Search

A insegurança alimentar aumentou com o passar do tempo, aliada à contaminação, à degradação ambiental e ao declínio da saúde dos seres humanos. Isso mostra que os moldes convencionais de agricultura não são sustentáveis nem viáveis, seja pensando em um viés ecológico ou social. O objetivo do estudo foi apresentar o estado da arte sobre a utilização de Plantas Alimentícias Não Convencionais – Panc, em sistemas agroecológicos e a sua relação com o fortalecimento da soberania e segurança alimentar e nutricional. Para isso, realizou-se uma revisão bibliográfica narrativa, sendo os dados coletados nas plataformas SciELO, periódicos CAPES e Web of Science. De forma complementar o site Google Scholar®, trabalhos acadêmicos (dissertações e teses) e relatórios da FAO (Food and Agriculture Organization of the United Nations). Verificou-se que a agroecologia vista como uma ciência, e apta a alicerçar uma transição a modelos de agricultura sustentáveis, vem contribuindo para o desenvolvimento rural sustentável. Um dos objetivos da agroecologia é a busca pela utilização crescente de uma maior diversidade de plantas que, além da finalidade alimentícia, representam alternativa de subsistência para comunidades rurais e que, também, possam contribuir com a economia da região, tais como as Panc. O estudo também reforça que a produção de Panc em sistemas de base agroecológica tende a contribuir com a segurança alimentar, uma vez que se tratam de sistemas sustentáveis e preocupados com o meio ambiente e a nutrição, assegurando a distribuição de alimentos acessíveis e nutritivos, gerenciando os recursos naturais de maneira a preservar os ecossistemas.

Climate change alters regular weather seasonality. Corn is one of the main crops affected by irregular water regimes. Due to complications in decision-making processes related to climate change, it is estimated that planting corn outside the optimal window results in around USD 340 million in losses per year in the United States’ Corn Belt. In turn, exogenous plant growth regulators have been gaining prominence due to their potential to positively influence the morphology and physiology of plants under stress. This study was based on the hypothesis that the use of plant growth regulators can assist in mitigating the adverse effects of climate change on corn plants sown both inside and outside the recommended planting period. In this context, the effects of biostimulant application on gas exchange in corn plants sown within and outside the recommended period were evaluated. The experiment was carried out in randomized blocks in a 4 × 5 × 2 factorial scheme with four repetitions. These were four sowing times, the application of the biostimulants via seeds in five doses, and foliar applications (presence and absence). The biostimulant doses were 0.00, 6.25, 12.50, 18.75, and 25 mL kg−1. The foliar application used a dose of 500 mL ha−1. Only in the period (2017/2) higher doses of biostimulants indicated a decrease in the water use efficiency of plants, suggesting the need to evaluate this variable carefully. In this regard, future studies may investigate the ideal doses and application timings of biostimulants for different edaphoclimatic conditions. In general, the combined use of biostimulants on seeds and as a foliar treatment boosted physiological activity and stimulated photosynthetic processes in corn plants. Based on these data, plant regulators can be a useful tool to mitigate the adverse effects of climate change on corn plants sown inside and outside the planting period.

Sugarcane harvesting requires improvements, particularly in cutting tools. Continuous cutting saws have been introduced as a solution to this issue. This study evaluates the performance of two basal sugarcane cutting systems in different fields: a traditional impact cut system (ICS) with knives and a continuous cut system (CCS) with saw blades. Tests were conducted during two crop cycles in three areas, using a 3 × 2 factorial design with two cutting devices and four replications per treatment. Cut quality indices and ratoon damage were analyzed using descriptive statistics. Raw material losses were subjected to the Shapiro–Wilk normality test, ANOVA, and Tukey’s test at 5% probability. Significant differences in cutting quality were found across different areas. The total crop productivity influenced sugarcane cut quality, with the CCS showing (0.8 Mg ha−1) visible losses in higher productivity areas, which is a 74% increase compared to the ICS. In lower productivity areas, the CCS demonstrated better loss performance (0.8 Mg ha−1). Additionally, the stumps damage rate for the CCS was lower than that for the ICS (0.15 and 0.28, respectively), indicating that saws can preserve cane fields and enhance longevity.

Drought stress consists of a significant productivity constraint in tomatoes. Two contrasting crosses were performed to estimate physiological and morphological traits in response to drought stress during the vegetative stage, aiming to identify superior genotypes for drought tolerance. Two genotypes (GBT_2037 – sensitive drought-sensitive and GBT_2016 – intermediate drought-tolerant) were used as female parentals, and a commercial hybrid (drought tolerant) was used as a pollen source in both crosses: C1 (GBT_2037 × Commercial hybrid) and C2 (GBT_2016 × Commercial hybrid). The populations of parentals (P), the first generation of descendants (F1), backcrosses (BC), and the second generation of self-pollination (F2) were exposed to drought stress for 20 days when they were analyzed: physiological traits (relative water content of leaves, proline, and relative chlorophyll content) and morphological (plant height, stem diameter, number of leaves, fresh and dry matter of roots and shoot and classification by wilt scale). The means of chlorophyll, root/shoot ratio, and water content in leaves for the F2 generation of C2 were higher than C1, indicating that C2 resulted in plants with greater capacity to maintain turgor under conditions of water stress and presented minor damage to the photosynthetic structures, consequently showing greater tolerance to drought stress.

