Germination and Vigor of Lettuce Seeds Under Different Temperatures

Abstract

The objective of this study was to evaluate the effect of temperature on germination and vigor of the seeds of different lettuce cultivars. It was used a completely randomized design in a factorial arrangement 4x3, with four cultivars (American, Crespa para Verão, Mimosa Salad Bowl, and Crespa Repolhuda) and four temperatures (20, 25, 30 and 35°C), with four replicates per treatment. The effects of the treatments were evaluated by germination and vigor tests (first count, germination speed index). There was influence of the lettuce grow crops on germination and seed vigor. The cultivars of the lettuce have a higher germination and vigor when exposed to 20°C, and the Crespa for daylight showed itself more tolerant to temperatures of 25 to 30°C. The temperature of 30°C inhibits the germination of lettuce seeds of the Americana, Mimosa Salad bowl and Crespa Repolhuda cultivars

Influence of temperature on the germination and root size of Acmella oleracea (L.) R. K. Jansen

“…According to Carvalho and Nakagawa (2012), this defines the appropriate temperature range for the seed germination test standardization, as well as for seedling production. Similar effects have been recorded for other species; Soares et al (2017), testing the effect of three temperatures (20, 25 and 30 ºC) on seed germination and vigor of lettuce cultivars, observed a reduction in germination percentage in different cultivars at 30 ºC, a temperature that also significantly inhibited germination.…”

“…Segundo Carvalho e Nakagawa (2012), isso define uma faixa de temperatura adequada para padronização do teste de germinação, bem como para produção de mudas. Quanto ao efeito da temperatura para outras culturas, Soares et al (2017), avaliando de três temperaturas (20, 25 e 30 ºC) na germinação e vigor de sementes de cultivares de alface, observaram redução da porcentagem de germinação nas diferentes cultivares, tendo a temperatura de 30 ºC inibido significativamente a germinação.…”

“…Temperature is a significant factor in the germination process, since it regulates the biochemical reactions that trigger it (OLIVEIRA; BARBOSA, 2014). The action of temperature on the germination process has been reported by researchers for a great variety of species of vegetables (AMARO et al, 2014;CATÃO et al, 2014;NASCIMENTO et al,2016;SOARES et al, 2017). In lettuce seeds, for example, temperatures above 25 °C are known to cause decrease in physiological potential, reducing germination, germination speed, and water absorption, as well as biochemical reactions central to the successful germination of this species CANTLIFFE, 2002;ZUFFO et al, 2017).…”

“…A temperatura constitui um fator de expressiva importância para o processo germinativo, visto que regula as reações bioquímicas que o desencadeia (OLIVEIRA; BARBOSA, 2014). A ação da temperatura sobre o processo germinativo tem sido reportada por pesquisadores em diferentes espécies de hortaliças (AMARO et al, 2014;CATÃO et al, 2014;NASCIMENTO et al, 2016;SOARES et al, 2017). Em sementes de alface, observa-se que temperaturas acima de 25 °C causam diminuição do potencial fisiológico, reduzindo a germinação, a velocidade de germinação, a absorção de água, bem como reações bioquímicas chaves ao processo germinativo dessa espécie CANTLIFFE, 2002;ZUFFO et al, 2017).…”

Enviromental temperature and age of seeds in tolerance to thermoinhibition in lettuce genotypes1

“…The mechanisms involved in germination at high temperatures are also related to the vigor of lettuce seeds, both in thermosensitive and in thermotolerant cultivars (Soares et al, 2017). As already mentioned, the shorter storage periods, less than 100 DAH, had a lower germination and vigor for all cultivars under temperatures higher than 30 ºC.…”