Resumo em Inglês:

Abstract According to literature, the apple cultivar SCS425 Luiza is a hybrid of Imperatriz♀ and Cripps Pink♂; however, molecular analysis of gametophytic self-incompatibility alleles showed the presence of an unexpected allele in SCS425 Luiza. This raised doubts about the fidelity of the pedigree. Thus, this study aimed to investigate the real genealogy of the SCS425 Luiza cultivar via fingerprint analysis. A total of 19 pairs of SSR primers covering 12 of the 17 chromosomes were used. ‘Imperatriz’ was tested as the female parent, and either ‘Cripps Pink’ or ‘Baronesa’ was tested as the presumed male parents. The results excluded ‘Cripps Pink’ as the male parent because most of the markers showed alleles of exclusion with Likelihood ratio (LR) value equal to zero. In contrast, when Baronesa was tested as the male parent, all alleles followed the expected segregation with very high LR values (>10.000). Therefore, it is concluded that the correct genealogy of the SCS425 Luiza cultivar is Imperatriz♀ and Baronesa♂.

Resumo em Inglês:

Abstract Image analysis is a straightforward and non-destructive technique used to identify haploids/diploids in maize. This study was carried out to characterize haploid/diploid maize kernels based on color space data and to compare the success of classification models developed using different machine learning techniques in maize. In this study, haploid (n=390) and diploid (n=495) kernels obtained by crossing five different donors with a Navajo inducer were used. Kernel images were collected using a standard desktop scanner. After extracting the RGB color space data, it was converted to hue-saturation-value (HSV) and Lab color spaces. Seven combinations of color space datasets were used as predictor variables. Support vector machines (SVM-C), random forest (RF), classification and regression tree (CART) methods were used to develop ML models. The classification success of the models was found between 0.74 and 0.86. The Support Vector Machines model (Accuracy = 0.86) created with RGB+Lab input data was the best.

Resumo em Inglês:

Abstract This study aimed to apply selection indexes in situations in which F2 populations and their parents are evaluated simultaneously in field trials to predict population genotypic values and selecting the best populations. Fifteen F2 soybean populations were evaluated for number of days to flowering and to maturity and grain yield. The data was analyzed using restricted maximum likelihood/best linear unbiased prediction (REML/BLUP) to obtain genotypic effects, variance components and accuracies. Four selection methods were compared: genotypic values of the F2 populations (gF2), combined index with the mean genotypic value of parents and F2 population (Ia) and two indexes that add (to gF2 and to Ia) and consider genetic variability within populations (Ib and Ic). The index Ia presented a result similar to that obtained with the gF2 selection method. Selection indexes (Ib and Ic) based on several sources of information were more efficient than selection based on gF2 values only.

Resumo em Inglês:

Abstract Spatial and non-spatial analyses were conducted to estimate genetic parameters for the traits leaf mass weight (LMW), crown height (CH), crown diameter (CD), and crown volume (CV) for ages between 21 and 27 in 10 half-sib progeny trials of Ilex paraguariensis St. Hill. The spatial model gave a better fit than the base model in 87.2% of the analysed dataset, with reductions in residual and plot variances. The narrow-sense heritability estimates ranged from low to moderate for LMW trait (0.01 to 0.43) and from low to high for crown traits (0.08 to 0.74). The additive genetic coefficient of variation for the LMW trait was over 12.4%, while for CH and CD it was below 10%. Generally, the additive genetic correlations ( r^a ) between the LMW evaluations and between LMW and crown traits were greater than 0.70.

Resumo em Inglês:

Abstract Traditionally, the quantification of anthocyanin content requires destructive sampling followed by chemical analysis with elaborate process. The aim of this study was to use non-destructive methods for prediction of anthocyanin by using color values from handheld colorimeter. Five hundred and fifty-eight yardlong bean samples that have pale green to dark purple pod color were used for color measurement and anthocyanin analysis. The partial least square regression (PLSR) was used to correlate spectral data with anthocyanin content. The PLSR model could predict anthocyanin content with correlation coefficient of 0.900 and standard error of prediction of 1.994 A/gFw. The results indicated that colorimeter readings can be correlated with anthocyanin content in yardlong bean and could be used as an alternative to chemical analysis. This method is reliable, rapid and inexpensive and can be used to screen a large number of yardlong bean accessions or populations under high anthocyanin breeding program.

