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Abstract The objective of this work was to characterize chilling tolerance in rice mutant families of the M4 generation, at the seedling stage. Two experiments were carried out: chilling tolerance was evaluated in 43 mutant families, in the 'BRS Querência' original genotype, and in 19 commercial genotypes. In Experiment II, 8 mutant families from Experiment I, 'BRS Querência', and a mutant of the M5 generation were tested. In both experiments, seedlings were evaluated under two conditions: 10°C for seven days and 25°C for seven days. In Experiment I, the induced mutations in rice led to varied responses in chilling tolerance traits, with some M4 mutant families outperforming the original genotype. Experiment II highlighted the impact of mutations on chilling-tolerance, particularly in terms of leaf discoloration and plant recovery. Mutant families of the M4 generation differ from the original genotype 'BRS Querência' in chilling tolerance at the seedling stage. The mutant families M36, M54, and M56 and 'BRS Querência' show genetic similarity, indicating a lack of chilling tolerance during the seedling stage. The mutant families M17, M21, M22, and M26 are promising for rice breeding programs because they present chilling tolerance. The M30 mutant family exhibits the best performance for all analyzed traits, indicating chilling tolerance at the seedling stage.

The cultivation of the olive tree is of great economic importance worldwide. For the 2022-2023 harvest, were produced around 3,010,000 Mg of olive oil and 2,955,500 Mg of table olives of selected varieties, managing to establish itself in approximately 56 countries with different environments. In most of the cultivated areas only monovarietals were used, but mixtures of varieties have been recommended, which act as pollinators, avoiding reproduction problems. Furthermore, global warming also affects production efficiency and the quality of derived products. The olive grove underwent important changes due to genetic improvement. However, despite modern molecular tools, most of the work continues to be based on agronomic classical methods such as crossing and selection in progeny, delaying the development of new varieties. Models with high resolution climate projections are being used, allowing predicting the future evolution of the olive tree. Unfortunately, Brazil produces only 0.2% of its internal consumption and therefore has become the world's second largest importer after the United States to cover the growing demand. Based on this information, this review aims to discuss the adjustments in olive growing, which has been gaining more and more areas dedicated to its cultivation in Brazil.

ABSTRACT Rice (Oryza sativa) is among the most important crops worldwide; however, rice crops demand high water consumption. Future projections indicate reduced water availability and severe drought events, which may affect rice crops as the cereal is highly sensitive to drought stress. Thus, cultivars with lower water demand for irrigation or drought escape capacities are among the strategies to address this issue. This study aimed to assess five mutant rice genotypes in terms of growth cycle length, other agronomic interest traits, and drought response in the reproductive stage. The mutant genotypes evaluated showed a shortening of the growth cycle compared to the original cultivar, BRS Pampeira, representing a drought escape strategy. In addition, mutations did not negatively affect plant height and crop yield. However, similar to the original cultivar, mutants are not tolerant to water deficit in the reproductive stage. The genotypes evaluated have potential to be released as early cycle cultivars, which can reduce water demand during the harvest season while presenting a drought escape strategy.

Abstract The objective of this work was to determine the genetic correlations and the direct and indirect associations of agronomic traits and grain quality attributes with the percentage of whole grains in flood irrigated rice. The experiment was carried out in two environments, in a randomized complete block design with three replicates, using 23 irrigated rice genotypes. The evaluated traits were: percentage of whole grains, caryopsis length, caryopsis width, panicle length, panicle weight, 1,000 grain weight, days to flowering, percentage of chalky grains with white belly, total chalky area, total whiteness, vitreous whiteness, and defects in coloring. The percentage of grains with white belly and total chalky area were positively correlated, whereas the percentage of grains with white belly and vitreous whiteness were negatively correlated. The traits caryopsis width, percentage of chalky grains with white belly, panicle weight, and 1,000 grain weight showed indirect effects on whole-grain yield response according to total chalky area and total whiteness. Total chalky area and total whiteness are the factors that most negatively influence the percentage of whole grains according to the genotypic correlations and direct effects.

