Resumo em Inglês:

Abstract Maize exhibits extensive variability in vegetative cycle length (VCL), a trait essential for environmental adaptation. This study investigates relationships among genome size, knob heterochromatin content, and VCL in three inbred lines with contrasting flowering times and their F1 hybrids. The latest-flowering line (Floury-2) exhibited the highest DNA and knob heterochromatin contents, whereas the earliest-flowering line (Gaspé) showed the lowest values. Hybrids displayed intermediate values, consistent with an additive inheritance pattern. Significant positive correlations among DNA content, knob content, and VCL were detected across parental lines and hybrids. Within the limited scope of this study, the results suggest that variation in genome size and knob heterochromatin content may influence cell cycle duration and, consequently, flowering time. By integrating cytogenetic and hybrid analyses, this study reveals a cytogenetic basis for flowering time variation and highlights heterochromatin content as an accessible tool for breeding maize adapted to diverse environments.

Resumo em Inglês:

Abstract Genotype × environment (G×E) interaction is a primary challenge in plant breeding. This study integrates envirotyping with genetic modeling to dissect G×E for maize yield using the Genomes to Fields dataset. We utilized PaCMAP dimensionality reduction to classify 272 environments into four target populations of environments, which segregated into two mega-environments (Southern and Northern U.S.). A strong crossover interaction was detected between these mega-environments, resulting in low performance stability (quantified by the S index), primarily driven by an inverse relationship between growing degree days and silking, as well as yield: longer-cycle hybrids were advantageous in the South, while shorter-cycle hybrids excelled in the North. Our findings provide quantitative evidence that this phenological response, linked to photoperiod sensitivity, is a key mechanism underlying the G×E interaction. This framework offers a robust tool for defining breeding targets and accelerating genetic gain.

Resumo em Inglês:

Abstract Selecting grapevine rootstocks that are tolerant to drought has become crucial for the sustainability of viticulture. This study evaluated the quantitative and molecular genetic variability of eight rootstocks subjected to progressive water depletion while cultured in a greenhouse. Several plant mass traits were analyzed, and six SSR markers were used to assess molecular diversity. While heritability for leaf traits varied, stem diameter exhibited a distinct pattern where genotypic differentiation and heritability estimates increased significantly under severe water deficit, ensuring reliable selection accuracy. Additionally, our BLUP analysis indicated that clones IAC 313 Tropical, IAC 766 Campinas, and Paulsen 1103 performed best by the end of the stress period. The SSR analysis grouped the genotypes together while revealing a high genetic diversity among all the rootstocks (He > 0.70). We concluded that late-stage stem diameter was a reliable but indirect selection criterion for drought tolerance.

Resumo em Inglês:

Abstract The integrated analysis of morphological and molecular markers represents an effective approach for estimating genetic variability in ornamental species. In the present study, 37 genotypes of Adenium obesum resulting from a single biparental cross were evaluated based on morphofloral traits and ISSR markers. Morphological characterization revealed a predominance of magenta corollas (64.9%), mostly single or double flowers (95%), and variegation in 81% of the genotypes. The mean number of flowers per genotype was 14 and the caudex diameter was classified as “thick” in 20 individuals (> 71 mm). The amplification process generated 97 loci, resulting in 100% polymorphism and an average of 6.47 polymorphic bands per primer. A combined analysis of the morphological and molecular data revealed moderate correspondence between the clustering patterns (entanglement index = 0.582). The results showed that the full-sibling family was genetically diverse and that this diversity could be used to identify elite genotypes.

Resumo em Inglês:

Abstract Melon is the most economically important cucurbit in the Brazilian Semiarid region, where recent efforts have focused on product diversification through the development of new melon types. This study aimed evaluate Tiger melon lines using the FAI-BLUP and MGIDI indices to identify genotypes combining high yield and quality for advancement in the breeding program. Twenty-four lines were evaluated in two trials conducted in a randomized block design with three replications. The following traits were evaluated: fruit yield, number of fruits per plant, mean fruit weight, pulp thickness, pulp firmness, and soluble solids. Genetic gains were observed for all traits. For the MGIDI index, gains ranged from 14.9% for pulp thickness to 72.5% for fruit weight. For the FAI-BLUP index, gains ranged from 0.39% for fruit yield to 26.36% for fruit weight. Based on both indices, lines TC-02, TC-03, TC-14, and TC-22 were identified as promising for breeding.

