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

Abstract

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 °C. Germination data were analyzed by the previously developed time-germination model p = A{1 − exp[−k(t − t0)]}. Each germination curve had a coefficient of determination (R2) higher than 0.89, except when there was lack of germination. Results show that higher germination was better achieved at lower (10 or 15 °C) rather than at the higher temperatures (20 or 25 °C). When comparing germination results at temperatures of 10 and 15 with results at 20 °C, germination decreased by at least 30% and became near zero at 25 °C in seed stored for 4 months. Similarly when seeds were stored for 16 months, germination decreased by ≈20% at 20 °C, and again was near zero for germination at 25 °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.