Abstract The objective of this work was to map the chromosomal regions responsible for iron accumulation in rice grains, in Southern Brazil. Eighty-one rice accessions were genotyped and phenotyped for Fe accumulation. Single nucleotide polymorphisms were mapped in the whole grain on chromosomes 1, 5, 6, and 10, from which 13 candidate genes were identified. Some of the genes, such as O s10g040680 0, seem to have a relationship with Fe homeostasis, while others are related to other metabolic processes or have an unknown function.

Abstract Effective strategies for disease control are crucial for sustaining world food production and ensuring food security for the population. Wheat blast, a disease caused by the pathogen Magnaporthe oryzae pathotype Triticum, has been a concern for cereal producers and researchers due to its aggressiveness and rapid expansion. To solve this problem, the development of resistant varieties with durable resistance is an effective, economical and sustainable way to control the disease. Conventional breeding can be aided by several molecular tools to facilitate the mining of many sources of resistance, such as R genes and QTLs. The identification of new sources of resistance, whether in the wheat crop or in other cereals are an opportunity for efficient wheat breeding through the application of different techniques. Since this disease is still poorly studied in wheat, knowledge of the rice Magnaporthe pathotype may be adapted to control wheat blast. Thus, genetic mapping, molecular markers, transgenic approaches, and genomic editing are valuable technologies to fight wheat blast. This review aimed to compile the biotechnological alternatives available to accelerate the development of improved cultivars for resistance to wheat blast.

The genus Vitis belongs to the Vitaceae family and is divided into two subgenera: Muscadinia and Vitis, the main difference between these subgenera being the number of chromosomes. There are many hypotheses about the origin of the genus, which have been formed with archaeological studies and lately with molecular analyses. Even though there is no consensus on the place of origin, these studies have shown that grapes have been used by man since ancient times, starting later on its domestication. Most studies point to the Near East and Greece as the beginning of domestication, current research suggests it took place in parallel in different sites, but in all cases Vitis vinifera (L.) subsp. sylvestris [Vitis vinifera (L.) subsp. sylvestris (Gmelin) Hagi] seems to be the species chosen by our ancestors to give rise to the now known Vitis vinifera (L.) subsp. vinifera [=sativa (Hegi)= caucasica (Vavilov)]. Its evolution and expansion into other territories followed the formation of new empires and their expansion, and this is where the historical importance of this crop lies. In this process, plants with hermaphrodite flowers were preferentially selected, with firmer, sweeter, larger fruits of different colors, thus favoring the selection of genes associated with these traits, also resulting in a change in seed morphology. Currently, genetic improvement programs have made use of wild species for the introgression of disease resistance genes and tolerance to diverse soil and climate environments. In addition, the mapping of genes of interest, both linked to agronomic and fruit quality traits, has allowed the use of molecular markers for assisted selection. Information on the domestication process and genetic resources help to understand the gene pool available for the development of cultivars that respond to producer and consumer requirements.

In Rio Grande do Sul, the main rice producer State in Brazil, low temperatures can occur during germination and seedling establishment, and in some cases, during the reproductive stage. When low temperatures occur in the early developmental stages cause delay in germination, resulting in a non-homogeneous growing. In reproductive stage, low temperatures cause spikelet sterility, directly interfering with plant yield. Researchers have shown that some phenolic compounds such as proanthocyanidins and anthocyanin are associated with low temperature tolerance in plants due to their antioxidant capacity. The red and black color in the seeds of some rice genotypes is conferred by the phenolic compounds proanthocyanidins and anthocyanin, respectively. Therefore, tis study aimed to verify whether rice genotypes with red or black seeds are more tolerant to low temperatures during germination. In this study, five rice genotypes were tested, two present seeds without pigmentation and with contrasting response to low temperature tolerance (BRS Bojuru - tolerant and BRS Pampeira - sensitive), two genotypes with red seeds (BRS 902, SCS 119 Rubi) and one black seed genotype (SCS 120 Ônix). As expected, the genotypes with pigmented seeds had a greater total phenolic compounds content. However, under low temperature conditions, the genotypes with pigmented seed showed a similar response to the sensitive genotype. Therefore, the presence of proanthocyanidins and anthocyanin in the seed of the studied genotypes does not provide tolerance to low temperatures during germination.

