Upgradation of Onion Seed Planting Value using Floatation Technique

Abstract

An investigation made with onion to upgrade the quality of seeds based on specific gravity using floatation technique with water and salt solutions (0.5, 1.0 and 2.0%) and studies on anatomical structures for the separated fraction of sinkers and floaters of floatation graded seeds were carried out with the use of SEM (Scanning Electron Microscope). Results revealed that the suitability of water and 2.0 % salt solution for separating the seeds as floaters and sinkers. Higher seed recovery was obtained by water (96.8%) whereas 2.0 % salt solution resulted better with respect to other seed quality characters. The sinkers of 2.0 % salt solution recorded maximum 100 seed weight (0.36 g), speed of germination (8.3), germination (94%), shoot length (8.1 cm), root length (5.9 cm), dry matter production (22.3 mg 10 seedlings-1) and vigour index (1316). In anatomical study, presence of curved embryo in the sinkers was clearly observed, whereas in the floaters the embryo was not observed at all, instead a well distinct empty cavity was noticed. However, the presence of endosperm was recorded in the floaters of onion seeds. Thus, the floatation technique could be used to improve the plating value in Onion.