Resumo em Inglês:

Abstract This study aimed to assess the influence of culture medium and cytokinin type on in vitro multiplication of an Eucalyptus grandis x E. urophylla hybrid clone via temporary immersion bioreactor (TIB®). JADS, modified MS at a (NO3ˉ):(NH +) ratio, and WPM were used as liquid media; and 6-benzilaminopurine (BAP), kinetin (KIN), and thidiazuron (TDZ) were the cytokinins used in the study. According to the results, explants under the influence of modified MS presented better results for all traits analyzed in this study. BAP was the most suitable plant growth regulator for axillary bud shoot proliferation. By the leaf histological analysis, most of the shoots grown in the presence of BAP either exhibited normal morphology or only a few hyperhydricity symptoms. All these results were obtained at 19 days after in vitro cultivation, a shorter period when compared with other works in the literature, showing the protocol efficiency in the multiplication of this hybrid clone using TIB®.

Resumo em Inglês:

Abstract The aim of this study was to estimate the repeatability of some phenotypic stability parameters: reliability index (I), regression coefficient (b 0 e b 1 ), ecovalence, and the mean of the absolute scores (MAS),and to check the implications of estimating stability parameters using a reduced number of environments. A data set comprising 25 common bean lines assessed in 36 environments was used. These environments comprise different locations, sowing seasons, and years. Different experimental groups, from three to 18 environments, were simulated. For each group, analysis of variance was performed and the stability parameters were estimated. The greater repeatability estimates were observed for the mean (b 0 ), followed by the I and b 1 . Ecovalence and MAS had the lowest values for the repeatability estimates, which is not desirable for breeding programs aiming at selection for high stability. The phenotypic stability parameter should not be estimated from fewer than 12 environments.

Resumo em Inglês:

Abstract The objectives of this study were to identify resistant and susceptible corn inbred lines based on their stability and adaptability for resistance to disease symptoms of gray leaf spot and northern leaf blight, suggest resistant inbred lines aimed at producing synthetics, and identify the sowing dates with higher occurrence of diseases to use these dates for identification of genetic resistance. We evaluated 41 corn inbred lines in randomized block designs with three replications and 11 sowing dates. Evaluations were performed 30 days after silking. Stability and adaptability analyses were performed by the regression method. The highest severities of disease occurred in sowing from June to September. On average, all the inbred lines were classified as resistant; however, considering adaptability and stability, five inbred lines were found suitable to produce dent synthetics resistant to both diseases. For flint synthetics resistant to both diseases, inbred lines IVF1-7, IVF1-10, 2F, 9F, and 10F are most suitable.

Resumo em Inglês:

Abstract The lack of genetic diversity is an obstacle for genetic improvement of upland cotton in China; thus, new technologies must be developed to produce more polymorphic molecular markers associated with agricultural traits of the existing resources for breeding. A highly efficient and economical technology of sequence-related amplified polymorphism (SRAP) molecular markers with an automated fragment analyzer ABI3500xl was developed, to detect genetic diversity in upland cotton. Using this new strategy, we easily screened for polymorphisms with 7,872 pairs of SRAP primers, and detected 504 polymorphic markers. Of all these, 165 were used for genetic diversity analysis in 128 upland cotton varieties collected nationwide in China. Our method combined a traditional molecular marker development technology with an economical and easy operation strategy for breeders.

Resumo em Inglês:

Abstract We evaluated domesticated Capsicum pepper species from Brazil using classical and molecular cytogenetic techniques, and describe here for the first time their immunostaining patterns using anti-H4K5ac and anti-H3S10ph antibodies. All accessions showed 2n = 24 chromosomes with metacentric and submetacentric morphologies. CMA3 patterns ranged from four terminal bands in most accessions to 18 variable CMA++/DAPI- and CMA+/DAPI0 bands. Anti-H4K5ac signals were detected in the decondensed terminal euchromatin of most chromosome arms, indicating gene-rich open chromatin regions. Anti-H3S10ph signals were restricted to pericentromeric regions and were associated with sister chromatid cohesions and/or the condensation of all mitotic chromosomes. These karyological analyses constitute valuable diagnostic tools for identifying cultivated peppers, will be important to Capsicum breeding programs and will provide additional cytogenetic features that can be used for the conservation of capsicum genetic resources.