Rice production (Oryza sativa L.) is among the most economically important activities in the world. However, soil and salinity coming from irrigation water reduce rice yield. Therefore, the identification and/or development of salt-tolerant rice genotypes is a strategy to minimize this problem. The development of new genotypes depends on the presence of genetic diversity, and understanding the heritability of a desired trait can help in the selection process. Thus, this study aimed to identify superior genotypes, analyze the genetic diversity and estimate the heritability for salinity tolerance at the seedling stage in rice genotypes used in Brazil. For this, seedlings of 69 genotypes were kept in hydroponic solution with 40 mM NaCl (4 dSm-1) for seven days. Shoot length, root length, shoot dry weight, and root dry weight) were evaluated and the results were converted into relative performance. Tolerant and moderately salt-tolerant genotypes were identified at the seedling stage, which can be used in breeding programs and can be cultivated in high salinity areas. Principal component analysis showed the presence of genetic diversity for salinity response. Finally, it was shown that most of the observed variation is of genetic origin, which can make the breeding process less difficult.

The olive crop has a large diversity in cultivars around the world, whose identification have been based on leaf, stem or fruit traits. However, these traits may be influenced by the environment, which has led to the misidentification of cultivars. The variability of the pistil and pollen structure under electron scanning and light microscopy were studied using the cultivars 'Arbequina', 'Arbosana', 'Frantoio', 'Koroneiki', 'Manzanilla de Sevilla' and 'Picual', cultivated in Southern Brazil. The aim was to find unique patterns for their identification. This type of study has not been carried out in the conditions of Southern Brazil, where the identification of commercial cultivars sometimes is complex and confusing. There were significant differences in the variables, showing uniformity within each cultivar in different locations. The principal component analysis indicated a separation of cultivars according to similarities or micromorphological differences in the pollen wall, area of the lumen and the structural elements of the tectum. For the analysis of the pistil, the separation was even clearer, each cultivar individually forming a cluster, using as characters the length of the style in contrast to the length, width and area of the stigma. This evidenced little variation among individuals within the same cultivar. The information provided can contribute to the individual identification of very close olive tree cultivars in the conditions of Southern Brazil.

Abstract The objective of this work was to analyze components of variances and heritabilities, estimate selection gain, and evaluate the different selection pressures for physical quality attributes of grains of families of segregating generations of irrigated rice (Oryza sativa), through the REML/BLUP methodology. The experiment was conducted in the state of Rio Grande do Sul, Brazil, where selections were made in the F3, F4, and F5 segregating generations, in the 2015/2016, 2016/2017, and 2017/2018 crop seasons, in eight segregating populations (families) from different crosses. Intrinsic physical quality attributes, genetic parameters, and response to selection were evaluated using different selection pressures. The obtained estimates showed genetic gains for the characters related to grain quality, mainly for total chalky area, vitreous whiteness, total whiteness, ratio between vitreous whiteness and total whiteness, and percentage of whole grains and broken grains, in selections in early generations. The used families show satisfactory results, being superior to the control cultivars. For most characters, the estimates of broad-sense heritability are considered intermediate, together with the other parameters, showing the possibility of genetic selection for grain quality attributes. The response to selection with a pressure of 10% is very promising for rice grain quality attributes.

Abstract Objectives This study was conducted to establish a method for early, quick and cheap screening of iron excess tolerance in rice (Oryza sativa L.) cultivars. Results Based on the experiments, iron excess leads to reduction in shoot length (SL) and this can be a useful characteristic for adequate screening of tolerant genotypes. The sensitive genotypes Nipponbare and BR-IRGA 409 indicated higher accumulation of iron in their tissues while BRS-Agrisul and Epagri 108 also accumulated iron, but at lower concentrations. BR-IRGA 410 displayed an intermediate phenotype regarding iron accumulation. No changes in shoot Cu content can be observed when comparing treatments. On the other hand, an increase was seen for Zn and Mn when shoots are subjected to Fe2+ excess. Fe stress at a lower concentration than 7 mM increased Zn but decreased Mn contents in shoots of BR-IRGA 409. Strong positive correlations were found here for Fe × Zn (0.93); Fe × Mn (0.97) and Zn × Mn (0.92), probably due to the Fe-induced activation of bivalent cation transporters. Results show that genotypes scored as sensitive present higher concentration of Fe in shoots and this is an efficient method to characterize rice cultivars regarding iron response.

