Ranges of Vigor Based on the Electrical Conductivity Test in Dehulled Sunflower Seeds

Abstract

Electrical Conductivity (EC) is a promising vigor test since it produces fast laboratory results. In sunflower, the leakage of electrolytes from the pericarp may interfere with exudates from embryo tissues. The aims of this work were (1) To determine the utility of the EC test using dehulled (without pericap) sunflower seeds to evaluate the vigor in different genotypes, exposed to contrasting seed filling period and storage conditions, (2) To explore the relationship between EC and germination values near post harvest and across storage period and (3) To propose ranges of vigor through EC, so as to categorize sunflower seeds lots. Seeds of commercial hybrids differentiated by acid composition (high and standard oleic acid), exploring contrasting seed filling period and storage conditions, were evaluated by EC, Tetrazolium (TZ-V) and Germination (G), near post harvest time and during storage period (1, 5, 9, 13 and 19 months). An independent set of 18 genotypes, stored during 1-108 months, were also analyzed for EC and G. Electric conductivity in dehulled seeds was effective to identify vigor differences of genotypes in different seed filling period and storage conditions. A general relationship between the loss of germination and vigor was established for sunflower. The ranges of vigor based on EC proposed for sunflower seeds classification were <70 µs cmG 1 gG 1 for high, 70-110 µs cmG 1 gG 1 for intermediate and >110 µs cmG 1 gG 1 for low vigor levels. It is the first report based on EC ranges to categorize the seed vigor of sunflower seeds lots.

Physiological potential of soybean seeds and its relationshipto electrical conductivity

“…Similar classifications were mentioned for soybean seeds by Vieira (1994), indicating seed lots with EC values of 60-70 μS.cm -1 .g -1 as high vigor, and from 70 to 80 μS.cm -1 .g -1 as medium vigor. For sunflower seeds, Szemruch et al (2015) proposed EC < 70 μS.cm -1 .g -1 as high vigor, 70 to 110 μS.cm -1 .g -1 as intermediate vigor and EC > 110 μS.cm -1 .g -1 as low vigor.…”

“…Studies to determine reference values for the purpose of differentiating the vigor of seed lots by the electrical conductivity test have been performed for some species, such as sunflower (Szemruch et al, 2015) and soybean Vieira et al, 2004;Colete et al, 2004).…”

Non-destructive identification of physical damage in mung bean (Vigna radiata L.) seeds by X-ray image analysis

“…These tests include electrical conductivity, pH of the exudate and potassium leakage, that can be used efficiently to evaluate the seed vigor of different species (GUOLLO et al, 2016;SZEMRUCH et al, 2015;ZUCARELI et al, 2013). It is important to emphasize that, despite providing fast and reliable results, the main disadvantage of these rapid tests is that they are destructive, not allowing reuse of the seeds for other evaluations.…”

Electrical conductivity test in the evaluation of physiological quality in seeds of eggplant (Solanum melongena L.)

“…Dicho análisis reveló confiabilidad en los resultados ya que dicho coeficiente resultó similar a los reportados por Silva et al (2013b) en fríjol e inferior a los encontrados en berenjena por Alves et al (2012) y Lopes et al (2013). A nivel de cultivares se detectó diferencias altamente significativas (Tablas 2 y 3), lo que puede obedecer a una mayor cantidad de lixiviados del cultivar CO015, como consecuencia del deterioro de las membranas celulares, a causa de la humedad como fue evidenciado por Alves et al (2012) en berenjena y Soleymani (2017) en cártamo e igualmente a su constitución genética como fue reportado por Sun et al (2014) en maní y Szemruch et al (2015) en girasol, quienes manifestaron que la germinación, vigor al igual que la velocidad de crecimiento de las plántulas está en función de la cantidad de ácidos grasos. En lo pertinente a la cantidad de semillas se registró diferencias altamente significativas, ya que con 100 semillas se presentó un mayor valor de la conductividad eléctrica.…”