Resumo em Inglês:

Abstract The objective of this work was to study the inheritance of soybean resistance to Soybean Steam Necrosis (SSN) and to map the resistance gene(s), using an F2 population from the cross between the soybean cultivars BRS 133 (resistant) and CD 206 (susceptible). A phenotypic evaluation was performed under controlled conditions, in a greenhouse. In a population of 114 F2 plants, 92 were resistant, and 22 were susceptible. The result is compatible with the inheritance of one dominant gene (χ2=1.98, P = 15.97%). Analysis of F1 and backcross populations confirmed the inheritance of one dominant gene. Bulk segregant analysis (BSA) was used as the mapping strategy. The resistance gene was mapped on chromosome 18 of the soybean genome, between markers Sat_308 and Satt303. This dominant gene is located on the same chromosome where the recessive SSN resistance gene rbc1 was mapped, at 8cM distance, and was named Rbc2.

Resumo em Inglês:

Abstract We report the in vitro induction of polyploids from two cassava cultivars by colchicine treatment. Shoot nodal segments, collected from in vitro cultivated plants of Porquinho and Vassourinha cultivars, were used as explants. Explants were treated in liquid media without and with colchicine (0.05, 0.10 or 0.15%), at 90 rpm, in the dark, for 48 or 96 h. Normal-like and putative-polyploid phenotypes were recovered from in vitro culture, for both cultivars. All plants from the putative-polyploid group were confirmed as tetraploids by flow cytometry and root tip chromosome counting, whereas no association was found between ploidy level and phenotype in normal-like plants. Mixoploids were also recovered from both cultivars. Vassourinha was more responsive to colchicine treatment than Porquinho. Tetraploid plants have fewer, but bigger, stomata guard cells than those in diploids. Colchicine at 0.10% for 96 hours induced a high number of tetraploids in both cultivars.

Resumo em Inglês:

Abstract The clustered regularly interspaced short palindromic repeat (CRISPR)/CRISPR-associated (Cas) technology has recently emerged as a powerful genomic editing tool with great potential for crop breeding. However, commonly used protocols for screening of CRISPR/Cas9-induced mutations are laborious, time-consuming, and costly. In the present study we examined the applicability of high resolution melting (HRM) analysis fast screening CRISPR/Cas9-induced mutations in T0 plants and subsequent genotyping of T1 populations. Comparative analysis demonstrated that HRM analysis could identify mutant T0 plants carrying various types of mutation, including single nucleotide substitutions and short insertion/deletions, with false positive/negative rates of 0-2.78%. Furthermore, T1 plants derived from single T0 plants could be correctly genotyped by HRM analysis using WT parents and T0 plants as controls. We hence recommend the adoption of HRM analysis in CRISPR/Cas9 mediated genetic studies and breeding in rice and other crop species.

Resumo em Inglês:

Abstract J. curcas (physic nut) is one of the most promising oilseeds for biofuel production and the knowledge about genetic parameter estimates is important for its breeding. Here, we evaluated 121 families, from 48 to 60 months of age, aiming genetic evaluation and selection. The trial was set up in an 11 x 11 lattice design, with three replications and 4-plant plot. The traits evaluated were fruit yield (FY), grain (GY) and oil yield (OY), fruit husk percentage (FH) and seed oil content (OC). Individual heritabilities were low (0.19 to 0.23), requiring accurate selection and improvement methods. Moderate repeatabilities were observed for FY (0.54), GY (0.52), OC (0.30) and OY (0.51), indicating that the families evaluated maintained relative superiority over the years. With selection of the 20 best individuals, the predicted genotypic gains (66%) were greater than the additive gains (56%), indicating greater possibilities of success from cultivation of clones.

