Morpho-anatomical, physiological and biochemical changes in rubber tree seeds

Abstract

The physical, physiological and biochemical changes during the development until the dispersal of rubber tree seeds were evaluated with the purpose of estimating the point at physiological maturity. A total of 30 plants were selected at different points in a commercial planting area and had their flowers marked during the anthesis and every 15 days after marking. Fruits and seeds were collected for analysis of moisture content, dry matter, diameter and length. Details of the anatomy ultra-structure of the seeds were evaluated. The seed emergence, emergency speed index, heat resistant proteins and oxidative stress enzymes were examined. It was observed that fruits reached maximum size at 120 days after anthesis and seeds at 150 days. The seeds acquired germination capacity after 150 days. At 175 days, they presented the highest percentage of dry matter and lowest moisture, in addition to a higher percentage of germination and vigor. Therefore, it was possible to conclude that the physiological maturity of the rubber tree seeds occurs at 175 days after anthesis, and coincides with its maximum physiological quality. At 175 and 180 days post-anthesis, there is a greater expression of heat resistant proteins as well as low molecular weight and greater oxidative stress enzyme activity.

Histochemical approach of the mobilization of reserve compounds in germinating coffee seeds

“…While superoxide dismutase (SOD) acts by normalizing reactive oxygen species (ROS), which are generally harmful for cellular metabolism, mainly during seeds germination. Increased enzyme activity was observed in seeds and related to preparatory events for germination (Souza et al, 2018).…”

“…The presence and proportion of each of these components are directly related to the production of more vigorous coffee seeds. Germination is a biochemical and physiological process that begins with water uptake by the seed and the activation of metabolism (Reis;Souza;Brito, 2020), as well as endosperm weakening which accompany further embryo development (Walters;.…”

Germination and in vitro development of mature zygotic embryos and protein profile of seedlings of wild and cultivated Hevea brasiliensis

“…Although rubber trees are perennial plants with a long cycle of conventional reproduction (Tan et al 2019), they are traditionally propagated by grafting clones from aboveground organs and rootstock derived from illegitimate seeds. These seeds have recalcitrant characteristics, and easily lose viability and germinative power (Bonome et al 2011, Theodoro & Batista 2014, Souza et al 2018). In addition to the diffi culties related to the recalcitrancy of seeds, this is a longterm process since clones require one to two years before plants can be transplanted into the fi eld (Mendanha et al 1998, Alvarenga & Carmo 2014, Martin et al 2018.…”