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The physiological quality is based on the genotype and may be accompanied since the first stages of selection through the study of genetic diversity. The purpose of this study was to evaluate the parental genetic contribution in the seed physiological quality in corn intervarietal crossbreeds. The intervarietal crossbreeds were performed using landraces genotypes, open pollinated varieties and commercial hybrids. The seeds obtained from the crossbreed, their equivalents and parentals were evaluated regarding their water percentage, germination, germination speed rate, accelerated aging, field emergence and electrical conductivity. The seeds obtained in the crossbreed are viable and vivid with heterosis when compared with the parentals. The accelerated aging test was more effective for selecting the strongest genotypes. The canonical variables were useful to group the genotypes that presented similar physiological characteristics. The genotypes MPA 01 x Pixurum 05, MPA 01 x AS1565, MPA 01 x SJC5886, SJC5886 x Pixurum 05 and Fundacep 35 x SCS 154 Fortuna were the best crossbreeds regarding the production of better physiological quality seeds.

-Viability and vigor of seeds are physiological attributes influenced by a myriad of factors including the genotype. Biochemical profiling of maize seeds and its correlation with their physiological quality is of crucial importance in breeding programs that the aim is seeds of better quality. The main goal of this study was to analyze the genetic diversity among maize inbred lines and evaluate the biochemical components that have an important role in physiological quality of seeds. The seeds of the inbred lines and hybrids were submitted to viability test, vigor by the accelerated aging and cold tolerance, and biochemical profiling (total protein content, soluble proteins, total phosphorus, phytate, inorganic phosphorus, starch and soluble sugars). The genetic divergence between the inbred lines found, prompt us to conclude that genetic gains may exist in association with physiological quality of maize hybrids. Seeds with higher inorganic phosphorus and soluble sugars presented superior physiological quality than seeds with lower levels of those compounds.Index terms: vigor, viability, genetic divergence, stored reserves, Zea mays.Perfil bioquímico e seu papel na qualidade fisiológica de sementes de milho RESUMO -A viabilidade e o vigor de sementes são atributos fisiológicos influenciados por uma série de fatores, incluindo o genótipo. O perfil bioquímico das sementes de milho e sua correlação com a qualidade fisiológica são importantes para programas de melhoamento que objetivam obter sementes de melhor qualidade. O objetivo deste estudo foi analisar a diversidade genética entre as linhagens de milho e avaliar os componentes bioquímicos que têm um papel importante na qualidade fisiológica das sementes. As sementes das linhagens e dos híbridos foram submetidas ao teste de viabilidade, vigor pelo envelhecimento acelerado e tolerância ao frio e a determinação do perfil bioquímico (teor de proteína total, proteínas solúveis, fósforo total, fitato, fósforo inorgânico, amido e açúcares solúveis). A divergência genética encontrada entre as linhagens permite concluir que os ganhos genéticos podem existir em associação com a qualidade fisiológica dos híbridos de milho. As sementes com maior teor de fósforo inorgânico e açúcares solúveis apresentaram qualidade fisiológica superior à das sementes com níveis menores desses compostos.Termos para indexação: vigor, viabilidade, divergência genética, reservas armazenadas, Zea mays.