The high sensitivity of beans to herbicides is one of the limiting factors regarding the management of dicot weeds in bean crops. Protoporphyrinogen oxidase (PPO) inhibition is an important mechanism of action that has unregistered molecules with potential use in bean crops. The objectives of this study were to investigate the tolerance of Brazilian bean cultivars to distinct PPO inhibitors and to determine the existence of cross-tolerance in cultivars to the different PPO inhibitor chemical groups. In the first and second experiments, the BRSMG Talismã, Jalo Precoce, BRS Esplendor, and IPR 81 cultivars were subjected to saflufenacil doses pre- (0, 9.6, 14.1, 20.5, 30.0, and 43.8 g a.i. ‧ ha–1) and post-emergence (0, 0.7, 1.0, 1.5, 2.1, and 3.1 g a.i. ‧ ha–1). In the third experiment, the tolerance of 28 bean genotypes to saflufenacil (20.5 g a.i. ‧ ha–1) in pre-emergence was determined. In the fourth, fifth, sixth and seventh experiments, we investigated the cross-tolerance of bean to the fomesafen, flumioxazin, sulfentrazone, and saflufenacil herbicides, respectively. Even very low saflufenacil doses in post-emergence caused plants of all cultivars to die rapidly; therefore, the tolerance was much lower at this application time than in pre-emergence. There was high tolerance variability to saflufenacil among the 28 cultivars. The bean tolerance to fomesafen, flumioxazin, sulfentrazone, and saflufenacil applied pre-emergence depended on the cultivar and dose. Fomesafen was highlighted owing to its higher selectivity in relation to the different cultivars. No cross-tolerance pattern to the PPO inhibitor chemical groups applied in pre-emergence was observed among the evaluated bean cultivars. The results of this study could be of significance to farmers and technical assistance personnel, as well as for future research on cultivar breeding and the elucidation of biochemical and genetic mechanisms involved in herbicide tolerance.

Euphorbia heterophylla populations endued with resistance to both imazethapyr (an acetolactate synthase inhibitor) and fomesafen (a protoporphyrinogen oxidase inhibitor) were first detected in Brazil in 2004. The objectives of this study were to determine the number and dominance of genes conferring imazethapyr and fomesafen resistance in E. heterophylla and to establish the types of inheritance of the resistance traits. It was hypothesised that two dominant nuclear genes control this herbicide resistance and each gene confers resistance to a single herbicide. We crossed a susceptible (S) and a multiple‐resistant (R) E. heterophylla biotype and generated F₁ families which, in turn, were self‐fertilised to produce F₂ families. Backcrosses of the F₁ families with the S‐ and R parental biotypes resulted in BCₛ and BCᵣ families respectively. The F₁, F₂, BCₛ and BCᵣ families and the S and R parental biotypes were subjected to imazethapyr and fomesafen wherein each herbicide was used as a selecting agent. F₁ plants and the S‐ and R parental biotypes were used to evaluate the dominance of the resistance trait in multiple‐dose bioassays with imazethapyr and fomesafen. The observed frequencies of resistant plants in the F₁, F₂, BCₛ and BCᵣ families did not significantly differ from the expected frequencies for a resistance trait regulated by two dominant genes in which each gene confers resistance to a single herbicide. The lack of difference in herbicide response between the F₁ family and the R parental biotype was taken as evidence for completely dominant resistance to imazethapyr and fomesafen. Herbicide resistance in E. heterophylla presents with dominant monogenic nuclear inheritance for each herbicide mode of action. Our findings underscore the necessity and urgency of adopting integrated strategies to control E. heterophylla and to inhibit the evolution of new herbicide‐resistant strains.

Grain size is an essential trait in common bean breeding as it determines the acceptance of a new cultivar by producers, consumers, and the industry. The objectives of this study were to identify the ideal traits for selecting common bean lines in the F3 generation to obtain an adequate sieve yield and to identify the best lines for sieve yield by applying early generation selection. Two trials were conducted in two locations during the 2016/2017 crop season. These trials were composed of 300 F3 populations and two parents (used as checks). The experimental design used was an augmented block design without repetition for the treatments (lineages). After harvest, the grain yield, yield components, and sieve yield (SY) were evaluated. In conclusion, selection in the F3 generation can be performed for sieve yield, considering the traits SY12+13, SY14, and relative grain yield, as they present the highest values of heritability and greatest correlation between genotype and performance in the evaluated environments. Additionally, the lines selected to continue in the breeding program are composed of the 15 best lineages for traits SY12+13, SY14, and relative grain yield. Preference should be given to lines that excel in more than one of these traits. Grain size is an essential trait in common bean breeding as it determines the acceptance of a new cultivar by producers, consumers, and the industry. The objectives of this study were to identify the ideal traits for selecting common bean lines in the F3 generation to obtain an adequate sieve yield and to identify the best lines for sieve yield by applying early generation selection. Two trials were conducted in two locations during the 2016/2017 crop season. These trials were composed of 300 F3 populations and two parents (used as checks). The experimental design used was an augmented block design without repetition for the treatments (lineages). After harvest, the grain yield, yield components, and sieve yield (SY) were evaluated. In conclusion, selection in the F3 generation can be performed for sieve yield, considering the traits SY12+13, SY14, and relative grain yield, as they present the highest values of heritability and greatest correlation between genotype and performance in the evaluated environments. Additionally, the lines selected to continue in the breeding program are composed of the 15 best lineages for traits SY12+13, SY14, and relative grain yield. Preference should be given to lines that excel in more than one of these traits.

