Stylosanthes macrocephala M. B. Ferr. et S. Costa é uma leguminosa utilizada sob consorciação em pastagens, adubação e recuperação de áreas degradadas. A falta de características morfológicas e agronômicas estáveis e de informações ecogeográficas dos locais de coleta dos acessos tem dificultado o melhoramento genético da espécie. A fim de obter descritores ecológicos, moleculares e avaliar a variabilidade genética da coleção de S. macrocephala, 87 acessos foram analisados com o auxílio do Sistema de Informações Geográficas (SIG) e de marcadores moleculares RAPD. Os acessos provieram de sete Estados, cinco bacias hidrográficas, sete tipos de vegetação e sete tipos de solos. As altitudes dos locais de coleta variaram de 1 a 1.298 m e a pluviometria anual média de 550 a 2.870 mm. A variabilidade de descritores ecológicos sugeriu diversidade adaptativa na coleção. Com base em 161 marcadores RAPD, verificou-se que as distâncias genéticas entre os acessos de S. macrocephala variaram entre 0,02 e 0,42. Com base nessas distâncias, dez grupos de similaridade genética foram estabelecidos. Observou-se tendência de separação por bacias hidrográficas e elevada variabilidade genética entre os acessos coletados nos estados da Bahia e de Minas Gerais. A alta variabilidade genética da coleção de S. macrocephala evidencia a importância desses acessos para futuros trabalhos de melhoramento genético.

Gamba grass (Andropogon gayanus Kunth) is a promising forage alternative for Brazil’s Cerrado regions, attracting increasing research interest due to its potential to complement or replace widely planted species such as Urochloa and Megathyrsus. Despite the release of three cultivars, significant improvements in dry matter (DM) yield and forage quality are needed to fully realize its agronomic potential. This study aimed to evaluate genetic variability, estimate narrow sense heritability, and predict expected genetic gains for DM yield and key forage quality traits in two gamba grass populations derived from the cultivars BRS Sarandi and Planaltina. Trials were established in spring 2017 in Planaltina, DF, and evaluated during February–March 2018 and January–March 2019. Crude protein (CP), neutral detergent fiber (NDF), acid detergent fiber (ADF), cellulose (CEL), and hemicellulose (HEMIC) were quantified alongside DM yield. BRS Sarandi exhibited higher CP (12.3% vs. 9.8%) and lower NDF (57.1% vs. 63.4%), ADF (36.2% vs. 41.5%), CEL (20.8% vs. 23.7%), and HEMIC (20.9% vs. 21.9%) compared to Planaltina, while DM yield did not differ significantly between populations (4.57 t·ha⁻¹ vs. 4.50 t·ha⁻¹ per harvest, p > 0.05). Heritability estimates for individual harvests ranged from 0.31 to 0.68 for DM yield and 0.28 to 0.62 for quality traits, whereas multi-harvest models across years yielded lower estimates (0.07–0.27). Expected annual genetic gains were modest, with the highest predicted increase for CP (0.45% per year) and the largest decrease for NDF (−0.78% per year), reflecting the quantitative nature of trait inheritance and strong environmental influence. This study provides novel insights by simultaneously comparing two populations for multiple harvests and quantifying both yield and detailed forage quality traits, offering practical guidance for gamba grass breeding strategies. Results indicate that breeding programs should prioritize multiple selection cycles, precise phenotyping, genotypic and potentially genomic selection to accelerate improvement in both DM yield and forage quality, overcoming the constraints of low heritability and multi-trait selection.

Gamba grass (Andropogon gayanus Kunth) is a tussock-forming forage species adapted to acid soils of Brazilian savannas and cultivated for grazing pastures. Four decades since its release, Planaltina prevails as the most commercialized cultivar of the species, even though the new cultivar BRS Sarandi could be a better alternative for Gamba-grass-based farms by presenting a greater leaf:stem ratio. The objective of this study was to evaluate the average daily live weight gain (ADG) of Nellore bulls (Bos indicus) for two Gamba grass cultivars—Planaltina and Sarandi. The experiment was conducted in Planaltina, Federal District, Brazil, for 3 years, namely 2018, 2018–2019, and 2020. The experimental design was a completely randomized block design with two treatments and three replicates, each one continuously stocked at three stocking rates (SR)—1.3, 2.6, and 4 young bulls/ha. Canopy height (CH), forage mass (FM), plant-part proportion (green leaf, stem, and dead material), and nutritive value were evaluated. In 2018, mean ADG for Sarandi pastures was greater (0.690 kg/bull/d) than that of Planaltina (0.490 kg/bull/d) (p < 0.10). In the subsequent year (2018–2019), there was no effect of cultivar (p > 0.10), while in 2020 the ADG was again affected by cultivar (p < 0.10), confirming the advantage of Sarandi (0.790 kg/bull/d) over Planaltina (0.650 kg/bull/d). In 2018 and 2020, the percentage of stems for Sarandi was about 3–6 pp less than for Planaltina (p < 0.10). As well as for stems, Sarandi pastures presented a shorter CH in 2028 and 2020 (6–7%) (p < 0.10). The positive high correlation of leaf:stem ratio with ADG (r = 0.70) probably predisposed the superiority of Sarandi over Planaltina. The distinguishing plant-part composition of Sarandi canopy promotes increasing weight gain of beef cattle when compared to cv. Planaltina.

