Structural differences of the stigmatic papillae in distylous Linum hirsutum and monostylous Linum tenuifolium

Abstract

The stigmatic receptive surface of distylous Linum hirsutum and monostylous L. tenuifolium were investigated by using a light and a scanning microscope and cytochemical differences were identified. The papillate stigma is linear in both morphs of L. hirsutum and is capitate in L. tenuifolium. The stigma surface of the pin (long-styled) and thrum (short-styled) morphs in L. hirsutum demonstrates distinct differences. In the thrum morph, a cap like zone consisting of a pectic substance is present between the cellulose-pectin layer and the cuticle at the apical region but the papillae in the pin morph lack a cap zone. In the thrum morph, the cuticle seems to be discontinuous at some regions and is disrupted with thinner patches. In the pin morph the cuticle is continuous at the surface of papillae. The stigma of the pin morph is of the dry type, the thrum stigma of the wet type. In the homomorphic L. tenuifolium lack a cap zone, the cuticle is continuous. Therefore, it seems to be the dry type of stigma. © 2007 Akadémiai Kiadó.