Temperature Effect on Seed Germination in the Genus Leucocoryne (Amaryllidaceae)

Leucocoryne is a Chilean endemic genus from the Amaryllidaceae family. It is an emerging crop with some registered varieties, currently oriented to a niche ornamental market. In the present work, seed germination in Leucocoryne dimorphopetala, Leucocoryne coquimbensis, Leucocoryne purpurea, Leucocoryne aff. vittata, Leucocoryne aff. violacescens, and Leucocoryne ixioides for seeds stored for 4 months and in L. purpurea, Leucocoryne vittata, L. aff. vittata, and L. ixioides for seeds stored for up to 16 months was analyzed at 10, 15, 20, or 25 degrees C. Germination data were analyzed by the previously developed time-germination model p = A{1 - exp[- k(t - to)]}. Each germination curve had a coefficient of determination (R-2) higher than 0.89, except when there was lack of germination. Results show that higher germination was better achieved at lower (10 or 15 degrees C) rather than at the higher temperatures (20 or 25 degrees C). When comparing germination results at temperatures of 10 and 15 with results at 20 degrees C, germination decreased by at least 30% and became near zero at 25 degrees C in seed stored for 4 months. Similarly when seeds were stored for 16 months, germination decreased by approximate to 20% at 20 degrees C, and again was near zero for germination at 25 degrees C. These germination habits of Leucocoryne are interpreted as an adaptive strategy to its natural habitats. In addition, L. dimorphopetala presents a type of dormancy and other species (L. purpurea, L. ixioides, and L. aff. vittata) may be sensitive to after-ripening changes during storage.