Resumo em Inglês:

Abstract The pedigree analysis from genealogical data can estimate the inbreeding from identity-by-descent, being a powerful tool for germplasm characterization. The aim of this study was to evaluate the genetic diversity of peach and nectarine cultivars from the Agronomic Institute Prunus germplasm. This assessment was based on inbreeding and coancestry coefficients, considering two cases according to the origin of pollen donor in open pollinations: case I as self-pollinated, and case II as outcrossing. This study provided information regarding the founder cultivars. The historical investigation of the genealogy of 84 cultivars returned up to eight generations. Thirty-one founder cultivars were identified. The inbreeding coefficient of 40 (case I) and 14 (case II) for the cultivars were higher than expected, evidencing some degree of inbreeding. However, the averages for the coancestry coefficients were low (case I: 0.144; case II: 0.087), indicating genetic variability among the cultivars, which may be used in breeding programs.

Resumo em Inglês:

Abstract Quinoa is a self-pollinating species with very small flowers, which hinders efficiency in crossbreeding. Therefore, developing an efficient crossbreeding method should be considered an important step for breeding programs. In this regard, the objective of this study was to obtain hybrids, estimate the rate of natural hybridization, and estimate genetic parameters and agronomic characteristics of the F2 generation. Crossbreeding assays were set up in three environments with four parents, using two methodologies, pot planting and field planting. Morphological markers were used to identify the hybrids, which were self-pollinated to obtain the F2 generation. The results indicated that cross-pollination ranged from 3.81% to 19.88% depending on the planting methodology. The presence of pigmentation was dominant compared to its absence. The most prominent hybrid was obtained from the cross P88 x BX4, showing grain yield of 3000 kg ha-1. Broad-sense heritability was identified with values exceeding 81.27% for all variables.

Resumo em Inglês:

Abstract We evaluated the genetic diversity, coancestry and heritability of an E. benthamii trial. The 115 individuals were genotyped (13 SSR) and had their height and diameter at breast height (dbh) measured. Heritability was estimated using the RR-BLUP and the pairwise kinship coefficient method. An average of nine alleles per locus was observed. The expected heterozygosity (0.655) was similar to the observed heterozygosity, with the estimated inbreeding (0.02) being low. The group coancestry (0.051) demonstrates that the trees are related to some degree. The trees were clustered in five groups using the Evanno’s method. The average kinship within each group ranges from 0.042 to 0.082. The heritability estimated by RR-BLUP was low. The heritability estimated using the kinship coefficients is moderate, reaching estimated genetic gains of 14% for dbh. After knowing how genetic groups are distributed within the population, strategies for collecting, conserving, and using these germplasm resources can be performed.

Resumo em Inglês:

Abstract The aim of this work was to validate markers linked to the SH3 gene of coffee leaf rust (CLR) resistance and use them in assisted selection. Initially, we validated the markers in genotypes already known to carry SH3. Next, we performed phenotype and genotype evaluation for resistance to CLR in coffee plants growing under field conditions. We used Arabica coffee progenies derived from BA-10, which carries the SH3 gene due to introgression of C. liberica. Three SCAR markers (SP-M16-SH3, BA-48-21O-f, and BA-124-12K-f) and one SSR marker (Sat244) linked to SH3 gene were used to amplify the coffee plants’ DNA. Our assessments of markers validation in resistant genotypes, SP-M16-SH3 and BA-124-12K-f, were efficient to identify the SH3 gene. These two markers were used to evaluate the progenies derived from BA-10 and were significantly linked to the phenotype evaluations. The SP-M16-SH3 marker was more efficient, with the advantage of being codominant.