Resumo em Inglês:

Abstract ​Describing the growth of pepper plants is essential for efficient management and the selection of superior genotypes. The objective of this study was to fit nonlinear growth models for the height and crown diameter of ornamental pepper accessions under heat stress. Height and crown diameter were evaluated every four days in two environments: (i) a greenhouse with humidity and temperature control and (ii) a greenhouse without control of these factors. The Logistic, Exponential, Gompertz, Richards, and Von Bertalanffy models were fitted. The results indicate that the choice of model depends on the characteristic measured and on the environment. The Gompertz, Richards, and Logistic models satisfactorily described plant height, while the Von Bertalanffy (R²= 0.99) model better represented the behavior of crown diameter under heat stress, characterizing a gradual deceleration of growth. These models should be used to estimate parameters that assist in the selection and management of ornamental pepper plants.

Resumo em Inglês:

Abstract Soybean breeding in Africa is constrained by environmental heterogeneity and strong genotype-by-environment (G×E) interaction, which limits the identification of high-performing and stable genotypes. We evaluated 145 soybean genotypes across 24 environments in seven African countries for grain yield (GY), number of days to maturity (NDM), 100-grain weight (W100), oil content (OIL), and protein content (PROT). Likelihood ratio tests indicated significant genotype, environment, and G×E effects for all traits. GY ranged from 1.404 to 3.391 kg ha⁻¹, with variation in maturity and grain composition associated with altitude and cropping season. Genetic correlations revealed important trade-offs, including positive associations among GY, NDM, and W100, and antagonism between OIL and PROT. Multi-trait selection with 10% intensity identified 14 genotypes closest to the ideotype, with expected gains of 15.7% in GY and favorable responses in the other traits. These findings demonstrate the effectiveness of multi-trait, multi-environment strategies for soybean improvement in Africa.

Resumo em Inglês:

Abstract Asian soybean rust (ASR) is a major threat due to its aggressiveness, fungicide tolerance, and ability to overcome resistance genes. Breeding high-yielding cultivars under ASR pressure presents challenges, including low early selection accuracy and managing several lines. This study evaluated whether early agronomic traits could predict yield in later generations under ASR. Traits assessed included seed yield, days to flowering and maturity, plant height, and 50-seed weight. F2 or F2:3 data were used in regression and machine learning models to predict yield in F2:5 progenies. Similar R² values across approaches suggested a mainly linear relationship among predictors. Using F2:3 data improved R², especially for flowering, maturity, and height. Univariate models with these traits performed best, reaching R² values up to 52.12%. These models can improve early selection and reduce the breeding workload.

Resumo em Inglês:

Abstract The selection of adapted and stable soybean genotypes for the Brazilian Cerrado is hindered by the complex genotype x environment (G x E) interaction. This study aimed to compare the effectiveness of the REML/BLUP and GGE Biplot. Yield data from 33 genotypes in 44 environments (2019-2020 and 2020-2021 growing seasons) were analyzed. The results indicated a significant G x E interaction and high selective accuracy (0.86), validating the selection precision. Both methodologies proved to be effective and concordant in identifying a group of elite genotypes (commercial checks G3 (BASF), G6 (BASF), G4 (BASF), and the experimental lines G17 (BASF) and G18 (BASF)). REML/BLUP provided the quantitative basis for selection, whereas the GGE Biplot elucidated the formation of mega-environments and the positioning of genotypes relative to the ideotype. It is concluded that the methodologies are complementary, enhancing decision-making and maximizing genetic gains in soybean breeding programs for the Cerrado.

