Seed dormancy overcoming and seed coat structure change in Leucaena leucocephala and Acacia nilotica

Abstract

Leucaena leucocephala and Acacia nilotica are two arboreal legumes with several uses in agriculture, nutritious forage and livelihoods, fence posts, wood production, biofuel production, charcoal, firewood, shading, hedges, windbreaks, and improvement of soil fertility. The seed dormancy is common in Leucaena and Acacia species, and it creates difficulties in seed testing and planting. The aim of this study is to determine the effective methods of sulfuric acid and hot water due to overcoming dormancy in seeds of those species. Most pretreatments significantly (p < 0.05) reduced hard seed content and enhanced germination percentage when compared to nontreated seeds. Effectiveness of water and acid pretreatments increased when increasing in duration time from 3 to 60 min. The best recommended time pretreatment of sulfuric acid 60 min for A. nilotica, and 3 min of hot water for Leucaena. These treatments all reduced hard seeds to 0% and did not cause damage to the seeds during the germination. Further, the lens and hilum both were identified as primary sites for water uptake into the seeds of Leucaena. Whereas, the lens was recognized as the original site of water intake in A. nilotica. In addition, the seed coat anatomy identified that the palisade epidermal layer was dense, and thickness tissue had been prevented imbibition of water in Leucaena and A. nilotica.

Keywords

• leucaena
• acacia
• sulfuric acid
• water intake
• lens
• germination
• seed coat
• anatomy
• dormancy