In the present work, we study the genetic control of reproductive traits under different heat stress conditions in two populations of inbred lines derived from crosses between two S. pimpinellifolium accessions and two tomato cultivars (E9×L5 and E6203×LA1589). The temperature increase affected the reproductive traits, especially at extremely high temperatures, where only a few lines were able to set fruits. Even though a relative modest number of QTLs was identified, two clusters of QTLs involved in the responses of reproductive traits to heat stress were detected in both populations on chromosomes 1 and 2. Interestingly, several epistatic interactions were detected in the E9×L5 population, which were classified into three classes based on the allelic interaction: dominant (one locus suppressed the allelic effects of a second locus), co-adaptive (the double-homozygous alleles from the same parent alleles showed a higher phenotypic value than the combination of homozygous alleles from alternative parents) and transgressive (the combination of double-homozygous alleles from different parents showed better performance than double-homozygous alleles from the same parents). These results reinforce the important role of non-additive genetic variance in the response to heat stress and the potential of the new allelic combinations that arise after wide crosses.

Abstract Background SUMOylation is an essential eukaryotic post-translation modification that, in plants, regulates numerous cellular processes, ranging from seed development to stress response. Using rice as a model crop plant, we searched for potential regulatory points that may influence the activity of the rice SUMOylation machinery genes. Results We analyzed the presence of putative cis-acting regulatory elements (CREs) within the promoter regions of the rice SUMOylation machinery genes and found CREs related to different cellular processes, including hormone signaling. We confirmed that the transcript levels of genes involved in target-SUMOylation, containing ABA- and GA-related CREs, are responsive to treatments with these hormones. Transcriptional analysis in Nipponbare (spp. japonica) and LC-93-4 (spp. indica), showed that the transcript levels of all studied genes are maintained in the two subspecies, under normal growth. OsSUMO3 is an exceptional case since it is expressed at low levels or is not detectable at all in LC-93-4 roots and shoots, respectively. We revealed post-transcriptional regulation by alternative splicing (AS) for all genes studied, except for SUMO coding genes, OsSIZ2, OsOTS3, and OsELS2. Some AS forms have the potential to alter protein domains and catalytic centers. We also performed the molecular and phenotypic characterization of T-DNA insertion lines of some of the genes under study. Knockouts of OsFUG1 and OsELS1 showed increased SUMOylation levels and non-overlapping phenotypes. The fug1 line showed a dwarf phenotype, and significant defects in fertility, seed weight, and panicle architecture, while the els1 line showed early flowering and decreased plant height. We suggest that OsELS1 is an ortholog of AtEsd4, which was also supported by our phylogenetic analysis. Conclusions Overall, we provide a comprehensive analysis of the rice SUMOylation machinery and discuss possible effects of the regulation of these genes at the transcriptional and post-transcriptional level. We also contribute to the characterization of two rice SUMO proteases, OsELS1 and OsFUG1.

Abstract: The objective of this work was to evaluate the consistency of the methods of Annicchiarico, Lin & Binns, Wricke, and factor analysis in identifying eucalyptus clones with stability, adaptability, and high productive potential. Eight-four clones, with three years of age, from the genetic breeding program of the company CMPC Celulose Riograndense were used. Three field experiments were carried out in a randomized complete block design, in an 84x3 factorial arragement, with 20 replicates of one plant per plot. The clones were evaluated as to diameter at breast height, plant height, and volume of wood. The methods of Annicchiarico and Lin & Binns are highly correlated with each other, and their use together with the method of Wricke is a sound strategy for the evaluation of eucalyptus clones. The factor analysis identified broadly adaptable clones, and some of them were the same ones identified by the methods of Annicchiarico and Lin & Binns. The use of the mean classification of the clones, along with the factor analysis, is efficient to identify the most adapted, stable, and productive ones among a high number of genotypes.

