Seed germination and seedling establishment of Securidaca longepedunculata (Polygalaceae)

Securidaca longepedunculata fresen. (polygalaceae) is a multipurpose tree valued for its medicinal uses in limpopo province,south africa. hence,it is threatened due to human pressure which affects its regeneration potential since it is uncultivated. this poses a challenge in efforts aimed at its conservation. the objective of the present study was to investigate the germination potential of securidaca longepedunculata seeds which have a very low and erratic germination under natural conditions. seeds were collected in nylsvley nature reserve and a number of pre-treatments,namely seed coat removal,sulfuric acid,gibberellic acid,boiled water,cold water and control were tested for their efficiency to improve germination under field,laboratory and greenhouse conditions. the results showed that some of pre-treatments have a stimulating effects on seed germination and seedling growth. removal of the seed coat resulted in the highest germination percentage. this pre-treatment gave 90% seed germination under greenhouse conditions,while it was 63.3% for those grown in the laboratory,whereas untreated seeds under field conditions showed 0% germination. boiled and cold water pre-treatments did not improve seed germination. the average heights of seedlings from different pre-treatments ranged from 4.5 cm to 22 cm with the highest seedling (22 cm) obtained in seed pre-treated with 400mg/l of gibberellic acid. it is concluded that removal of the seed coat is the most effective pre-treatment. © 2017,pakistan botanical society. all rights reserved.