouro, Município de Murici, Alagoas, no ano de 2003. O trabalho foi conduzido em área experimental, localizada no Município de São Tomé, Paraná. O delineamento estatístico do experimento foi em blocos incompletos, com cinco repetições por família. Cada parcela foi composta de dez plantas. Para seleção das famílias superiores adotou-se a produção de biomassa expressa em tonelada de cana por hectare (TCH). De acordo com os resultados obtidos, verificou-se que a herdabilidade individual () apresentou média magnitude (0,22), enquanto que em nível de famílias a herdabilidade média das famílias () foi alta magnitude (0,73). Ao realizar a seleção das famílias com valores genotípicos acima da média experimental, estima-se ganhos significativos para TCH. Sendo que as cinco melhores famílias para TCH foram originadas dos cruzamentos biparentais RB825336 e SP80-1816, RB825548 e RB855156, SP80-3280 e RB845257, RB83102 e RB855113, RB8495 e RB835089.