Resumo em Inglês:

Abstract This study evaluated the genetic variability of 34 local rice genotypes from Simeulue Island and Sumba Island, Indonesia, using ISSR and SRAP markers. The amplification of ISSR and SRAP primers produced high percentages of polymorphism, with values of 98.17% and 99.75%, respectively. The result of the UPGMA dendrogram analysis classified the rice genotypes into three groups by ISSR and two groups by SRAP. The ISSR had a higher Resolving Power (RP = 14.66) and Marker Index (MI = 4.61) than the SRAP (RP = 9.13, MI = 3.8). However, the results of the UPGMA dendrogram corresponded to the STRUCTURAL data analysis. The ΔK of STRUCTURAL analysis performed its maximum value when K = 3 by ISSR and K = 2 by SRAP. This study pointed out that ISSR markers were more effective than SRAP markers in evaluating the degree of genetic variability of rice genotypes.

Resumo em Inglês:

Abstract Development of transgenic crops with stable gene inheritance and expression over generations is important for effective deployment at field level. In present study, T1 plants of pigeonpea cultivars AL15 and AL201 were evaluated for the presence and expression of cry1Ab gene and protection against Maruca pod borer. Cry1Ab protein in transgene carrying T1 plants ranged from 0.72 to 0.87 µg/g flower tissue. In vitro insect bioassay demonstrated up to 49.17 and 53.80% loss in larval body weight after four days of infesting T1 transgenic flowers and pods, respectively. Further, no adults emerged from the pupae of larvae fed on transgenic plants 15-537 and 201-344. All T2 progeny plants of 15-537 exhibited cry1Ab presence; likewise, all T3 progeny plants derived from homozygous T2 plant (15-537-5) displayed presence and expression of transgene, thus establishing stable transgene integration in T1 plants, followed by its stable inheritance and expression in T2 and T3 generations.

Resumo em Inglês:

Abstract This study assessed the structure and genetic diversity of rice populations of Southeast Asian varieties, based on quantitative morphological and molecular traits. Population structure analysis revealed four distinct populations as ancestral origin of the varieties in the collection. Some traditional varieties from different countries share the same ancestry, while on the other hand, admixture was observed in the ancestry of some varieties. High diversity in quantitative morphological traits was confirmed in the rice collection. Spikelet fertility and plant height contributed significantly to the diversity.

Resumo em Inglês:

Abstract The objective of this study was to identify cowpea genotypes that fulfill the criteria of high grain yield, adaptability, and stability in the Mato Grosso do Sul (MS) region. Yield data from Value for Cultivation and Use (VCU) trials conducted in the municipalities of Dourados and Aquidauana/MS from March to August 2017 and 2018 were used, totaling four environments. A randomized block design with 14 treatments and four repetitions was adopted. Yield was evaluated by weighing the grains from the usable plot and converting the values to kilogram per hectare. After the analysis of variance, the interaction between genotypes and environments was evaluated by the methodologies of adaptability-stability analysis of Eberhart and Russell, Lin and Binns modified by Carneiro and GGE-Biplot. The genotypes Pingo-de-ouro 1-5-7, Pingo-de-ouro 1-5-5 and Bico-de-ouro 1-5-24 are stable, adaptable and productive for the state according to the complementary use of the methods.

Resumo em Inglês:

Abstract The viability of using inbred progenies, i.e., S1 or S2, in recurrent selection programs for perennial plants was evaluated in comparison with full sibs using the expression of gain from selection. Populations with different genetic properties, were considered in obtaining the estimates, with the population genetic variance always equal to 1 used as reference, as well as different experimental strategies. The estimates of genetic covariances between average additive effects of the alleles and the dominance effects of homozygotes, which occur when S1 or S2 is used, although negative for the lower values of the average allele frequencies, were always smaller than the additive genetic variance. Per unit of time, the total gain from selection with S1 was greater than with S2 and full sibs. However, it is argued that the best strategy is a cycle with S1, followed by a cloned progeny test with full sibs.

Resumo em Inglês:

Abstract The sugary cassava cultivar BRS 438 has high roots yield (with expressive concentration of free sugars), adaptation to mechanized planting, and moderate resistance to bacterial diseases. These characteristics make it an option for production of sugars, alcohol, and animal feed (additive in forage grass silage), among other possibilities.