masterThesis
Partição de carboidratos não estruturais em Erythrina velutina Willd. durante a germinação da semente e estabelecimento da plântula
Fecha
2021-02-26Registro en:
NASCIMENTO, Edson Bruno do. Partição de carboidratos não estruturais em Erythrina velutina Willd. durante a germinação da semente e estabelecimento da plântula. 2021. 45f. Dissertação (Mestrado em Ciências Florestais) - Escola Agrícola de Jundiaí, Universidade Federal do Rio Grande do Norte, Natal, 2021.
Autor
Nascimento, Edson Bruno do
Resumen
Seed germination and seedling establishment are critical processes for plant communities, as
high mortality takes place at these initial steps of the plant life cycle due to the exposure to
biotic and abiotic stresses. Taking into account the central role of carbon metabolism in the
heterotrophy-autotrophy transition, closely related to survivorship, this work aims to investigate
the partitioning of non-structural carbohydrates in the different organs of Erythrina velutina
Willd., a pioneer species from the Caatinga in ecological succession, during seed germination
and seedling establishment. Seeds from ten mother trees were scarified, disinfected, soaked
in distilled water, sown in rolls of Germitest® paper and kept under controlled conditions for 9
days. Then, the seedlings were transferred to hydroponics in distilled water and grown in a
greenhouse for 12 days. The collections were carried out at discrete physiological stages,
including imbibed seed, radicle protrusion, hypocotyl emergence, plumular hook opening, and
emergence of cordiform leaves, first trifoliolate leaf and second trifoliolate leaf. The seedlings
were divided into cotyledons and other parts, according to their appearance during the different
stages. In the course of seedling establishment, the dry weight content progressively
decreased in the cotyledons and transferred to the sink organs, especially to the shoot
according to a decrease in the root/shoot ratio during the experiment. Total soluble sugars,
non-reducing sugars and starch were accumulated in the root and hypocotyl during the initial
stages and the content of these compounds increased in the leaves at the late stages of
establishment. Amylase activity was higher in the shoot than in the root in the course of the
experiment. These results show that E. velutina massively utilized non-structural
carbohydrates to axis growth at early establishment and these compounds may have been
accumulated in the leaves at late establishment as a result of photosynthetic activity.