Resumo em Inglês:

Abstract Fiber length is the main trait that needs to be improved in cotton. However, the presence of genotypes x environments interaction for this trait can hinder the recommendation of genotypes with greater length fibers. The aim of this study was to evaluate the adaptability and stability of the fibers length of cotton genotypes for recommendation to the Midwest and Northeast, using artificial neural networks (ANNs) and Eberhart and Russell method. Seven trials were carried out in the states of Ceará, Rio Grande do Norte, Goiás and Mato Grosso do Sul. Experimental design was a randomized block with four replications. Data were submitted to analysis of adaptability and stability through the Eberhart & Russell and ANNs methodologies. Based on these methods, the genotypes BRS Aroeira, CNPA CNPA 2009 42 and CNPA 2009 27 has better performance in unfavorable, general and favorable environment, respectively, for having fiber length above the overall mean of environments and high phenotypic stability.

Resumo em Inglês:

Abstract The objective of this work was to analyze the content and the chemical diversity of the essential oil (EO) of 22 Eplingiella fruticosa plants collected in Sergipe, Brazil. EOs were obtained from dry leaves by hydrodistillation and analyzed by GC/MS-FID. The mean EO contents ranged from 0.75 to 1.28%. The compounds found in greater amounts formed two clusters. The first cluster consisted of 15 plants and presented bicyclogermacrene (6.29-16.24%), spathulenol (7.59-15.23%), β-caryophyllene (5.77-12.97%), and caryophyllene oxide (5.00-11.90%) as major compounds. The second cluster consisted of seven plants and had 1,8-cineole (8.96-15.51%), α-pinene (5.46-13.77%), and camphor (4.08-11.40%) as major compounds. Results indicate chemical variability of the EO among E. fruticosa plants from the state of Sergipe. This information may assist in conservation strategies by providing data for investigation of biological activities of EO.

Resumo em Inglês:

Abstract Line A915.34.01.08 is a new source of resistance to Liriomyza sativae in melon. It was obtained by the genealogical method from a heterozygous plant with antibiosis type of resistance found within the accession CNPH 00-915. This line allows making introgression of this resistance in melon lines to develop commercial hybrids.

Resumo em Inglês:

Abstract Transgenic cotton cultivars BRS 430 B2RF and BRS 432 B2RF, medium and late season respectively, were developed by EMBRAPA in partnership with Bahia Foundation, aiming to create a high-yielding germplasm. The Bt toxins Cry1Ac and Cry2Ab target lepidopteran pests and the CP4-EPSPS gene confers tolerance to the herbicide glyphosate.

Resumo em Inglês:

Abstract A partnership program of Embrapa and BASF resulted in the development of a new irrigated rice cultivar adapted to the Clearfield® production system in Rio Grande do Sul. The cultivar is tolerant to the imidazolinone herbicide kifix®. In field trials in Rio Grande do Sul it produced a mean yield of 8394 kg ha-1.

Resumo em Inglês:

Abstract ‘SCS438 Zafira’ is a novel plum cultivar, adapted to southern Brazil. It produces high-quality fruits, very similar to ‘Fortune’, the standard mid-season cultivar. Its main advantage is the resistance to leaf scald. Apparently, the mechanism of resistance blocks the transmission of the bacteria by natural insect vectors (sharpshooters).

Resumo em Inglês:

Abstract ‘BRS Citrino’ is a highly productive canning peach that has a round to conic shape. The flesh has a sweet acid flavor with a slight bitterness, giving a good quality product when canned. It is adapted to southern Rio Grande do Sul, where the production of processed peaches is concentrated.

Resumo em Inglês:

Abstract IAC 125 RN was derived from a cross between the coffee cultivar Villa Sarchí and the Hibrido de Timor CIFC 832/2. The coffee trees are short and resistant to races 1 and 2 of the nematode Meloidogyne exigua and to all races of coffee rust, Hemileia vastatrix, present in Brazil. Brazil.

Resumo em Inglês:

Abstract In order to successfully achieve the final goal of genotype selection in plant breeding programs, many aspects must be considered and carefully thought regarding cost, time, and efficiency. Thus, we have developed the Be-Breeder application to perform main biometric and statistical analyses using mixed and multivariate models. Implemented using the Shiny R package, this is one the first online platforms proposed in this context. Be-Breeder is available at http://www.genetica.esalq.usp.br/alogamas/R.html.