Soybean [Glycine max (L.) Merril] is one of the main crops produced worldwide, and on‐farm yields have increased considerably in the last decades in Brazil. We evaluated the genetic gain for agronomic, phenological, and end‐use quality traits in 29 cultivars in the South Region, and in 38 cultivars in the Midwest Region in Brazil, released from 1966 to 2011. Field trials were conducted in Macroregions 1, 2, and 4, in 2016–2017, 2017–2018, and 2018–2019 crop seasons. The best linear unbiased predictors (BLUP) of the cultivars were obtained for each trait using a linear model. The BLUPs were regressed with the year of release using linear and quadratic regression models. The rates of genetic gain for seed yield ranged from 11.98 to 15.31 kg ha–1 yr–1 (0.33 to 0.42% yr–1) in the South Region, and from 13.58 to 21.84 kg ha–1 yr–1 (0.47 to 0.77% yr–1) in the Midwest Region. New cultivars presented taller plants and more seed oil content, oil and protein yield, and lower seed weight, days to flowering, days to maturity, and seed protein content than old cultivars in the South Region, although with differences between the Macroregions. In the Midwest Region, new cultivars showed higher seed oil content, oil and protein yield, and lower bottom pod height and seed protein content than old cultivars. Our results showed that breeding programs have been efficient to improve soybean yield and other traits across the years, without yield plateaus in sight.

Asian soybean rust (ASR) causes large reductions in soybean yield, affecting the entire grain market. With low fungicide e ciency, the use of resistant cultivars can be an economical, safe, e cient, and sustainable control alternative. However, the great variability and aggressiveness of ASR and the use of Rpp genes are limited. Thus, gene pyramiding is a promising strategy for the development of cultivars with high resistance to a greater number of isolates. Thus, the aim of this study was to evaluate sister lines with different pyramided Rpp gene for resistance to Phakopsora pachyrhizi and identify which combination of Rpp genes had higher levels of resistance under eld conditions. All Rpp-pyramided lines showed higher levels of resistance, with signi cant reductions in sporulation levels (SL), number of uredinia per lesion (NoU), and frequency of lesions with uredinia (%LU), compared to the resistance sources PI200487 (Rpp5), PI200492 (Rpp1), PI230970 (Rpp2), PI459025A (Rpp4), PI506764 (Rpp3, 5), PI587880A (Rpp1-b), PI594538A (Rpp1-b), and PI594723 (Rpp1-b). Rpp-pyramided lines carrying Rpp1-b + Rpp1-b, Rpp2 + Rpp1-b, Rpp4 + Rpp1-b, and single gene Rpp1-b were classi ed as "highly resistant". Furthermore, one sister line, 52117-57 (Rpp2 + Rpp1-b), showed immunity under eld conditions. The Rpppyramided genes are an alternative for achieving high resistance levels against ASR.

Soybean (Glycine max (L.) Merrill) is one of the most important commodities in the world, with grains that show variations in their chemical composition, mainly in oil and protein content. These variations can be related to genotype (G), environment (E), and G × E interaction. Thus, the objectives of this study were to determine the environments which maximize oil and protein yields, and to identify potential soybean cultivars that have increased grain yield, and oil and protein content in high-and low-altitude environments. Twenty-eight soybean cultivars were evaluated at high (846–963 m, Cfb climate) and low (336–480 m, Cfa climate) altitude environments, in the 2017/18 and 2018/19 crops, for grain yield, thousand grain weight, and oil and protein contents and yields. Growing environment affected the chemical composition of soybean grains. Altitude had a positive effect on protein content and a negative effect on oil content. The high-altitude environment increased the protein content by 6.15% (380 g kg-1), whereas the low altitude environment promoted an increase of 5.58% in oil content, with a mean value of 220 g kg-1. We identified soybean cultivars with potential for greater oil and protein yields in high-and low-altitude environments. Knowledge of the associations between environments and the chemical composition of soybean grain is valuable for developing direct breeding efforts, recommending cultivars and growing locations, in order to meet the demand of the oil and protein market

Asian soybean rust (ASR) causes large reductions in soybean yield, affecting the entire grain market. With low fungicide efficiency, the use of resistant cultivars can be an economical, safe, efficient, and sustainable control alternative. However, the great variability and aggressiveness of ASR and the use of Rpp genes are limited. Thus, gene pyramiding is a promising strategy for the development of cultivars with high resistance to a greater number of isolates. Thus, the aim of this study was to evaluate sister lines with different pyramided Rpp gene for resistance to Phakopsora pachyrhizi and identify which combination of Rpp genes had higher levels of resistance under field conditions. All Rpp-pyramided lines showed higher levels of resistance, with significant reductions in sporulation levels (SL), number of uredinia per lesion (NoU), and frequency of lesions with uredinia (%LU), compared to the resistance sources PI200487 (Rpp5), PI200492 (Rpp1), PI230970 (Rpp2), PI459025A (Rpp4), PI506764 (Rpp3, 5), PI587880A (Rpp1-b), PI594538A (Rpp1-b), and PI594723 (Rpp1-b). Rpp-pyramided lines carrying Rpp1-b + Rpp1-b, Rpp2 + Rpp1-b, Rpp4 + Rpp1-b, and single gene Rpp1-b were classified as “highly resistant”. Furthermore, one sister line, 52117-57 (Rpp2 + Rpp1-b), showed immunity under field conditions. The Rpp-pyramided genes are an alternative for achieving high resistance levels against ASR.

The objective of this work was to evaluate the grain yield potential of modern soybean (Glycine max) cultivars subjected to high- and low-input management levels on different sowing dates, in the southwestern region of the state of Paraná, Brazil. The experiment was carried out in the 2017/2018 and 2018/2019 crop seasons in the municipality of Itapejara D’Oeste. Five soybean cultivars (BMX Zeus IPRO, BMX Ativa RR, BMX Lança IPRO, NS 5445 IPRO, and NA 5909 RG) were evaluated in four environments formed by the combination of input management levels (high and low) and sowing dates (first and second). The experimental design was a randomized complete block with three replicates. The evaluated traits were: grain yield potential (kg ha-1), in the R5 phenological stage; and grain yield (kg ha-1) and its components, in the R8 stage. Cultivar, sowing date, and input management are determinant for maximizing grain yield potential. In the first sowing date, in October, the BMX Zeus IPRO cultivar shows a better response to the high level management, with a higher yield potential in the R5 stage (19,682 kg ha-1) and a higher grain yield (8,248 kg ha-1), whereas NA 5909 RG shows the best results with the low input management.