Abstract: The objective of this work was to compare uni- and multivariate biometric methods to evaluate the adaptability and stability of an important group of white oat (Avena sativa) cultivars grown in Southern Brazil. The used experimental design was a randomized complete block, in a factorial arrangement of 12 environments x 7 cultivars, with three replicates. The analysis of variance and the methods of Eberhart & Russel, Annicchiarico, and the harmonic mean of the relative performance of predicted genetic values (MHPRVG) were assessed. In the general comparison of the methods, the 'UPFA Gaudéria' and 'URS Guapa' genotypes were more stable regarding grain yield. The 'UPFA Gaudéria' and 'URS-21' genotypes stood out for hectoliter weight, presenting the best performances by the methods of Annicchiarico and the MHPRVG. For thousand-grain weight, all methods showed similar results, indicating that the 'UPFA Gaudéria' genotype presented the best results. The 'URS Guapa' genotype was superior when using the methods of Eberhart & Russel, Annicchiarico, and the MHPRVG. The uni- and multivariate methods evaluated are suitable to estimate with high confidence the adaptability and stability of cultivars for each targeted grain production, yield, and quality.

Background: Fusarium Head Blight (FHB) is a worldwide devastating disease of bread wheat (Triticum aestivum L.). Genetic resistance is the most effective way to control FHB and many QTL related to this trait have been mapped on the wheat genetic map. This information, however, must be refined to be more efficiently used in breeding programs and for the advance of the basic research. The objective of the present study was to in-depth analyze the QTLome of FHB resistance in bread wheat, further integrating genetic, genomic, and transcriptomic data, aiming to find candidate genes.Methods: An exhaustive bibliographic review on 76 scientific papers was carried out collecting information about QTL related to FHB resistance mapped on bread wheat. A dense genetic consensus map with 572,862 loci was generated for QTL projection. Meta-analysis could be performed on 323 QTL. Candidate gene mining was carried out within the most refined loci, containing genes that were cross-validated with publicly available transcriptional expression data of wheat under Fusarium infection. Most highlighted genes were investigated for protein evidence.Results: A total of 556 QTL were found in the literature, distributed on all sub-genomes and chromosomes of wheat. Meta-analysis generated 65 meta-QTL, and this refinement allows one to find markers more tightly linked to these regions. Candidate gene mining within the most refined meta-QTL, meta-QTL 1/chr. 3B, harvested 324 genes and transcriptional data cross-validated 10 of these genes, as responsive to FHB. One is of these genes encodes a Glycosiltransferase and the other encodes for a Cytochrome P450, and these such proteins have already been verified as being responsible for FHB resistance, but the remaining eight genes still have to be further studied, as promising loci for breeding.Conclusions: The QTLome of FHB resistance in wheat was successfully assembled and a refinement in terms of number and length of loci was obtained. The integration of the QTLome with genomic and transcriptomic data has allowed for the discovery of promising candidate genes for use in breeding programs.

O tegumento apresenta uma função importante quanto à resistência das sementes e a sua deterioração. Sendo assim, torna-se necessário entender os mecanismos de genes responsáveis por caracteres que possam auxiliar no desenvolvimento de variedades com melhor qualidade. Nesse sentido, a análise da expressão do gene fla 14 que codifica para a proteína Arabinogalactana que esta relacionada diretamente com a síntese da parede celular no tegumento da semente de soja pode contribuir para o avanço dos estudos. Sendo assim, o objetivo do trabalho foi validar primers e analisar o perfil da expressão do gene fla 14 em quatro genótipos de soja, dois desses com tegumento preto (TP e IAC 222) e maior conteúdo de lignina, e outros dois com tegumento amarelo (CD 202 e Potência) e menor conteúdo de lignina. O tecido vegetal (tegumento) foi coletado aos 50 dias após a antese. Para a análise da expressão gênica dos genótipos, utilizou-se a técnica de qRT-PCR, onde foram testadas quatro combinações de primers construídos a partir de modelos de sequência de ESTs da soja. Os resultados da validação demostraram a eficiência dos primers FLA 14 p1 e FLA 14 p2 para serem utilizados em estudos de expressão gênica. Em relação ao gene fla 14, pode-se observar que o perfil de expressão deste gene é quantitativamente superior nos genótipos de soja com tegumento preto e conteúdo superior de lignina quando relacionado com os genótipos com tegumento amarelo e menor teor de lignina.

Looking at the new demands of the global agricultural scenario, the search for more productive, efficient and stress adapted genotypes has attracted attention of plant breeders regarding plants with improved physiological characteristics. Therefore, the stay-green trait has taken proeminence as an important strategy to overcome the current yield plateaus allied with yield adaptability and stability. This review has aimed to bring light the main aspects of the stay-green character, showing their employment potential of plant breeding.

