TEMPERATURE AND SUBSTRATE INFLUENCES ON SEED GERMINATION AND SEEDLING FORMATION IN Callisthene fasciculata Mart. (VOCHYSIACEAE) IN THE LABORATORY1

Abstract

-Callisthene fasciculata Mart. is a tree belonging to the Vochysiaceae family. Its wood is moderately heavy and resistant and used to make poles, beams, and other structures. The aim of this work was to evaluate seed germination and the initial growth of seedlings of C. fasciculata at different temperatures and in different substrates. Seeds were collected from fruits in the Pantanal de Miranda, Mato Grosso do Sul state, Brazil. In one experiment, the seeds were subjected to constant temperatures of 20, 25, 30 and 35 °C and to alternating temperatures of 20-30 and 25-35 °C (on paper substrate). In another experiment, the seeds were subjected to temperatures of 20 and 25 °C on three substrates (sand, vermiculite and between paper) in a germinator. The experiment had a randomized design, with four replicates of 25 seeds per treatment. The F-values obtained for germination indicated no significant effect of substrate or temperature on the final germination percentage. The analyses revealed no effect of a treatment interaction (temperature x substrate) on either germination or average germination time; however, a treatment interaction effect was observed on the germination speed index. The treatment combinations yielding the best performance were between paper substrate at 20 °C and sand substrate at 25 °C. There was a significant effect of the interaction between temperature and substrate on seedling growth, with increased root growth observed in the between paper substrate at 25 °C and increased aerial component growth in both sand at 20 °C and vermiculite at 25 °C. The between paper treatment at 25 °C yielded the greatest final seedling size. Between paper is the most recommended substrate for the production of seedlings due to its ease of handling and lower probability of contamination.

Effect of Different Temperatures on the Germination of Callisthene major (Vochysiaceae)

“…This situation may be related to slower respiratory rates or increased stiffness of the cell membrane (Bewley et al, 2013;Bradford & Nonogaki, 2007). On the other hand, in showing germination results for C. fasciculate, Oliveira et al (2015) indicated that the temperature of 20 °C did not negatively interfere with the beginning of the germination process (root emission), demonstrating differences in adaptation to the environment.…”

“…The formation of normal seedlings occurred at all temperatures with values above 90%, indicating that the 3 -7 tested conditions did not negatively interfere with the initial formation of the evaluated structures. In evaluating the formation of Callisthene fasciculata seedlings, Oliveira et al (2015) also described that the presence of abnormal seedlings was not noticed under the tested conditions.…”

“…The water content in the seeds was 11.2%, lower than that obtained for other species of the same genus (Callisthene fasciculata Mart.) collected in the Pantanal, which presented values between 24.9% and 26.8% (Oliveira et al, 2015). Other species of the family have values between 9.4% (Vochysia rufa Mart.)…”

“…According to Baskin & Baskin (1998) and Fenner & Thompson (2005), the germination behavior of a species is related to habitat, seed size and life cycle, while Bewley et al (2013) describe that a small average germination time may be related to rapid colonization of the environment. On the other hand, Oliveira et al (2015) indicated that C. fasciculata, another species of the same genus, needs a slightly longer period to finish its germination process (17 days), with it starting on the third day under the best conditions (20 °C, paper). However, C. fasciculata seeds were collected in Pantanal, which is a floodplain with a different climatic regime from the environment occupied by Callisthene major.…”

GERMINATION AND INITIAL GROWTH OF Sesbania punicea (Cav.)Benth.: INFLUENCE OF SALINITY, FLOODING AND LIGHT1

“…The germination process is a critical stage for plant establishment, where reactivation of metabolic activity with increased vacuolization and reserve mobilization of endosperm cell are the first signs that a seed has transitioned to germination (Penfield, 2017). The sequence of physiological and biochemical events during the germination of seeds is influenced by several abiotic factors, such as light, temperature and hydric saturation of the soils which can restrain or inhibit germination (Oliveira et al, 2015;Oliveira and Gualtieri, 2016).…”