Molecular markers are largely used to assist in crop improvement with the aim to achieve more favorable results in reduced time. In this study, we applied scientometric approaches to investigate and describe the application of molecular markers in genetic studies of common bean (Phaseolus vulgaris L.). A total of 671 articles, available on Thomson Reuters Web of Science database, published between 1991 and 2020, were analyzed, and it was determined that the USA and Brazil have the highest number of publications related to this subject. The main topics where molecular markers were used in common beans were fingerprinting, genetic diversity assessment, mapping, molecular marker development, marker-assisted selection, comparative genomics or evolution, and marker-trait association. They were also used to solve problems related to anthracnose (Colletotrichum lindemuthianum) and agronomic traits. As the genome sequence of common bean has been publicly available since 2014, SNP markers are frequently employed and their use is increasing, whereas other molecular markers are being bypassed.

In this study, we aim to develop and validate KASP molecular markers in soybean populations for Asian soybean rust (ASR) resistance gene Rpp1 (PI 200492, PI 594538A, PI 587880A), identify the gene hypothetically present in PI 594723, and validate KASP markers for Rpp2 (PI 230970), Rpp3 (PI 506764), Rpp4 (PI 459025A), and Rpp5 (PI 506764, PI 200487). Ten F2 soybean (Glycine max (L.) Merrill) populations derived from crosses between rust-susceptible (55I57RSF IPRO, 63I64RSF IPRO) x rust-resistant sources (PI 200492, PI 594738A, PI 587880A, PI 594723, PI 230970, PI 506764, PI 459025A and PI 200487) were evaluated. All F2 plants were individually evaluated in field conditions for ASR phenotypic reactions, classified according to sporulation level. SNP markers were developed according to markers associated with Rpp genes available at the SoyBase, using KASP methodology. Based on a slight difference in map position and different phenotypic disease reactions of PI 200492, the authors suggest that PI 594723 carries a resistance gene Rpp1-b. The Rpp1-b gene from PI 594723 was mapped in Chr 18 in a 12.4 cM region. The PIs carrying Rpp1-b (PI 594723, PI 587880A, and 594538A) showed strong resistance to ASR compared to the lines carrying Rpp1 (PI 200492). A total of 26 KASP markers were significantly associated (P Rpp1), M13 and M14 (Rpp2), M16, M17 and M20 (Rpp3), M25 and M26 (Rpp4), and M27 and M28 (Rpp5) have the potential to be used in marker-assisted selection strategies.

The objective of this work was to evaluate the grain yield and stability of common bean genotypes, as well as the representativeness and discrimination ability of locations in multi-environment trials (METs), using the GGE biplot analysis. The grain yield of 27 genotypes was evaluated in 16 trials carried out in nine locations, in the state of Santa Catarina, Brazil, during the first and second crop seasons of 2014/2015 and 2015/2016. A randomized complete block design with three replicates was used. As the trials were neither conducted in all locations, nor in all growing seasons of both years, a highly unbalanced dataset was used. Genotype 5 (CHC 01-175-1) was the most productive and stable, common bean genotype and can be considered the closest one to the ideal for the target region. Furthermore, this genotype performs well in both crop seasons, outperforming all the evaluated checks; therefore, it has the potential to be released as a new cultivar. Chapecó can be considered the ideal location for the selection of common bean genotypes, in the state of Santa Catarina, since it shows high representativeness and discrimination ability in the rainy and dry crop seasons. Resumo: O objetivo deste trabalho foi avaliar o rendimento de grãos e a estabilidade de genótipos de feijão, além da representatividade e da discriminância de locais em ensaios multiambientes, por meio de análises GGE biplot. O rendimento de grãos de 27 genótipos foi avaliado em 16 ensaios, realizados em nove locais do estado de Santa Catarina, Brasil, na primeira e na segunda safras de 2014/2015 e 2015/2016. Utilizou-se um delineamento experimental de blocos ao acaso, com três repetições. Como os testes não foram realizados em todos os locais nem em todas as estações de cultivo de ambos os anos, um conjunto de dados altamente desbalanceado foi usado. O genótipo 5 (CHC 01-175-1) foi o mais produtivo e estável, e pode ser considerado o mais próximo ao ideal para a região-alvo. Além disso, esse genótipo apresentou desempenho satisfatório tanto para a primeira quanto para a segunda safras, tendo superado o desempenho de todas as testemunhas utilizadas nos ensaios; portanto, esse genótipo tem potencial para ser lançado como uma nova cultivar. Chapecó pode ser considerado o local ideal de seleção de genótipos de feijão, no estado de Santa Catarina, pois apresenta elevada discriminância e representavidade, tanto para primeira quanto para a segunda safra.

The objective of this study was to evaluate the effect of acibenzolar-S-methyl (ASM) and harpin protein, applied pre-harvest, in the induction of resistance in strawberry to pathogens and mites. The experiment was conducted in a greenhouse, in a randomized block design with three replications. Treatments with harpin protein and ASM were established through biweekly applications of these elicitors in plants of strawberry, from 60 to 120 days after transplanting of seedlings. The application of ASM and harpin protein induced resistance in the strawberry plants, resulting in an increase in phenylalanine ammonia-lyase activity and total phenol production, while reducing leaf blight and grey mould. The application of harpin protein also caused a reduction in mite damage, while increasing photosynthetic rate and the production of marketable fruits. The elicitors ASM and harpin, applied pre-harvest, can be used as part of the integrated pest management of diseases and pests of strawberry.