Abstract:The objective of this work was to characterize the performance of elite wheat genotypes from different Brazilian breeding programs for traits associated with grain yield and preharvest sprouting. The study was conducted in 2010 and 2011 in the municipality of Capão do Leão, in the state of Rio Grande do Sul, Brazil, in a randomized complete block design with three replicates. Thirty-three wheat genotypes were evaluated for traits related to preharvest sprouting and grain yield. The estimate of genetic distance was used to predict potential combinations for selection of plants with high grain yield and tolerance to preharvest sprouting. The combined analysis of sprouted grains and falling number shows that the TBIO Alvorada, TBIO Mestre, Frontana, Fundacep Raízes, Fundacep Cristalino, and BRS Guamirim genotypes are tolerant to preharvest sprouting. Combinations of TBIO Alvorada and TBIO Mestre with Fundacep Cristalino show high potential for recovering superior genotypes for high grain yield and tolerance to preharvest sprouting.

O objetivo deste trabalho foi determinar o desempenho per se e os parâmetros genéticos de caracteres de interesse, em linhagens de trigo que expressam ou não o caráter "stay‑green". O experimento foi conduzido em 2003, 2004 e 2005, em delineamento experimental de blocos ao acaso, com três repetições. Foram avaliadas 32 linhagens irmãs de trigo, 15 com e 17 sem o caráter "stay‑green". As linhagens portadoras desse caráter apresentaram maior produtividade de grãos, maior número de grãos por espiga e menor massa de mil grãos. Além disso, as herdabilidades da produtividade e da massa de grãos foram maiores nessas linhagens, o que revelou menor influência de variações ambientais sobre a expressão desses caracteres. O caráter "stay‑green" contribui para o aumento da produtividade e da estabilidade produtiva do trigo.The objective of this work was to determine the per se performance and the genetic parameters of traits of interest in wheat inbred lines expressing or not the "stay‑green" character. The experiment was carried out in 2003, 2004, and 2005 in a randomized complete block design with three replicates. Thirty‑two sister‑lines of wheat, 15 with and 17 without the stay‑green character, were evaluated. The lines carrying this character showed higher grain yield, higher average number of kernels per ear, and lower weight of a thousand grains. Moreover, grain yield and grain mass heritabilities were higher in these lines, which reveled lower influence of environmental variation on the expression of these characters. The "stay‑green" character contributes to increase productivity and productive stability of wheat.

The white oat cultivar FAEM Chiarasul was developed from a cross between UFRGS 17 and UFGS 10/ Coronado2/Cortez3/Pendek/ME 1563. It is characterized by reduced plant height, and high yield, grain quality and grain-processing quality

The palm tree family (Arecaceae) is constituted by approximately 3000 species mainly distributed in the tropics and subtropics. As a source of a variety of products they contribute to the world and local economies, and also to peoples lifestyles. Historically their use has been based on wild populations, but also on local domestication. Very few species are subject of plant breeding programs and are cultivated in the world. This is the case of the African oil palm (Elaeis guineensis), in which investment and development consortiums invest high sums. Another kind of crop is the date palm (Phoenix dactylifera), which was domesticated thousand of years ago and whose success is based in the export of a fine product with worldwide recognition. In this case the production is based on traditional varieties and has very incipient breeding programs. A third group of palms includes those species from which products are obtained and manufactured for local development. The objective of this literature review is to contribute in the analysis of opportunities and weaknesses to investing in domestication and plant breeding programs in those palm trees with a recognized productive value.A família das palmeiras (Arecaceae) é constituída por aproximadamente 3000 espécies, distribuídas principalmente nos trópicos e subtrópicos. Como fonte de uma variedade de produtos, contribuem para a economia mundial e local, e também para o modo de vida de várias pessoas. Historicamente, seu uso tem sido baseado em populações silvestres, mas também em domesticações locais. Muito poucas espécies estão submetidas a programas de melhoramento genético e são cultivadas a nível mundial. Este é o caso da palmeira de dendê (Elaeis guineensis), na qual consórcios de investimento e desenvolvimento investem altas quantias de dinheiro. Outro tipo de palmeira cultivada é a tamareira (Phoenix dactylifera), a qual foi domesticada milhares de anos atrás e cujo sucesso está baseado na exportação de produtos com reconhecimento mundial. Nesse caso, a produção está baseada em variedades tradicionais e os programas de melhoramento ainda são incipientes. Um terceiro grupo de palmeiras inclui aquelas espécies cujos produtos são obtidos e manufaturados para o desenvolvimento local. O objetivo desta revisão bibliográfica é contribuir para a análise de oportunidades e fragilidades no investimento em domesticação e programas de melhoramento das palmeiras com valor produtivo reconhecido.

