AB 11:169-177 (2010)  -  DOI: https://doi.org/10.3354/ab00300

ABSTRACT: Effects of cold-wet stratification periods (0, 5, and 10 wk) and temperature fluctuation at different outdoor burial depths (0, 5, and 10 cm) on seed germination were examined in 14 wetland species from the temperate region of central China, with the aim of improving germination for rehabilitation. Prior to cold-wet stratification, only seeds of 1 species, Eclipta prostrata, germinated to a high percentage (>90%), and a few seeds (<20%) germinated in 10 species. Five wk of stratification significantly promoted germination in 6 species, but only 2 species germinated ≥50%. Ten wk of stratification significantly promoted germination in 11 species, and 6 species germinated ≥50%. In general, seeds of perennials required longer stratification periods than those of annuals to come out of dormancy. Burial significantly enhanced germination percentages in 7 species. Time to 50% of germination (t₅₀) values indicated that 11 species germinated much faster after burial treatments than after stratification treatments. During 1 wk of continuous monitoring, the mean amplitude of daily temperature fluctuations at 0 cm was much higher than that at the other 2 depths. Even though 8 species differed significantly in germination percentages at different burial depths, their optimal germination varied in relation to burial depth. The results suggest that cold-wet stratification for 10 wk or outdoor burial for 5 wk could significantly improve seed germinability of most temperate wetland plants.

KEY WORDS: Amplitude · Seed dormancy · Temperature fluctuation · Rehabilitation