Dynamics of reserves of soybean seeds during the development of seedlings of different commercial cultivars

Abstract

-Physiological quality and vigor of the seeds comprise properties that determine a high level of activity and performance during germination and seedling emergence, having a direct relation with the establishment of the stand of a crop. In this context, the assessment of seedling development, including the analysis of the seed reserves mobilization are a reliable method to investigate the physiological potential of seed lots. In this preliminary study, the aim was to investigate the dynamics of seed reserves mobilization of a sample of soybean commercial cultivars. By means of the seedling length bioassay and weight of dry matter of seeds, cotyledons, hypocotyls and radicles, information on the reserves mobilization during the germination process was obtained. Data were subjected to analysis of variance and Scott and Knott test, and afterwards, phenotypic correlations between traits were obtained. The results have shown that the dry matter of seeds, reserves reduction of seeds and dry matter of seedlings are positively correlated, and thus, seeds containing more reserves may be more effective during the early development of seedlings. In contrast, reserve reduction of seeds and conversion efficiency of the seeds reserves in the dry matter of seedlings are negatively correlated.Index terms: Glycine max (L.) Merrill, germination, seedlings, reserves mobilization. Dinâmica de reservas das sementes de soja durante o desenvolvimento de plântulas de diferentes cultivares comerciaisRESUMO -Qualidade fisiológica e vigor compreendem propriedades das sementes que determinam alto nível de atividade e desempenho durante a germinação e emergência das plântulas, tendo relação direta com o estabelecimento do estande de uma lavoura. Neste contexto, a avaliação do desenvolvimento das plântulas, incluindo análise da mobilização de reservas das sementes pode se constituir em um método confiável para investigação do potencial fisiológico de lotes. Neste estudo preliminar, objetivou-se investigar a dinâmica de reservas em sementes de cultivares comerciais de soja. Por meio do teste de comprimento de plântulas e peso de massa seca de sementes, cotilédones, hipocótilos e radículas foram obtidas informações sobre a mobilização de reservas durante o processo de germinação. A massa seca de sementes, redução de reservas de sementes e massa seca de plântulas estão positivamente correlacionados entre si, e, logo, sementes contendo mais reservas podem apresentar maior vigor durante o desenvolvimento inicial de plântulas. Em contrapartida, redução de reserva de sementes e eficiência na conversão de reservas das sementes em massa seca de plântulas são negativamente correlacionadas.Termos para indexação: Glycine max (L.) Merrill, germinação, plântulas, mobilização de reservas.

Late seed maturation improves the preservation of seedling emergence during storage in soybean

“…Afterwards, the elongation slowed down and a plateau was reached after 14 days. Such kinetics of elongation are in accordance with previous work on legume seeds (Pierre et al, 2014). For logistic reasons, 7 days of darkness was retained for further experiments considering that the elongation at that age represented 79% of the maximum value recorded at 28 days.…”

“…Root length was also around 16 cm and there were no significant changes during maturation. In legume seed such as soybean, elongation capacity of the cells is preestablished during embryogenesis (Sánchez-Bravo et al, 2008;Pierre et al, 2014). Thus in our material, elongation capacity following forced drying was already gained during seed filling.…”

“…To avoid the influence mechanical strength of the seed coat on elongation capacity of the radicle during germination, seeds with an emerged radicle ranging from 0.3 to 0.7 cm were preselected and transferred into darkness (Pierre et al, 2014). As 24 hours separated the first from the last germinating seeds ( Figure 1A), three transfers of germinated seeds were performed successively.…”

“…Other traits such as speed of germination, seedling emergence and absence of abnormal seedlings are also important to establish a crop in the field and can be used to evaluate seed vigor (Yagushi et al, 2014;Finch-Savage and Bassel, 2016;Marcos-Filho, 2016). Successful seedling emergence in epigeal species such as soybean depends on strong and fast elongation of the hypocotyl and the root system that is sustained by the mobilization of energy reserves and sugar mobilization until the embryonic stem reaches the light and cotyledons start photosynthesis (Lilley et al, 2012;Zhong et al, 2014;Pereira et al, 2015). After radicle emergence beneath the soil surface, initial growth is essential to maintain contact with the soil moisture as the surface layers are drying out (Finch-Savage and Bassel, 2016).…”

Strategy for selection of soybean genotypes tolerant to drought during germination

“…It is important to note that these features when present genetic variability can be considered in breeding programs (Pereira et al, 2015) and a strategy on the selection of superior genotypes.…”