The white oat cultivar FAEM Carlasul was developed at the Plant Genomics and Breeding Center, Faculty of Agronomy Eliseu Maciel, Federal University of Pelotas, as a result of the cross between UFRGS 10 and 90SAT-28 (Coronado2/Cortez3/Pendek/ME 1563). It is characterized by high yield and grain quality.

Solos do tipo hidromórfico apresentam uma reduzida capacidade de drenagem, sendo utilizados principalmente para cultivo de arroz irrigado. Esta condição favorece o desenvolvimento de microrganismos anaeróbios que produzem substâncias fitotóxicas. O objetivo do trabalho foi avaliar a resposta de 25 genótipos de arroz ao ácido butírico, um composto produzido em solos de deficiente drenagem e alto teor de matéria orgânica. O trabalho foi executado em sistema de hidroponia com 4 doses do ácido e o delineamento utilizado foi blocos casualizados com 3 repetições em um esquema fatorial. As variáveis mensuradas foram comprimento de raízes (CR) e de parte aérea (CPA), número de raízes (NR) e matéria seca de raízes (MSR) e parte aérea (MSPA). Foram procedidas análise de variância, desempenho relativo e ajuste de regressões. Os efeitos para genótipos e doses de ácido butírico foram todos significativos. Apenas os efeitos de interação entre doses x genótipos para as variáveis CR e MSR revelaram significância. A variável CR foi a mais afetada pelo ácido e as regressões estabelecidas para essa variável revelaram 9 genótipos tolerantes e 16 sensíveis ao efeito fitototoxico do ácido butírico. Genótipos desenvolvidos para sistema de irrigação por inundação se mostraram mais tolerantes ao ácido.Hydromorphic soils have low drainage capacity and are used mainly for growing irrigated rice.. This condition favors the development of anaerobic microorganisms that produce phytotoxic substances. The objective of this work was to evaluate the response of 25 rice genotypes to butyric acid, a phytotoxic compound produced in low-drainage soils with high organic matter content. This work was performed by hydroponics with four acid doses as treatments using a random block design with three replications. The variables measured were root (CR) and shoot (CPA) length, number of roots (NR) and root (MSR) and shoot (MSPA) dry matter. Analysis of variance, relative performance and regression fitting were performed. Significance for genotype and dose was found for all variables. Significance for the interaction (genotype vs. dose) was found only for CR and MSR. The variable CR was the most influenced by the acid and the regression established for these variables revealed nine tolerant and 16 sensitive genotypes. Genotypes developed for irrigated systems were more tolerant.

Tandem repeats (microsatellites or SSRs) are molecular markers with great potential for plant genetic studies. Modern strategies include the transfer of these markers among widely studied and orphan species. In silico analyses allow for studying distribution patterns of microsatellites and predicting which motifs would be more amenable to interspecies transfer. Transcribed sequences (Unigene) from ten species of three plant families were surveyed for the occurrence of micro and minisatellites. Transcripts from different species displayed different rates of tandem repeat occurrence, ranging from 1.47% to 11.28%. Both similar and different patterns were found within and among plant families. The results also indicate a lack of association between genome size and tandem repeat fractions in expressed regions. The conservation of motifs among species and its implication on genome evolution and dynamics are discussed.

