Physiological quality of lettuce seeds under different temperatures, in presence and ausence of light

Ciência Rural

Nunes, Einar Pasqualli¹  Menezes, Nilson Lemos de¹  Santos, Osmar Souza dos¹  Schmidt, Denise¹ 

[1] Universidade Federal de Santa Maria

关键词: i>Lactuca sativa;    light;    temperature;    germination;   

DOI  :  10.1590/S0103-84782000000600003

学科分类：农业科学（综合）

来源: Universidade Federal de Santa Maria * Centro de Ciencias Rurais

【 摘 要 】

The experiment on the different types of lettuce seeds, and the effects of light and temperature occured in the Didactic Laboratory of Researches in Seeds, of Santa Maria Federal University, Brazil. Elisa, Regina and Rainha de Maio, were selected and tested under the tempreatures of 20°C; 25°C; 30°C; 35°C; 20-30°C, for establish a bifactorial experiment separately conducted, with and without light. The substratum was used on paper in gerbox, with four repetitions of 100 seeds for treatment. The selected light conditions were 8 hours of light and 16 hours of darkness, for every day. For the condition without light an aluminum paper was placed over the gerboxes. The evaluations of plant size and first germination were made in the fourth day and the final percentage of germination, in the seventh day. It was observed that without light, the lower the temperature the more plants germanated. When tested with light it was found that with Elisa and Regina, the tempurature had no effect except at 35º, in which germination was impeded. In conclusion, exist influence of lettuce genotypes in physiological quality seeds. The light is a limiter factor in germination. Within the tested temperatures, it was found that 20ºC was the best for the three cultivars. In presence of light, the plants initial development occured within a wide strip of temperature (20°C to 30°C). Temperature of 35°C cause secondary dormancy in lettuce seeds.

【 授权许可】

CC BY-NC