Abstract

ACOSTA, M. Cecilia; ALCARAZ, M. Luciana; CAUSIN, H. Fabio  and  MANFREDA, Vilma T.. Contributions to the morphological and physiological knowledge of reproduction by seeds of Zephyranthes tubispatha (Amaryllidaceae). Bol. Soc. Argent. Bot. [online]. 2023, vol.58, n.3, pp.7-7. ISSN 1851-2372.  http://dx.doi.org/10.31055/1851.2372.v58.n3.40185.

Background and aims: Zephyranthes tubispatha is a South American species with ornamental and pharmacological potential. We aimed to study: 1) attributes of fruits, seeds, seed-seedling transition substages, normal and abnormal seedlings; 2) germination due to the effect of different storage periods, seeding times, and exposure to supra-optimal temperatures; and 3) plant vigor.

M&M: Samples harvested between 2018 and 2022 (Buenos Aires, Argentina) were used. Fruits and seeds were characterized morphometrically and seminal reserves histochemically. Substages during the seed-seedling transition were defined, and normal and abnormal seedlings were morphologically described. The germination of seeds from different storage periods, seeding times, and thermal conditions was evaluated. Changes in seed viability, electrolyte loss, and plant vigor were studied.

Results: In the seeds, lipids and proteins were detected as reserves. Normal and abnormal seedlings and the seed-seedling transition with five substages were described. Seeds of up to 10 months of storage, different seeding times and thermal conditions presented high germination percentages. High temperatures thermoinhibited germination, but did not affect subsequent plant survival.

Conclusions: Storage for more than one year showed increased seed mortality and seedling anomalies. The seeding moment conditioned the germination response to the heat treatments, and thermoinhibition did not affect the vigor of the plants produced.

Keywords : Germination; seeding; seedlings; substages; storage; thermoinhibition; vigor.

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