Genomic selection (GS) can potentially accelerate genetic improvement of soybean [Glycine max L. (Merrill)] by reducing the time to complete breeding cycles. The objectives of this study were to (1) explore the accuracy of GS in soybean, (2) evaluate the contribution of intrapopulational structure to the accuracy of GS, and (3) compare the efficiencies of phenotypic selection and GS in soybean. For this, phenotypic and genotypic data were collected from 324 soybean genotypes (243 recombinant inbred lines and 81 cultivars) and GS was performed for five yield related traits. BayesB methodology with a 10-fold cross-validation was used to compute accuracies. The GS accuracies were evaluated for grain yield, plant height, insertion of first pod, days to maturity, and 1000-grain weight at eight locations. We found that GS can reduce the time required to complete a selection cycle in soybean, which can lead to increased production of this commercially important crop. Furthermore, genotypic accuracy was similar regardless of population structure correction.

Apple is commercially important worldwide. Favorable genomic contexts and postharvest technologies allow year-round availability. Although ripening is considered a unidirectional developmental process toward senescence, storage at low temperatures, alone or in combination with ethylene blockage, is effective in preserving apple properties. Quality traits and genome wide expression were integrated to investigate the mechanisms underlying postharvest changes. Development and conservation techniques were responsible for transcriptional reprogramming and distinct programs associated with quality traits. A large portion of the differentially regulated genes constitutes a program involved in ripening and senescence, whereas a smaller module consists of genes associated with reestablishment and maintenance of juvenile traits after harvest. Ethylene inhibition was associated with a reversal of ripening by transcriptional induction of anabolic pathways. Our results demonstrate that the blockage of ethylene perception and signaling leads to upregulation of genes in anabolic pathways. We also associated complex phenotypes to subsets of differentially regulated genes. KEYWORDS: 1-methylcyclopropene, firmness, fruit quality, gene expression, microarray Made available in DSpace on 2017-12-20T23:18:02Z (GMT). No. of bitstreams: 1 Storch2017applemicroarray.pdf: 6164592 bytes, checksum: 670637e0b5b4b2cd4b81c033c1c0b2e2 (MD5) Previous issue date: 2017-10-20

WRKY transcription factors (TFs) are responsible for the regulation of genes responsive to many plant growth and developmental cues, as well as to biotic and abiotic stresses. The modulation of gene expression by WRKY proteins primarily occurs by DNA binding at specific cis-regulatory elements, the W-box elements, which are short sequences located in the promoter region of certain genes. In addition, their action can occur through interaction with other TFs and the cellular transcription machinery. The current genome sequences available reveal a relatively large number of WRKY genes, reaching hundreds of copies. Recently, functional genomics studies in model plants have enabled the identification of function and mechanism of action of several WRKY TFs in plants. This review addresses the more recent studies in plants regarding the function of WRKY TFs in both model and crop plants for coping with environmental challenges, including a wide variety of abiotic and biotic stresses.

Drought stress on reproductive stages constitute a major problem for common bean (Phaseolus vulgaris L.) production because it affects flowering and pod-filling processes which are highly drought-sensitive. In this study, we used a greenhouse experiment to evaluate the response to drought stress in ten highly cultivated Brazilian genotypes in response to moderate intermittent drought during flowering and pod-filling periods (R7 and R8 stages). Morphological, biochemical, physiological and agronomic traits were used to identify tolerant cultivars and elucidate their strategies to cope this stress. The drought intensity index for the experiment reached 0.63. The cultivar IAC Imperador can be defined as a tolerant cultivar, presenting the lowest grain yield reduction (43%) and a reduced drought susceptibility index (0.65). This cultivar elevated their level of proline in roots under stress, which allowed the osmotic adjustment and the maintenance of an intermediate stomata closure during the day, which maintained the intrinsic WUE stable in NS and DS conditions. In addition, this cultivar was able to mobilize the assimilated carbon for the production of pods and grains, evidenced by the high harvest index and the high grain filling index. In this way, IAC Imperador can be used as a check in breeding programs to identify and select lineages with drought tolerance in common bean.

Iron (Fe) is an essential microelement for all living organisms playing important roles in several metabolic reactions. Rice (Oryza sativa L.) is commonly cultivated in paddy fields, where Fe goes through a reduction reaction from Fe3+ to Fe2+. Since Fe2+ is more soluble, it can reach toxic levels inside plant cells, constituting an important target for studies. Here we aimed to verify morphological changes of different rice genotypes focusing on deciphering the underlying molecular network induced upon Fe excess treatments with special emphasis on the role of four WRKY transcription factors. The transcriptional response peak of these WRKY transcription factors in rice seedlings occurs at 4 days of exposition to iron excess. OsWRKY55-like, OsWRKY46, OsWRKY64, and OsWRKY113 are up-regulated in BR IRGA 409, an iron-sensitive genotype, while in cultivars Nipponbare (moderately resistant) and EPAGRI 108 (resistant) the expression profiles of these transcription factors show similar behaviors. Here is also shown that some cis-regulatory elements known to be involved in other different stress responses can be linked to conditions of iron excess. Overall, here we support the role of WRKY transcription factors in iron stress tolerance with other important steps toward finding why some rice genotypes are more tolerant than others.

