Kozakowalski et al. 2021 (Article) Germination

Morphology and anatomy of seedlings of Bromeliaceae from the perspective of ecophysiological types

Author(s):—V. Kozakowalski, R. Capuanotardivo, F.M.C. Oliveira & K.S.M. Mourão

Publication:—Flora 2021: 1-44 (online pre-proof). (2021) — DOI

Abstract:—Bromeliaceae is composed of almost exclusively neotropical plants whose species have terrestrial, epiphytic/rupicolous, or atmospheric habitats. The family is divided into five ecophysiological types, considering the diversity of habitats, morphology, and the absorptive capacity of roots. In this study, our goal is to provide information on the average time and type of germination, the morphology, and the anatomy of seedlings of twelve species of Bromeliaceae during their development, relating these data to the ecophysiological type of each species. For this purpose, seeds of twelve species were germinated, and the development of their seedlings was followed through periodic sampling until the formation of the third eophyll. We described the morphology and anatomy of the different sampled stages. Our data show that species of ecophysiological types I-III (Pitcairnioideae and Bromelioideae) are more dependent on soil from the moment of germination until the establishment of the seedling. This is notable in germination, which begins with the protrusion of the radicle, rapid growth of the primary root, and late development of peltate trichomes in eophylls. On the other hand, species belonging to ecophysiological types IV and V (Tillandsioideae) are less dependent on soil from their germination, which begins with the emergence of the cotyledonary sheath or phaneromer, until the establishment of the seedling, in which primary roots develop very slowly (they may or may not reach 1mm in length) and peltate trichomes develop early in eophylls. This present work is the first that brings morphological and anatomical data of the seed germination process and the seedlings from an ecophysiological perspective. Also, the data presented here contribute to a better understanding of seedlings’ establishment and further applications on studies with evolutionary and ecological perspectives.

Keywords:—developmentecophysiological typesgerminationglandular trichomespeltate trichomesroot