Atividade respiratória como teste de vigor em sementes de algodão

Abstract

RESUMOVários testes de vigor são utilizados atualmente pelas empresas produtoras de sementes para avaliar a qualidade dos lotes. Entretanto, nem sempre esses testes se relacionam com a emergência de plântulas no campo e possuem desvantagens, como a demora na obtenção de resultados. O trabalho teve o objetivo de avaliar a eficiência da atividade respiratória como teste de vigor em sementes de algodão. Os experimentos foram conduzidos no ano de 2012, em laboratório e em casa de vegetação. Foram utilizadas sementes da cultivar BRS 286. De um lote principal foram obtidos três lotes por meio de envelhecimento acelerado por zero, 48 e 96 h. Além da atividade respiratória foram realizados, também, testes de germinação, emergência em areia, índice de velocidade de emergência, comprimento da parte aérea e raiz, massa da matéria seca da parte aérea e de raiz e condutividade elétrica. A atividade respiratória diferenciou os três lotes em termos de vigor e apresentou correlação positiva com os testes de comprimento de parte aérea e comprimento de raiz. A avaliação da atividade respiratória é eficiente como teste de vigor em sementes de algodão. Palavras-chave: controle de qualidade, Gossypium hirsutum L., qualidade fisiológica, teste de Pettenkofer Respiratory activity as a vigor test for cotton seed ABSTRACTA high number of vigor tests are currently used by seed companies to evaluate the quality of seed lots. However, some of them do not always correlate with seedling performance in the field and in addition there is the disadvantage of long time interval to obtain the results. This study aimed to evaluate the efficiency of respiratory activity as a vigor test in cotton seeds. The experiments were conducted in 2012 in the laboratory and in a greenhouse. The seed of the cultivar BRS 286 was used. From the principal seed lot, three seed lots were obtained by accelerated aging for periods of zero, 48 and 96 hours. Besides the determination of respiratory activity, seed germination, seedling emergence in sand, emergence speed index, shoot and root length, dry mass of shoots and roots and electrical conductivity tests were performed. The respiratory activity classified the seed lots into three vigor levels, and was positively correlated with shoot and root length. The assessment of respiratory activity is effective as a vigor test for cotton seed.

Respiratory activity in wheat seeds as related to physiological quality

“…Overall, the respiratory activity test was correlated with the physiological quality of seeds, and therefore, could potentially be used to quickly estimate the quality, consistent with results found for cotton seeds (VENSKE et al, 2014), soybean seeds (MENDES et al, 2009) and sunflower seeds (DODE et al, 2012).…”

“…On the other hand, the length of the root had a lower correlation (r = -0.59). Dode et al (2013) and Marini et al (2013) also showed a negative correlation between respiration and vigor for sunflower and rice seeds, respectively, which can be explained by the fact that seeds in an advanced process of decay have a higher metabolism, possibly seeking to reorganize its cellular machinery in order to increase respiratory activity (VENSKE et al, 2014). In watermelon seeds, Oliveira et al (2015) found that the respiratory activity allowed the separation of seeds lots, but there were no positive or significant correlations with other vigor tests.…”

“…Quicker evaluation methods would allow seed lots of inadequate quality to be discarded in the seed processing unit, which would consequently saving on costs from unnecessary processing (MARCOS FILHO, 1999). Martins et al (2014) evaluated the separation of seed lots by their respiratory activity and concluded that it was an efficient method for the separation of soy and bean seed lots of different vigor levels. Similar results have also been reported for cotton seeds (VENSKE et al, 2014).…”

“…Martins et al (2014) evaluated the separation of seed lots by their respiratory activity and concluded that it was an efficient method for the separation of soy and bean seed lots of different vigor levels. Similar results have also been reported for cotton seeds (VENSKE et al, 2014). Furthermore, as shown in a study by Marini et al (2013), respiratory activity is indicative of reduced seed quality and can be used to identify factors which are related to seed deterioration.…”

Physiological quality of hybrid maize seeds through respiratory and enzymatic activities

“…Castro (2011) observed this differentiation in maize seeds; Pereira (2012) in pepper and chili seeds; Dranski et al (2013), in canola seeds and Venske et al (2014) in cotton seeds. By the titulation method, it was also possible to separate statically the five lots of maize seeds in three levels of vigor.…”