The nitrogen use efficiency (NUE) is defined as the capacity of a given genotype in take advantage of the applied nitrogen (N) and transform it in biomass and grains. The objective of this study was to evaluate 12 wheat cultivars as to the NUE and its components. The experiment was conducted in a controlled environment, in a randomized block design with three replications. Twelve wheat cultivars were submitted to four N supply levels (0, 80, 160 and 240 kg of N∙ha–1). The data were submitted to analysis of variance, means multiple comparison, polynomial regression, and path analysis. The nitrogen remobilization efficiency (NRE) was the main NUE component of the evaluated cultivars, in both low and high conditions of nitrogen fertilization. In the cultivars average, the nitrogen utilization efficiency (NUtE) presented reduction tendency as the N supply was increased, tending to stabilization at the dose of 231 kg of N∙ha–1. The wheat cultivars Mirante, TBIO Itaipu, BRS Parrudo, and TBIO Iguaçu were the most efficient on the N use, and the first two were also efficient in remobilizing the N from the phytomass to the grains. RESUMO A eficiência de uso do Nitrogênio (EUN) é definida como a capacidade de determinado genótipo em aproveitar o Nitrogênio (N) aplicado e transformá-lo em fitomassa e grãos. O objetivo deste estudo foi avaliar 12 cultivares de trigo quanto à EUN e seus componentes. O experimento foi conduzido em ambiente controlado, em delineamento de blocos ao acaso, com três repetições. Doze cultivares de trigo foram submetidas a diferentes doses de N (0, 80, 160 e 240 kg de N∙ha–1). Os dados foram submetidos a análise de variância, comparação múltipla de médias, regressão polinomial e análise de trilha. A eficiência de remobilização do Nitrogênio (ERN) foi o principal componente da EUN das cultivares avaliadas, tanto na condição de baixa quanto na de alta oferta de adubação nitrogenada. Na média das cultivares, a eficiência de utilização do Nitrogênio (EUtN) apresentou tendência de redução à medida que se elevou a oferta de N, tendendo à estabilização na dose de 231 kg de N∙ha–1. As cultivares de trigo Mirante, TBIO Itaipu, BRS Parrudo e TBIO Iguaçu foram as mais eficientes no uso do N, e as duas primeiras também foram eficientes em remobilizar o N da fitomassa para os grãos.

O emprego do cultivo hidropônico para avaliar a tolerância à toxicidade pelo alumínio em genótipos de aveia pode ser feito por meio da medida da retomada do crescimento de raiz. Avaliaram-se 12 cultivares de aveia branca indicadas para o cultivo no Sul do Brasil com o intuito de caracterizar a tolerância ao alumínio, de maneira a ser estrategicamente recomendadas e/ou incluídas em blocos de cruzamento na obtenção de constituições genéticas de elevado potencial produtivo e tolerante ao íon metálico. Foram utilizadas doses de 10, 15 e 20 mg L-1 de alumínio na solução hidropônica e o delineamento experimental adotado foi o completamente casualizado, com três repetições, seguindo o esquema fatorial (12 x 3). As doses empregadas são altamente eficientes na identificação de genótipos de aveia tolerantes e sensíveis ao alumínio tóxico. As cultivares UPF 16, URS 21, UFRGS 14, UPF 19 e UFRGS 17 expressam tolerância.The use of hidroponic culture to evaluate tolerance to aluminum toxicity in oat genotypes can be performed by measuring root regrowth, allowing phenotypically to discriminate tolerant genetic constitutions sensitivity. Twelve white oat cultivars indicated for cultivation in Southern Brazil were evaluated aiming at to characterize their aluminum tolerance, in order to use them as parents in crosses or to recommend them for in cultivation regions. Aluminum concentration of 10, 15 and 20 mg L-1 were used in the hydroponic solution arranged in complete randomized blocks with three replications in 12 x 3 factorial designs. Concentrations of 10, 15 and 20 mg L-1 were highly efficient for the identification of tolerant and sensitive oat genotypes. Cultivars UPF 16, URS 21, UFRGS 14, UPF 19 and UFRGS 17 showed aluminum.

Conhecer como os caracteres agronômicos se correlacionam nas populações segregantes é primordial ao melhorista de plantas, principalmente quando o objetivo for seleção indireta, por meio de um caráter de fácil mensuração ou de maior herdabilidade correlacionado ao caráter de interesse de menor herdabilidade. Dessa forma, a partir da variabilidade observada em caracteres agronômicos nas gerações F2 e F3 de quatro cruzamentos de trigo, avaliados no ano agrícola de 2004, no Centro Agropecuário da Palma, do Centro de Genômica e Fitomelhoramento - FAEM/UFPel, localizado no município de Capão do Leão (RS), este trabalho teve como objetivos estimar: a) coeficientes de correlação genotípica, fenotípica e de ambiente entre os caracteres; b) coeficientes de trilha sobre o rendimento de grãos. Em todas as populações avaliadas, por meio das correlações simples, a seleção de plantas mais produtivas pode ser realizada pela seleção indireta sobre número de afilhos férteis por planta. Mediante a análise de trilha foi possível identificar o efeito indireto do caráter número de afilhos férteis como causador da formação da correlação entre outros caracteres (comprimento da espiga x rendimento de grãos, número de espiguetas da espiga x rendimento de grãos e número de grãos da espiga x rendimento de grãos), enfatizando que o número de afilhos férteis é o principal caráter a ser considerado na obtenção de ganhos em produção por planta. The knowledge of how the agronomical traits are correlated in segregating populations is of primary importance for plant breeders, specially when one considers indirect selection through a character easily measurable or with high heritability correlated to the trait of interest with lower heritability. Agronomical traits in F2 and F3 generations of four wheat crosses, were evaluated on 2004 agricultural year in the Centro Agropecuário da Palma, of the Centro de Genômica e Fitomelhoramento - FAEM/UFPel, located in Capão do Leão country in Rio Grande do Sul State. The present work had the objectives to estimate for evaluated traits: a) genotypic, phenotypic and environmental correlation coefficients between the traits; and b) path coefficients for grain yield. For all populations, the single correlations indicated that the selection of higher yielding plants can be performed by indirect selection for number of fertile tillers per plant. The path analysis showed that it was possible to identify the indirect effect of the trait number of fertile tillers the as cause of the correlation between other traits (ear length x grain yield, spikelet number per ear x grain yield and number of ear grain x grain yield). Thus suggesting that the number of fertile tillers is the major trait to select for in order to obtain gains on grain yield.