The soybean seeds produced in Santa Catarina have the potential for the application of new marketing strategies because they have superior quality over the minimum standards established by the Brazilian legislation. This potential was verified using time series analysis (TS). The main goal of this study was to characterize the physiological quality of soybean seeds produced in the State of Santa Catarina using data from the last five harvests in order to establish new commercialization strategies based on seed quality. Historical data for germination and vigor were obtained from the 2012/2013 to 2016/2017 harvests, with a total of 4606 lots studied. To validate the historical data, data from the 2016/2017 harvest were included. For this analysis, 100 lots of soybean seeds from the 2016/2017 harvest were collected, and laboratory tests for germination and vigor were performed. The results of the time series analysis showed that, on average, the germination rate ranged from 89 to 93%, with all values being higher than the minimum required for commercialization by the Brazilian legislation. Vigor ranged on average from 82 to 90%. Currently, there is no reference value for vigor in the Brazilian legislation for seed commercialization purposes. Of the total of lots evaluated, 1%, 2%, 21%, and 76% of seeds presented germination < 70%, 70–80%, 80–90%, and > 90%, respectively, whereas 4%, 3%, 7%, 17%, and 69% of the lots presented vigor < 70%, 70–75%, 75–80%, 80–85%, and > 85%, respectively. Considering that 76% of the lots presented germination > 90% and 69% of the lots had vigor > 85%, the lots that presented these percentages were ranked, and 64% were determined to meet high quality standards. Taking into account the 100 sampled lots from the 2016/2017 harvest, 55% presented germination > 90% and 58% had vigor > 85%. In this harvest, 41% of the lots met the standards of at least 90% germination and 85% vigor according to the ranking methodology. This study concludes that due to the stability of climatic conditions, the State of Santa Catarina produces soybean seeds with physiological quality above the minimum standards, which allow the establishment of a minimum vigor standard of 85% for the commercialization of soybean seeds.

Producing high-quality seeds for agroecological agriculture is needed because the plants will be exposed to a diversity of environments and management practices. Sowing times and population densities can influence the quality of seeds produced by landraces.Further, seeds for agroecological cultivation must not be contaminated by transgenes. In this context, it is necessary to know the agronomic performance of landraces outside of the recommended growing period to avoid gene flow with transgenic cultivars. Thus, the objective of this work was to determine the germination rate, vigor and sanitary quality of seeds of maize genotypes cultivated in an agroecological system at different sowing times and densities. A split-split-plot design was used in the 2016/2017 and 2017/2018 growing seasons. The physiological quality evaluation was based on germination and vigor tests, and the sanitary quality was obtained by visually examining the seeds. The results showed a significant simple effect of genotype, sowing time and density, as well as double and triple interactions among factors for all evaluated traits. The most suitable time for sowing the corn landraces evaluated in an agroecological system in western Santa Catarina is September, when the seeds exhibited the highest percentage of germination and vigor and there was a lower incidence of pathogens. At this time, a density of 55,000 plants•ha -1 had the best result for germination. Late sowing was tested to avoid gene flow from transgenic varieties that usually are sown in September, but the results indicated penalties, such as a decrease in seed yield and quality.

Representative seed lot sampling is important in analyzing seed quality. This study aimed to determine whether sampling during processing and after packaging using samplers interferes in analyzing the physiological quality and health of soybean seed lots. The study was conducted with six and twelve soybean seed lots produced in the 2017/2018 and 2018/2019 growing seasons, respectively. Two sampling methods were used, according to the Rules for Seed Testing: a) sampling during processing; b) sampling of seed lots stored in bags using a sampler. Seed quality was assessed by germination percentage, accelerated aging, and tetrazolium tests to determine vigor, and seed health using the blotter test. Sampling during processing and after storage in bags differ in the expression of seed vigor and health. Seed lot homogeneity is essential to determine the difference between sampling methods. Sampling in the processing flow is more representative and may be indicated for the germination test.

Storage reserves composition is directly related to the manifestation of seed vigor. However, the physiological potential expression in inbred lines, as well as hybrids from the storage reserves hydrolysis, is not clear. Thus, the aim of this study was focused on verifying if there are differences in the hydrolysis of seed storage reserve of maize inbred lines or hybrids during germination, and also checking if the changes in hydrolysis are associated with seed vigor. The seeds of inbred lines and hybrids were submitted to germination test, vigor by accelerated aging and cold tolerance. Biochemical profiling (total protein content, soluble proteins, phytate, inorganic phosphorus, starch, and soluble sugars), was temporally determined at 0 h (quiescent seeds), 12 h, 24 h, 30 h, and 48 h after imbibition. The seeds of inbred lines showed a longer time for root protrusion and less vigor when compared to hybrids. The highest hydrolysis rates in inbred lines were observed in phase I and at the end of phase II of germination. In hybrids, the rates remained, on average, constant throughout germination. The greatest differences in the hydrolysis of reserve compounds occur in phase II of germination and differentiate the germination metabolism of hybrids and inbred lines.

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