Germination of Heteromorphic Seeds ofAtriplex aucheriand its Hormonal Explanation

Abstract

Atriplex aucheri is an annual producing three morphologically distinct types of fruits and seeds on the same plant. The primary aim of this study was to compare germination characteristics of heteromorphic seeds, ascertain their dormancy types and give hormonal explanation. Different types of seeds absorbed water at different rates with brown seeds imbibing water faster. Germination percentages of brown seeds were significantly higher than those of small and large black seeds at all temperature regimes tested. Germination of both types of black seeds was significantly increased by cold stratification. Contents of GA and ABA of brown seeds were significantly higher than that of black seeds; while contents of ZR and IAA of black seeds were significantly higher than that of brown seeds. The difference of endogenous hormones among different seed types can partly explain their dormancy and germination. Brown seeds of A. aucheri are non-dormant, whereas large and small black seeds have non -deep physiological dormancy. In the field cultivation, brown seeds of A. aucheri can be sown directly in spring and the two types of black seeds should be stratified at cold temperature for 8–12 weeks before planted.