Conhecer como os caracteres agronômicos se correlacionam nas populações segregantes é primordial ao melhorista de plantas, principalmente quando o objetivo for seleção indireta, por meio de um caráter de fácil mensuração ou de maior herdabilidade correlacionado ao caráter de interesse de menor herdabilidade. Dessa forma, a partir da variabilidade observada em caracteres agronômicos nas gerações F2 e F3 de quatro cruzamentos de trigo, avaliados no ano agrícola de 2004, no Centro Agropecuário da Palma, do Centro de Genômica e Fitomelhoramento - FAEM/UFPel, localizado no município de Capão do Leão (RS), este trabalho teve como objetivos estimar: a) coeficientes de correlação genotípica, fenotípica e de ambiente entre os caracteres; b) coeficientes de trilha sobre o rendimento de grãos. Em todas as populações avaliadas, por meio das correlações simples, a seleção de plantas mais produtivas pode ser realizada pela seleção indireta sobre número de afilhos férteis por planta. Mediante a análise de trilha foi possível identificar o efeito indireto do caráter número de afilhos férteis como causador da formação da correlação entre outros caracteres (comprimento da espiga x rendimento de grãos, número de espiguetas da espiga x rendimento de grãos e número de grãos da espiga x rendimento de grãos), enfatizando que o número de afilhos férteis é o principal caráter a ser considerado na obtenção de ganhos em produção por planta.The knowledge of how the agronomical traits are correlated in segregating populations is of primary importance for plant breeders, specially when one considers indirect selection through a character easily measurable or with high heritability correlated to the trait of interest with lower heritability. Agronomical traits in F2 and F3 generations of four wheat crosses, were evaluated on 2004 agricultural year in the Centro Agropecuário da Palma, of the Centro de Genômica e Fitomelhoramento - FAEM/UFPel, located in Capão do Leão country in Rio Grande do Sul State. The present work had the objectives to estimate for evaluated traits: a) genotypic, phenotypic and environmental correlation coefficients between the traits; and b) path coefficients for grain yield. For all populations, the single correlations indicated that the selection of higher yielding plants can be performed by indirect selection for number of fertile tillers per plant. The path analysis showed that it was possible to identify the indirect effect of the trait number of fertile tillers the as cause of the correlation between other traits (ear length x grain yield, spikelet number per ear x grain yield and number of ear grain x grain yield). Thus suggesting that the number of fertile tillers is the major trait to select for in order to obtain gains on grain yield.

Fruit texture changes impair the quality of apples submitted to long term storage, especially under cold. The changes are due to cell wall modifications during ripening and senescence and are associated to ethylene. We have investigated the activity of alpha-L-arabinofuranosidase, a glycosyl hydrolase acting on the side chains of pectin in the cell wall and middle lamella. The transcription of arabinofuranosidase coding sequences 1 and 3 was investigated in plant organs and in response to ethylene, employing hormone application and 1-methylcyclopropene. The transcription of arabinofuranosidase genes is not restricted to fruits, although upregulated by ripening and ethylene. Transcripts of the genes were detected under cold storage up to 180 days. Similarly, arabinofuranosidase activity increased with rising levels of ethylene and under cold storage. Levels of ARABINOPURANOSIDASE3 transcripts were higher than those of ARABINOFURANOSIDASE1 suggesting that the first is an important contributor to enzyme activity and texture changes during cold storage.

http://dx.doi.org/10.5007/1807-0221.2016v13n21p132Com a necessidade de buscar alternativas para a produção de um alimento mais saudável e com baixo nível de toxicologia tanto para as pessoas como para o meio ambiente. As chamadas caldas e fertilizantes orgânicos vêm com esse propósito, na qual são utilizadas na agricultura orgânica. Com este intuito as oficinas objetivaram levar aos agricultores técnicas de preparo e uso da calda bordalesa e sulfocálcica para o controle de insetos e doenças, bem como a produção de fertilizante orgânico, por meio do processo de compostagem. Realizada em assentamentos rurais no município de Itapiúna no Ceará para agricultores rurais, levou informações que podem utilizar tranquilamente em suas propriedades, principalmente por se tratar de fácil execução e com baixo custo, tanto as caldas como a compostagem, houve grande interesse pela aprendizagem por parte dos agricultores.

