Response of spores and young gametophytes of Cyathea delgadii Sternb. (Cyatheaceae) and Blechnum brasiliense Desv. (Blechnaceae) to different light levels

Acta Botanica Brasilica

Rosane Hiendlmeyer¹  Aurea Maria Randi¹ 

[1] ,University of Santa Catarina Department of Botany Florianópolis SC ,Brazil

关键词: ferns;    germination;    light levels;    photoinhibition;    spores;    esporos;    fotoinibição;    germinação;    níveis de luz;    pteridófitas;   

DOI  :  10.1590/S0102-33062007000400015

来源: SciELO

【 摘 要 】

Light is a limiting factor for fern stablishment because it controls germination of light sensitive spores. The aim of this work was to study the effect of light levels on spore germination in two ornamental ferns native to the Atlantic forest, under natural conditions. Cyathea delgadii is a tree fern and Blechnum brasiliense, a subarborescent fern. The effect of light levels was analyzed in April and July/2003, in Florianópolis, Santa Catarina state, Brazil. Sterilized spores were sown in Erlenmeyer flasks containing mineral culture medium with macronutrients, iron, and benomyl 0.01%. The Erlenmeyer flasks were kept in 50 cm³ boxes covered with black shade netting, which gave 5, 22, 42, and 62% natural light. Irradiance and temperature were scored daily at 14:00 h during the study period. Higher percentages of germination were observed at 5 and 22% light for both species. Germination of Cyathea delgadii spores at 22% light reached 76% and mean germination time was 19.7 days; at 5% light, germination reached 83.5% and mean germination time was 20.16 days. Germination of Blechnum brasiliense at 22% light reached 76% and mean germination time was 9.06 days; at 5% light, germination reached 84% and mean germination time was 13.18 days. The highest light levels inhibited spore germination and the gametophytes died during the test period.

【 授权许可】

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