Resumo em Inglês:

Abstract We characterized 12 Solanum species using CMA/DAPI banding and/or genome size estimation (1C value) within a phylogenetic perspective. Here, we reported new Constitutive Heterochromatic (CH) data for S. andreanum, S. peruvianum and S. paludosum and new 1C value for S. corneliomulleri and S. andreanum. CH ranged from two (S. viarum) to 42 bands (S. paludosum). Potato species exhibited a higher number of CH blocks, whereas Leptostemonum species generally had fewer blocks, except for S. paludosum. However, no relationship between heterochromatin and evolutive diversification within the genus could be inferred. Mean 1C value varied from 1.0 pg in S. melongena (diploid) to 1.80 pg in S. laciniatum (octaploid), with moderate correlation (r = 0.69) with the ploidy level of the species. Our data contribute to understanding genetic and cytogenetic diversification within Solanum in a phylogenetic context and are relevant to species characterization, supporting future genetic breeding programs of the genus.

Resumo em Inglês:

Abstract Increasing rice production can be achieved by increasing spikelet number and shortening the flowering period. This study evaluated the agronomic performance, genotype stability, and molecular profiles of 14 rice lines derived from backcrosses of Conde-an Indonesian nationally released variety targeted for improvement-with IR64, which carries qTSN4, a locus that enhances spikelet number, or qDTH8, which shortens days to heading. Five Conde-qTSN4 lines (A8-5, A16-5, B6-2, B12-2, and B22-1) exhibited statistically increased total grains (both filled and empty) per panicle, while two Conde-qDTH8 lines (G64 and G142) matured earlier. AMMI and GGE biplot analyses identified Conde and three qTSN4 lines (A8-5, B12-2, B15-2) as stable across nine environments. Molecular analysis confirmed the presence of qTSN4 or qDTH8 alleles, with all lines carrying the Xa7 resistance gene. The qTSN4 and qDTH8 loci contributed to yield improvements of 3% and 12.5%, respectively, demonstrating their potential to enhance rice productivity in Indonesia.

Resumo em Inglês:

Abstract BRS TR209 is a new wheat cultivar from Embrapa recommended for wheat-growing regions 1 (RS, SC, and PR) and 2 (RS and SC) in southern Brazil. It is a semi-dwarf cultivar, shows resistance to pre-harvest sprouting (PHS), and has strong gluten strength and white flour.

Resumo em Inglês:

Abstract ‘BRS Savana (BRS TR135)’ is a wheat cultivar with early maturity, good flour quality, and moderate resistance to wheat head blast (conferred by the 2NS segment). This cultivar is recommended for cultivation under rainfed conditions in central Brazil (MG, GO, DF, and part of SP, MS, MT, and BA).

Resumo em Inglês:

Abstract We formalize “enviromic markers” as modeling units parallel to DNA markers, but herein for genotype-environment (G × E) prediction. Four operational premises (linearity; site potential; heterogeneous favorability; and envirotypic covariates (ECs)-genotype-dependence) are presented to enable their use in linear mixed models and also to motivate four construction strategies: (i) using raw environmental covariates as linear markers; (ii) applying transformations to capture mild nonlinearities; (iii) deriving ecophysiological functions; and (iv) engineering markers with Artificial Intelligence (AI) models which learn nonlinear environment → phenotype mappings for linear downstream use. Environmental data quality control is detailed, including checks of spatial coverage and resolution, variance within the TPE, collinearity control, and spatial/temporal validation without leakage. Envirome data are linked with GIS to compute environmental kernels, quantify covariate shifts, and deliver pixel-level predictions with uncertainty diagnostics. The framework clarifies assumptions and standardizes the use of enviromic markers for predictive breeding analyses.

Resumo em Inglês:

Abstract Accumulation of tocopherol and tocotrienol antioxidant compounds in rice seeds depends on enzymes involved in their biosynthetic pathways, including methionine adenosyltransferase (MAT). The aim of this study was to develop molecular markers for MAT gene LOC_Os11g15410 and evaluate associations between its polymorphisms and the accumulation of tocopherol and tocotrienol congeners in uncharacterized rice germplasm. Using high-resolution melting (HRM) analysis, we identified two consecutive SNPs (Chr11:8733700 bp and Chr11:8733701 bp) defining two haplotypes (AA and GG), and a novel 49-bp indel spanning from the second exon to the third intron. A panel comprising twelve rice samples and four Oryza sativa L. accessions was evaluated. The GG haplotype combined with the indel was associated with higher accumulation of δ and γ congeners, which are intermediates in the biosynthetic pathway. In contrast, the AA haplotype without the indel was associated with β and α congeners, which are end products of the MAT-mediated pathway.