A estimativa da distância genética entre cultivares pode ser útil em um programa de melhoramento para o direcionamento de hibridações e no conhecimento do germoplasma disponível. O objetivo do presente trabalho foi o de estimar a distância genética entre as constituições genéticas de trigo adaptadas para a região Sul do Brasil de modo a apontar combinações promissoras com genótipos que expressam o caráter "stay-green". Foram avaliados 37 genótipos de trigo em campo experimental e mensurados quatorze caracteres morfológicos. Os métodos de agrupamento com base nas técnicas de Tocher, MDS e UPGMA foram eficientes para discriminar a distância genética entre os genótipos testados. O direcionamento de hibridações com linhagens de trigo do tipo de maturação "stay-green", de elevado potencial de rendimento, com cultivares elite pode fornecer populações promissoras na obtenção de genótipos superiores. Estimates of genetic distance among cultivars can be useful in an improvement program for directing crosses and evaluating the available germoplasm. This work was aimed at estimating the genetic distance among the genetic constitutions of wheat adapted in the South of Brazil in order to verify promising combinations with genotypes that express the stay-green trait. 37 wheat genotypes were evaluated in experimental field and measured fourteen morphological characters. The clustering methods based on the techniques of Tocher, MDS and UPGMA were efficient to discriminate the genetic distance among the tested genotypes. Directed crosses between high yield stay-green wheat lines and elite cultivars can provide promising populations for obtaining superior genotypes.

O melhoramento de plantas tem por base a ampliação da variabilidade genética existente através de cruzamentos artificiais planejados. Assim, é de fundamental importância o conhecimento das populações formadas, a fim de prever o potencial das combinações a partir de diferentes genitores, permitindo maior eficiência de seleção para o caráter desejado, otimizando o ganho genético. Dessa forma, o objetivo deste trabalho foi o de observar a variabilidade fenotípica dos caracteres estatura de planta, ciclo vegetativo e ciclo reprodutivo na geração F2 e prever as melhores combinações para a obtenção de constituições genéticas superiores. Para isso, cinco genótipos de aveia (UPF 16, UPF 18, UFRGS 7, UFRGS 17 e URPEL 15) foram cruzados de forma dialélica, sem a realização dos cruzamentos recíprocos, para o desenvolvimento das populações F2. Para analisar a variabilidade nas populações, foram utilizados os parâmetros: média, variância e assimetria da distribuição de freqüência. Os cruzamentos UPF 16 x UFRGS 17 e UFRGS 17 x URPEL 15 produziram grande quantidade de plantas de estatura reduzida. Para o caráter ciclo vegetativo, UPF 16 x UPF 18, UPF 16 x UFRGS 7, UPF 16 x UFRGS 17, UPF 16 x URPEL 15, UFRGS 7 x UFRGS 17 e UFRGS 7 x URPEL 15 foram os cruzamentos que produziram descendentes de ciclo curto. UPF 16 x UFRGS 17 e UPF 16 x URPEL 15 produziram amplo número de progênies de ciclo reprodutivo longo. Plant breeding is based on the pursue of an amplification of genetic variability through planned crosses. Thus, it is of fundamental importance to study the formed populations, in order to predict the potential of different parental combinations, allowing a higher selection efficiency for the desired trait, optimizing genetics gains. Thus, the objective of this work was to observe the phenotypic variability of the characters plant stature, vegetative cycle and reproductive cycle in F2 generation and to predict the best combinations to obtain superior genetic constitutions. Therefore, five oat genotypes (UPF 16, UPF 18, UFRGS 7, UFRGS 17 and URPEL 15) were crossed in a diallelic format, without reciprocal crosses, for the development of F2 populations. To analyze population variability, the following parameters were used: mean, variance and asymmetry of frequency distribution. The crosses UPF 16 x UFRGS 17 and UFRGS 17 x URPEL 15 produced a large amount of plants with shorter stature. For the character vegetative cycle, UPF 16 x UPF 18, UPF 16 x UFRGS 7, UPF 16 x UFRGS 17, UPF 16 x URPEL 15, UFRGS 7 x UFRGS 17 and UFRGS 7 x URPEL 15 were the crosses that produced short cycle plants. UPF 16 x UFRGS 17 and UPF 16 x URPEL 15 produced a large number of long-cycled progenies.

O emprego do cultivo hidropônico para avaliar a tolerância à toxicidade pelo alumínio em genótipos de aveia pode ser feito por meio da medida da retomada do crescimento de raiz. Avaliaram-se 12 cultivares de aveia branca indicadas para o cultivo no Sul do Brasil com o intuito de caracterizar a tolerância ao alumínio, de maneira a ser estrategicamente recomendadas e/ou incluídas em blocos de cruzamento na obtenção de constituições genéticas de elevado potencial produtivo e tolerante ao íon metálico. Foram utilizadas doses de 10, 15 e 20 mg L-1 de alumínio na solução hidropônica e o delineamento experimental adotado foi o completamente casualizado, com três repetições, seguindo o esquema fatorial (12 x 3). As doses empregadas são altamente eficientes na identificação de genótipos de aveia tolerantes e sensíveis ao alumínio tóxico. As cultivares UPF 16, URS 21, UFRGS 14, UPF 19 e UFRGS 17 expressam tolerância. The use of hidroponic culture to evaluate tolerance to aluminum toxicity in oat genotypes can be performed by measuring root regrowth, allowing phenotypically to discriminate tolerant genetic constitutions sensitivity. Twelve white oat cultivars indicated for cultivation in Southern Brazil were evaluated aiming at to characterize their aluminum tolerance, in order to use them as parents in crosses or to recommend them for in cultivation regions. Aluminum concentration of 10, 15 and 20 mg L-1 were used in the hydroponic solution arranged in complete randomized blocks with three replications in 12 x 3 factorial designs. Concentrations of 10, 15 and 20 mg L-1 were highly efficient for the identification of tolerant and sensitive oat genotypes. Cultivars UPF 16, URS 21, UFRGS 14, UPF 19 and UFRGS 17 showed aluminum.