O objetivo do trabalho foi avaliar a germinação de 12 genótipos de arroz submetidos ao estresse por ácido acético, composto fitotóxico produzido em solos com drenagem deficiente e alto teor de matéria orgânica. Foram realizados os testes de primeira contagem da germinação (PCG) e germinação (G) dos genótipos submetidos às concentrações de 0mM, 4mM, 8mM e 12mM de ácido acético. As sementes de cada genótipo foram colocadas em papel germitest, os quais foram embebidos com as soluções-tratamento e acondicionados em sacos individuais. A germinação foi executada em câmara a 25°C e as contagens realizadas aos sete (PCG) e aos 14 dias (G). O delineamento experimental utilizado foi fatorial inteiramente casualizado, com quatro repetições de 50 sementes por genótipo. As regressões estabelecidas para as variáveis revelaram três genótipos com estabilidade de germinação frente ao estresse por ácido acético.The objective of this research was to evaluate the germination of 12 rice genotypes under acetic acid stress, a phytotoxic compound produced in low drainage soils with high organic matter content. The tests were conducted with the first count of germination (PCG) and germination (G) of the genotypes subjected to 0mM, 4mM, 8mM and 12mM acetic acid concentrations. The seed of each genotype was placed in germitest paper that was embedded with treatment solutions and packaged in individual bags. The germination was performed at 25°C and the counts were carried out at 7 (PCG) and 14 days (G). A factorial random block design was performed with four replications of 50 seeds per genotype. The regressions set for the variables showed three genotypes with germination stability under acetic acid stress.

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.

Abstract 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.

ABSTRACT Improvement of quality-related traits of grains is a constant concern in white oat breeding programs, which challenges breeders to understand their dynamics. The performance of different genetic combinations must be thoroughly evaluated to make high nutritional quality cultivars available. This study aimed to estimate the heterosis on F1 and F2 generations, vigor loss, due to inbreeding, and correlation between the grain chemical components to understand the dynamics of these traits, considering two segregating oat progenies. The populations Albasul × UPF 15 (population 1) and IAC 7 × UFRGS 19 (population 2) were developed. Both populations showed transgressive segregant individuals. The combination Albasul × UPF 15 provided significant heterosis for traits β-glucan total and soluble fiber contents, while the population obtained by crossing IAC 7 × UFRGS 19 generated significant gain by heterosis for total fiber, insoluble fibers and non-structural carbohydrate contents. Considering the F2 average for each population, one can observe that population 1 presents higher β-glucan and lipid contents than population 2. On the other hand, population 2 has higher protein content than population 1. In both populations, the non-structural carbohydrate content is strongly and negatively correlated whith protein, total and insoluble fibers. Correlations between total fibers and lipids and between total fibers and insoluble fibers were both positive and high in both populations.

Abstract: The objective of this work was to evaluate the performance of intervarietal corn (Zea mays) hybrids with topcross crosses between landrace populations, and to confirm whether genetic dissimilarity between populations is correlated with the heterosis of the intervarietal hybrids in the field. Nine topcross hybrids were evaluated with their tester 'BRS Planalto', and the following landrace populations were used as parents: Argentino Branco, Dente de Ouro, Amarelão, Criolão, Caiano Rajado, Branco Oito Carreiras, Branco Roxo Índio, Cateto Branco, and Argentino Amarelo. The tester 'BRS Planalto' and the topcross hybrids Branco Oito Carreiras x 'BRS Planalto' and Criolão x 'BRS Planalto' showed higher per se potential for grain yield. The topcross hybrid Branco Oito Carreiras x 'BRS Planalto' showed a better performance for number of grains per row, grain weight, and ear diameter, whereas Criolão x 'BRS Planalto' displayed a better performance for the number of grains per row and ear length. Greater estimates of genetic distance did not necessarily result in greater heterosis values and were exclusively correlated with grain ear length. Therefore, it is not possible to predict the effects of high heterosis on grain yield, based on the genetic distance between the populations involved in the crosses.

ABSTRACT: The stay-green character has been related to greater stress tolerance and yield through longer activity of the photosynthetic apparatus. Association of this character with grain yield may be linked to a network of features other than the grain mass. This study aimed to shed light on the actual contribution of stay-green character in Brazilian wheats and the associations between grain yield components in different environmental conditions. The experiment was conducted in a randomized block design with three replications in the years 2003, 2004 and 2005. Sibling lines with and without the stay-green character were evaluated analyzing the phenotypic correlation and path analysis separately by year and maturity group. Under favorable growing conditions, the contribution of stay-green character in wheat is obtained by the increased ear fertility and number of grains. In a more restrictive scenario, it favors an increase in grain mass by longer filling time at the end of the cycle.