Examining the Gametophytic Calyptra and its Role in Sporophyte Development of the Moss Funaria hygrometrica Hedw.

摘要

My dissertation focuses on hypothesis that the gametophytic calyptra is covered by a cuticle and functions to prevent desiccation of the moss sporophyte apex. The following novel observations were made using the moss Funaria hygrometrica Hedw during the course of my dissertation research. The calyptra has a cuticle that is multi-layered and thicker than the cuticle on either the leafy gametophyte or sporophyte (Chapter 1; Budke et al., 2011). The calyptra cuticle develops precociously, establishing the anatomical potential for desiccation protection early relative to sporophyte cuticle development (Chapter 2). Experimental removal of the calyptra cuticle negatively affects sporophyte reproductive fitness (Chapter 3). Additionally, I have undertaken a review of the scientific literature revolving around the function of the moss calyptra. This review synthesizes French, German, Swedish, Latin, and English literature from the late 1700s to the present (Chapter 4).;My findings support the hypothesis that the calyptra and its cuticle play an influential functional role in desiccation protection during moss sporophyte development. More broadly, my research adds to the body of literature supporting the idea that the plant cuticle is an important functional innovation for desiccation protection and for the evolution of embryophytes on land.