Desiccation tolerance of Tapirira obtusa seeds collected from different environments

Abstract

-This study was aimed at evaluating the desiccation sensitivity in seeds of the tree Tapirira obtusa (Benth.) J. D. Mitchell collected from three different environments and subjected to two distinct drying speeds. Seeds were collected from a rocky area, in the "Cerrado", and in a riparian forest area, in the region of municipality of Lavras, State of Minas Gerais. The seeds were subjected to drying with magnesium chloride (slow drying) or silica gel (fast drying), into closed environment, until moisture contents of 40%, 30%, 20% and 10%, considering as control, the percentage of germination at the initial moisture content in each environment, which varied from 47% to 50%. Percentages of germination and normal seedlings as well as germination speed index were assessed. For the three environments studied, there was no effect of slow drying on seed germination. Seeds from area of Cerrado, however, have shown a slight reduction on germination when subjected to fast drying. Oppositely, seeds from rocky area had germination increased when subjected to fast drying. Seeds from riparian forest area had no reduction on germination percentage, independent of drying speed. Results suggest that seeds of T. obtusa are not sensitive to desiccation.

Drying on the germination and vigor of Crataeva tapia L. seeds

“…J. D. Mitchell seeds submitted to drying, water content reduced quickly from 50 to 10%; however, the moisture loss varied with the place of origin (rocky area, closed area, or riparian area), being that seeds from Cerrado environment lost the water lost slowly and were more sensitive to dehydration (PEREIRA et al, 2012), indicating that depending on the environmental conditions, the seed characteristics can adapt and undergo changes in their responses.…”

Use of different conditioning agents and quality evaluation of two lots of annatto (<i>Bixa orellana</i>) seeds

“…Many authors have attributed the low germination of annatto seeds to seed coat impermeability (CASTELLO et al, 2012;COSTA et al, 2018;PEREIRA et al, 2012;POORNIMA;AMBIKA, 2012). In anatomical analyses of annatto seeds, Amaral et al (2000) observed the formation of structures that hardened the seed coat when seed water content varied between 26.4% and 10.4%, leading to seed impermeability and a decrease in germination (40% and 20%, respectively).…”

“…Annatto seeds had been previously classified as non-tolerant to desiccation (PEREIRA et al,2012;POORNIMA;AMBIKA, 2012) because research had shown that seed toughness manifested after drying them below 10% of water content (AMARAL et al, 2000;POORNIMA;AMBIKA, 2012). However, we are not aware of studies that have evaluated long storage periods for this species.…”

Germinação em temperatura sub-ótima de embriões de Inga vera subsp. affinis obtidos sob diferentes condições ambientais

“…Estudos relatam que diferenças nas características fisiológicas e germinativas em sementes de populações da mesma espécie podem ser resultantes do grau de maturidade ou da qualidade inicial das sementes, condicionadas pelas variáveis meteorológicas do ambiente durante a formação, como a precipitação pluvial e a temperatura do ar (Daws et al 2004(Daws et al , 2006Martins et al 2009;Lamarca et al 2011;Pereira et al 2012;Lamarca et al 2013). Tal fato também pode ter ocorrido para os embriões de Inga vera subsp.…”