Resumo em Inglês:

Abstract Temperate japonica rice plays a very important role in food security. In this study, a set of 191 temperate japonica accessions from 30 countries were planted in two sites in China, and 12 agronomic traits were measured. The results showed a wide range of variation for the traits measured. Most of the accessions are short; three accessions with large panicles and seven accessions with large grains were identified. Sixty-two quantitative trait loci (QTLs) were identified for 12 traits that were measured. Among them, twenty-one QTLs were identified in both experiments, and 41 QTLs were identified in only one site. Some known genes are located in the QTL regions identified in our study. SNP markers for grain size were identified and could be efficiently used for breeding selection. This study provided useful information for future gene validation and marker assisted selection for some important agronomic traits of temperate japonica rice.

Resumo em Inglês:

Abstract In order to assess the genotype by environment interaction (GE) and select genotypes to exploit narrow and broad adaptations, twenty-two spring oilseed rape genotypes were subjected to field surveys at five experimental sites in the 2015-16 and 2016-17 growing seasons. Plant materials were sown in the form of a randomized complete block design with three replicates. The additive main effects and multiplicative interaction (AMMI) model was used to determine the genotype, environment, and GE effects. The sum of squares (SS) for the first three interaction principal components was very close to the SS for the GE signal; therefore, AMMI3 was diagnosed as the most accurate model to optimize predictive accuracy. SAN48 had the highest broad adaptability. In total, the chances of increasing yield were 55.80% from broad adaptations, 26.73% from narrow adaptations with 4 mega-environments, and an additional 17.47% from narrow adaptations with 5 mega-environments.

Resumo em Inglês:

Abstract A large collection of coffee genetic resources is conserved in Costa Rica. In this study, microsatellite DNA fingerprinting of coffee through singleplex and multiplex PCR approaches coupled with capillary electrophoresis are described. To validate both methods, germplasm of Coffea spp. (Arabica and non-Arabica) and intraspecific F1 hybrids were analyzed using fourteen microsatellite markers. It was observed that through both PCR methods the fingerprinting profile of a subset of samples was identical. The genetic analyses revealed that non-Arabica coffee displayed greater genetic variation than Arabica coffee did. In addition, microsatellite analyses allowed the separation of C. arabica from other species using the principal coordinate analysis (PCoA) approach. The neighbor-joining tree clustering analysis revealed either a grouping of wild genotypes separated from cultivars of C. arabica, or a relation of intraspecific F1 hybrids with parental lines. The utility of our methodology for the characterization of F1 hybrids not previously analyzed through SSR (Simple Sequence Repeats) fingerprinting is demonstrated.

Resumo em Inglês:

Abstract Water deficit stress is the abiotic factor with the highest impact on crop yield. The objective of this study was to evaluate grain yield (GY), the anthesis-silking interval (ASI) and drought tolerance indices in maize hybrids. We evaluated GY and the ASI of 86 hybrids under two moisture levels (normal irrigation and water stress) for three consecutive years. The stress susceptibility index, water stress tolerance, drought resistance coefficient, drought resistance index, stress tolerance index and harmonic mean were evaluated. There were significant hybrid x environment interactions for GY and the ASI. Differences in the ASI among environments ranged from 0 to 5 days. The hybrids P3862, 1I873, 1I923, 1I862 and 1J1211 showed high GY, associated with the highest drought tolerance indices. The stress tolerance index and harmonic mean indices can be used to identify higher-yielding maize hybrids in environments with and without water restriction.

Resumo em Inglês:

Abstract Our aim in this study was to evaluate common bean progenies for water use efficiency (WUE) and verify if selection carried out under conditions without water limitation reflects the selection carried out under stress conditions. Eighty progenies from the BRSMG Talismã x G4280 cross and 80 from the BRSMG Talismã x G6492 cross were evaluated with high water availability (HWA) and low water availability (LWA) in two locations and two years. Genetic variance, heritability, accuracy, expected gain from selection, correlated response to selection, genetic correlation between HWA and LWA and between the two traits evaluated, and risk index in the recommendation (RI) were estimated. Some progenies had a RI close to zero, were tolerant in LWA, and were responsive in HWA. Progenies with high grain yield and WUE could be identified. The two conditions of evaluation were equally efficient for selection, as verified by estimates of expected gains from selection.

Resumo em Inglês:

Abstract The major hindrance to guava fruit (Psidium guajava L.) growing is the low availability of cultivars for use by Brazilian producers, who usually rely on few options of genotypes to implement the crop. In the present study, 11 full-sib families were evaluated in a randomized-block experimental design with three replicates, in order to more efficiently select superior genotypes. Genetic parameters were estimated and the best genotypes were selected based on genetic value by applying the REML/BLUP statistical procedure. Additionally, genetic divergence was estimated based on the mean Euclidian distance between the individuals selected via BLUP. Based on genetic divergence, the best genotypes were selected for use as parents in new crosses aiming at continuity of the guava breeding program. The mean values of the traits of selected individuals surpassed the mean values of their parents, confirming that the strategy of obtaining full-sib families is effective in generating considerable gains.

