Flacourtia indica (Salicaceae) is a multipurpose tree native to tropical regions of Africa and India, where it is mainly used for food and medicines. Its use in reforestation is limited by poor knowledge of its seed biology and germination ecology. The aim of this study was to determine how its morphological and ecological seed traits interact with the environment and affect seed germination and seedling emergence.
The results showed high germination percentages (> 70%) when stones were incubated at alternating temperature regimes, regardless of the photoperiod. Lack of daily temperature fluctuation resulted in low germination, especially when the stones were incubated in the dark (< 12%). Germination in a 12/12 h photoperiod at constant temperature was positively correlated with temperature, although final germination never surpassed 50%. The addition of GA3 to the substrate resulted in high final germination regardless of temperature regime or photoperiod. Stones and seeds imbibition curves suggest a lack of physical dormancy, while the presence of a fully developed spatulated embryo excluded morphological dormancy. High germination at alternating temperatures (> 70%) discarded the presence of deep physiological dormancy (PD), but differences found between chipped and non-chipped seeds suggest the presence of a non-deep PD, imposed by the seed coat.
Thus, difficulties in propagating this species from seeds, which have been previously reported in the literature, are probably due to initial poor seed lot quality rather than dormancy. These results suggest that F. indica seed germination is more likely to occur near the soil surface or when the tree canopy is disrupted, where daily temperature fluctuations are high and light might become available. Viable seeds not meeting germination conditions are likely to become part of the soil seed bank. Our results will help to support the effective use of F. indica seeds in reforestation and livelihoods programmes.
There are 0 files associated with this work.
- Resource type
Royal Botanic Gardens, Kew
- Journal title
South African Journal of Botany
- Official URL