Effect of the Fruits Type and Conservation Time in the Germination Capacity of Jacaranda (Jacaranda mimosifolia D. DON) Seeds Collected in Alentejo, South Portugal - Abstract
Jacaranda is a deciduous tree from South America, used as an ornamental tree due to its abundant flowering, usually found in South Portugal. The tree
also has forest interest.
Fruits were harvested in 2010, 2013, 2015 and 2017 in the city of Elvas. From the samples collected in 2013 and 2017, two fruit subsamples were obtained: a) dark brown fruits, whose maturation was reached in the previous year and b) light brown fruits, whose maturation was reached in the harvest year. In 2015, 2 subsamples were also collected: a) dark brown fruits and a mixture of all fruits types. The samples were threshed, labeled and conditioned in
a refrigerator (ca. 5ºC). The germination assays were carried out at 20ºC with 12 h of photo phase. Final observations were obtained after 21 days.
The germination results ranged from 11.3% (dark brown, old fruits) to 93.5% (light brown, new fruits). The best results, without significant statistical difference between samples, ranged from 70 to 93.5%, indicating that the seeds of this species harvested in Alentejo (Elvas) have high germination capacity. In the fruit harvesting operations, it is important to separate the fruits, because in the 3 tested samples of seeds harvested in different years, the seeds obtained from light brown, new fruits, had higher germination rates (9 to 35% more), with significant statistical difference from dark brown, old fruits. The seeds harvested in 2010 maintained their germination capacity (71%) when stored in a refrigerator (ca. 5ºC) for 7 years.