Resumo em Inglês:

Abstract This study aimed to investigate genetic parameters and selection strategies for sugarcane resistance to borer and determine the effects of selection for borer resistance on yield traits. The infestation index by borer (IIB) and yield traits were assessed over 3 years in 35 sugarcane clones planted in four locations in southeastern Brazil. There was no genotype × environment (year or location) interaction for borer resistance. Consequently, selection may be performed at only one location and year or by the mean of clones in several locations and/or years. The borer population affected the genotypic variance for borer resistance but when genotypic variance was significant, heritability was elevated and suitable genetic gain was achieved. Selection for borer resistance reduced the genetic gains for tons of cane per hectare, theoretical recoverable sugar, and tons of sugar per hectare; however, satisfactory selection gains for both borer resistance and yield were achieved using selection index.

Resumo em Inglês:

Abstract Paspalum notatum is an important forage native to Southern Brazil and one of the most promising fodder species in terms of productivity, quality, resistance and growth speed. The objective of this study was to evaluate the reproductive mode and fertility of hybrid progenies resulting from artificial crosses among artificially duplicated sexual plants, selected intraspecific hybrids of the UFRGS breeding program and apomictic ecotypes of the species. The resulting F1 progenies were represented by 24 plants with high pollen viability (varying from 82.15 to 99.67%) and 1.2:1 segregation for the sexual: apomictic reproduction mode, indicating predominantly sexual hybrids, due to distorted segregation. In the apomictic plants, most chromosomes paired as bivalents in diakinesis. Since the low presence of abnormalities observed in the meiotic chromosome pairing and the high pollen viability of the hybrids, all plants were confirmed as promising parents for future crosses.

Resumo em Inglês:

Abstract The aim of this study was to compare the Multiple Linear Regression and Artificial Neural Network models in prediction of grain yield of ten landrace varieties of lima bean and evaluate adaptability and stability through the Lin and Binns method for identification of the best performing variety. Trials were conducted in the municipalities of Teresina, PI, and São Domingos do Maranhão, MA, through measurement of 12 traits, except for grain yield in São Domingos do Maranhão. The parameters of Pearson and Spearman correlation, root mean square error, mean absolute error, and coefficient of determination were used to compare the models. The Artificial Neural Network proved to be more adequate for prediction of grain yield. Adaptability and stability analyses indicated that the environments are discriminant for selection of promising genotypes, and that the landrace variety Mulatinha can be recommended for planting in the municipalities.

Resumo em Inglês:

Abstract One of the reasons for the low market demand of blackberries in Brazil is the acid taste of the fresh fruit. The fruits of the newly released cultivar BRS Cainguá taste better and have a very attractive shape.

Resumo em Inglês:

Abstract The Embrapa peach breeding program provides a processing peach cultivar, 'BRS Jaspe'. Over the years, the yield of this cultivar was stable and its fruits can be harvested by mid-November and have a good size and taste. It may represent an alternative to cultivar Granada, with a similar maturation period.

Resumo em Inglês:

Abstract BRS 372 and BRS 416 are cotton cultivars with high lint yield and genetic resistance to the main cotton diseases in Brazil, particularly to Ramularia Leaf Spot. They have stable yields, good fiber quality and can contribute to a sustainable cotton disease management in tropical environments.

Resumo em Inglês:

Abstract SCS124 Sardo is a medium-maturing cultivar with an upright growth habit; intermediate lodging tolerance; moderate blast resistance; high grain yield potential; and long, thin grains with excellent cooking and sensory quality, especially for white milled rice. It is suitable for parboiling and recommended for all regions of the state of Santa Catarina, Brazil.

Resumo em Inglês:

Abstract ‘BRS 421’ and ‘BRS 423’ are high-oleic runner type peanut cultivars, adapted to the main peanut-producing areas in Brazil and partially resistant to spotted wilt. ‘BRS 421’ has a medium cycle and large seed size, while BRS ‘423’ has a short cycle and regular runner seed size.

Resumo em Inglês:

Abstract Bulk sampling and subsequent DNA fingerprinting are applied to obtain estimated allelic frequency data and unveil population structure for outbreeding species. We developed ‘Gametes Simulator’, a routine to simulate gametes from allelic frequencies of unlinked loci, which enables the analysis of population structure through Bayesian analysis. Based on the allelic frequencies in the populations, the software simulates the alleles per population in the right proportions and assigns one allele per marker to each gamete following Mendel’s laws that govern gametogenesis.

Resumo em Inglês:

Abstract Brazilian coffee cultivation was boosted over the last few decades by the mechanization of various field operations. Considering the influence of genetic factors on coffee harvesting efficiency, we aimed to evaluate the use of mechanized harvesting characteristics as a criterion to select progenies derived from ‘Icatu’ germplasm, previously evaluated for agronomic characteristics, resistance to rust and cercosporiosis. We also investigated genotypic and phenotypic correlations between semi-mechanized harvesting characteristics. Ten progenies of Coffea arabica L. were analyzed in two experimental farms during two consecutive harvests. Genetic parameters were evaluated to trace selection strategies. Four progenies that were suitable for mechanization were selected, supporting our hypothesis of the use of harvest characteristics as selection criteria.