Reverse Transcription quantitative PCR (RT-qPCR) is one of the most important techniques for gene expression profiling due to its high sensibility and reproducibility. However, the reliability of the results is highly dependent on data normalization, performed by comparisons between the expression profiles of the genes of interest against those of constitutively expressed, reference genes. Although the technique is widely used in fruit postharvest experiments, the transcription stability of reference genes has not been thoroughly investigated under these experimental conditions. Thus, we have determined the transcriptional profile, under these conditions, of three genes commonly used as reference--ACTIN (MdACT), PROTEIN DISULPHIDE ISOMERASE (MdPDI) and UBIQUITIN-CONJUGATING ENZYME E2 (MdUBC)--along with two novel candidates--HISTONE 1 (MdH1) and NUCLEOSSOME ASSEMBLY 1 PROTEIN (MdNAP1). The expression profile of the genes was investigated throughout five experiments, with three of them encompassing the postharvest period and the other two, consisting of developmental and spatial phases. The transcriptional stability was comparatively investigated using four distinct software packages: BestKeeper, NormFinder, geNorm and DataAssist. Gene ranking results for transcriptional stability were similar for the investigated software packages, with the exception of BestKeeper. The classic reference gene MdUBC ranked among the most stably transcribed in all investigated experimental conditions. Transcript accumulation profiles for the novel reference candidate gene MdH1 were stable throughout the tested conditions, especially in experiments encompassing the postharvest period. Thus, our results present a novel reference gene for postharvest experiments in apple and reinforce the importance of checking the transcription profile of reference genes under the experimental conditions of interest.

A seleção indireta visando ao incremento no rendimento de grãos pelos seus componentes primários bem como a resistência ao acamamento podem representar estratégias eficientes a serem adotadas para otimização do ganho genético em trigo. Nesse sentido, o objetivo do trabalho foi evidenciar caracteres que possibilitem identificar genótipos de elevado rendimento de grãos e resistentes ao acamamento através de seleção indireta. O experimento foi conduzido no Centro Agropecuário da Palma, em Capão do Leão/RS, utilizando dezenove genótipos de trigo em delineamento de blocos ao acaso, com três repetições. Nas condições deste estudo, o peso hectolítrico pode ser empregado de maneira eficiente na seleção indireta, visando ao incremento no rendimento de grãos, no peso médio de grãos, número de grãos por espiga e no peso de espiga. O caráter peso de espiga evidenciou elevado efeito indireto sobre o rendimento de grãos, podendo ser empregado na seleção indireta pela facilidade de mensuração. A linhagem TB 951 é indicada como excelente fonte de resistência ao acamamento em trigo, podendo contribuir para elevar o comprimento de espiga, o número de espigueta por espiga, o peso de espiga e o número de grãos por espiga.

A ferrugem da folha da aveia é a moléstia mais importante que ataca a cultura da aveia, ocorrendo em praticamente todas as áreas em que a aveia é cultivada. A forma mais indicada para o seu controle é a utilização de cultivares resistentes. Contudo, para que seja alcançada a resistência durável ao patógeno, é necessário que se conheça a genética da resistência à ferrugem da folha em aveia. O objetivo foi determinar a forma de herança da resistência a três isolados de Puccinia coronata f. sp. avenae Fraser & Led., (coletados no sul do Brasil) em genótipos brasileiros de aveia branca. Para a determinação da herança da resistência a cada um dos três isolados, foram utilizadas populações F2 geradas por meio de cruzamentos artificiais, entre genótipos resistentes (R) e suscetíveis (S) e entre genótipos resistentes (R). Desta forma, foram utilizadas populações F2 dos cruzamentos artificiais entre: i) URPEL 15 (R) x UFRGS 7 (S), UPF 16 (R) x UFRGS 7 (S) e URPEL 15 (R) x UPF 16 (R), para a determinação da herança da resistência ao isolado um (1); ii) URPEL 15 (R) x UFRGS 7 (S), UPF 18 (R) x UFRGS 7 (S) e URPEL 15 (R) x UPF 18 (R), para a determinação da herança da resistência ao isolado dois (2); iii) URPEL 15 (R) x UFRGS 7 (S) e URPEL 15 (R) x UPF 18 (S), para a determinação da herança da resistência ao isolado três (3). Os resultados obtidos evidenciaram que o genótipo URPEL 15 apresenta genes dominantes de resistência aos três isolados de ferrugem da folha da aveia avaliados, que o cultivar UPF 16 apresenta um gene recessivo de resistência ao isolado 1 e o cultivar UPF 18 apresenta um gene recessivo de resistência ao isolado 2. E que os genes de resistência apresentados pelos genótipos URPEL 15, UPF 16 e UPF 18, segregam de forma independente.