Stylosanthes scabra Vogel is a tropical legume grown in dry tropical and subtropical environments. The objective of this research was to evaluate the genetic diversity of forage quality traits for 80 accessions of S. scabra. Seven plants from each accession were planted in a single-line plot with no replicates at Embrapa Cerrados, Brazil. All plants were harvested 90 days after planting. Crude protein (CP), in vitro dry matter digestibility (IVDMD), neutral detergent fibre (NDF), acid detergent fibre (ADF), lignin (LIG), hemicellulose (HEMIC) and cellulose (CELLU) were estimated. Data were submitted to principal component analysis (PCA) and a cluster analysis was performed to identify groups of similarity. Simpson and Shannon–Weaver diversity indices estimated the genetic diversity. The average values of CP, IVDMD, NDF, ADF, LIG, HEMIC and CELLU were 220g/kg, 560g/kg, 516.8g/kg, 368g/kg, 69.4g/kg, 148.8g/kg and 298.6g/kg, respectively. There was a significant difference among collection sites for IVDMD, ADF and CELLU. The first two principal components accounted for 73% of the total variation. The 80 accessions resulted in four clusters, among which significant differences were observed for CP, IVDMD and ADF. Group IV, with 24 accessions, had the highest CP and IVDMD concentrations and the lowest ADF concentration, being the highest-quality forage group. Diversity indices were 0.78 and 0.81 for Simpson’s and Shannon–Weaver’s, respectively. In conclusion, there is genetic diversity for forage quality traits among S. scabra.

This study aimed to evaluate the morphological diversity of 22 Crotalaria accessions conserved in the Embrapa Cerrados germplasm bank, Brazil, with emphasis on their potential use in breeding and genetic resource management. Sixteen morphological descriptors were analyzed, revealing substantial phenotypic variation among accessions. Plant height ranged from 45 to 146cm, and leaflet and seed traits also showed broad variation, reflecting a wide adaptive spectrum. The Shannon–Weaver (H) and Simpson (D) diversity indices indicated consistently high diversity across traits (mean H = 0.964; mean D = 0.940), confirming the existence of a rich genetic base within the collection. Principal component analysis showed that the first two components explained 63.72% of total variance, with reproductive traits such as seed length, seed width, and 100-seed weight contributing most to variation among accessions. Cluster analysis grouped the accessions into five distinct morphological clusters, identifying genotypes with superior plant vigour, leaf area, or seed characteristics as potential parents for future breeding programmes. The observed morphological variability highlights the significant genetic diversity within Crotalaria germplasm, supporting its value for selection, hybridization and conservation. The combination of diversity indices and multivariate analyses provides a robust framework for identifying promising accessions for breeding programmes targeting biomass production, seed yield and environmental adaptation. These findings reinforce the importance of maintaining and characterizing germplasm collections as strategic reservoirs for sustainable crop improvement and the long-term conservation of genetic resources.

Tropical forage seed production is strategically important to Brazil, and integrated crop-livestock-forest systems create a continuous demand for superior Urochloa ruziziensis cultivars. Optimizing commercial seed yield and quality is challenging, due to the inherent complexity of reproductive traits, seed dormancy, and highly variable seed filling. This study aimed to assess the phenotypic variability and correlations among 24 U. ruziziensis genotypes previously selected for high forage yield. Plants were evaluated for key flowering traits, filled seed mass, seed filling percentage, seed viability, germination rates, and seed dormancy. The results confirmed the existence of broad and significant phenotypic variability among the tested genotypes across all components of yield, quality, and dormancy, showing substantial potential for genetic improvement. Crucially, strong positive correlations were established between essential flowering components, such as the number of inflorescences per plant, and subsequent filled seed mass and seed viability. This study successfully identified elite genotypes exhibiting superior combined yield and quality, as well as specific genotypes with notably low dormancy. The identified genetic diversity and trait correlations provide criteria for guiding selection efforts in similar environments for U. ruziziensis breeding programs.