Do pre-sowing treatments affect seed germination in Albizia richardiana and Lagerstroemia speciosa ?

Abstract

In this paper, seed morphology and effects of pre-sowing treatments were studied. Matured seeds of the species were collected from healthy trees in the National Botanical Garden, Bangladesh, and treated with five pre-sowing treatments. The average length, breadth and thickness were found to be 0.56±0.03 cm, 0.44±0.009 cm and 0.26±0.008 cm in Albizia richardiana King and Prain, and 1.32±0.02 cm, 0.55±0.04 cm and 0.11±0.002 cm in Lagerstroemia speciosa L., respectively. Germination was carried out in polybags with a mixture of topsoil, coconut husk compost, coarse sand and fine sand in a ratio of 3∶4∶1∶1. Results revealed that the germination rates of seeds in different pre-sowing treatments were significantly increased compared to those in cold-water treatment in both species. The highest germination rate was found to be 96% in hot-water treatment followed by 87%, 83% and 49% in treatments with scarification, H₂SO₄ and control in A. richardiana, respectively. However, the highest germination rate (79%) was found in H₂SO₄ treatment followed by 64%, 62% and 25% in treatments with hot water, scarification and control in L. speciosa, respectively. The lowest germination (35% in A. richardiana and 20% in L. speciosa) was found in cold-water treatment in both cases. Analysis of variance (ANOVA) showed the significant difference among the treatments for both species. It is concluded that hot-water treatment is recommended for seed germination of both species in rural Bangladesh.

Key words： seed dormancy; seed-coat; pericarp; Albizia richardiana; Lagerstroemia speciosa