We investigate and characterize the morphophysiological changes related to germination and the initial growth and development of seedlings of wild and cultivated genotypes of the genus Hevea spp. in finding to add value to new clones. Seeds from six genotypes (H. brasiliensis (Willd. Ex A. Juss) Müll. Arg, H. guianensis Aubl., H. spruceana (Benth.) Müll. Arg., RRIM 600, Fx 3844, and IAN 873) were sterilized, and their imbibition curve, germination parameters, and initial seedling growth were characterized. In parallel, the morphology of the germination and post-germination stages was monitored from seeds germinated in washed sand. Morphological differences in the seeds/embryos, different strategies in the imbibition process, emergence, and initial seedling growth were observed. The species H. guianensis and H. spruceana showed the greatest differences in size, shape, and color of the seeds/embryos and initial seedling growth. The characteristics of the seed coat patterns, the seedling imbibition, growth, and development processes can serve as morphophysiological markers for genotype identification and selection. This is the first morphophysiological study of seeds and seedlings of wild and cultivated genotypes of species of the genus Hevea. We conclude that there is considerable phenotypic variability among species of the Hevea genus regarding seed and seedling morphophysiology, which can be explored in the rubber tree breeding programs.

Given the reduced resilience of the Amazon rainforest due to deforestation, identifying high-quality genetic markers for the propagation of native species is crucial for forest regeneration. This study investigated metabolic dynamics during Brazil nut (Bertholletia excelsa) germination to identify biochemical markers for selecting superior genotypes. We analyzed primary reserves (carbohydrates, lipids, proteins) and minerals in two genotypes, 606 and Santa Fé, in seven germination stages. Our results revealed distinct metabolic patterns. Genotype 606 showed 101.73% greater efficiency in the transient accumulation of starch, 34.86% higher degradation of lipids, and 34.86% higher transitory synthesis of soluble proteins. Conversely, Santa Fé was 16.8% more efficient in amino acid synthesis and 795.33% in boron compartmentalization, though less so in sucrose (2.17%) and in lipid synthesis (24.84%). Overall, early germination stages involved starch, sucrose degradation and mineral consumption. During post-germinative stages, protein and lipid degradation likely fueled gluconeogenic pathways and supported carbohydrate synthesis and seedling growth. This work increases the knowledge on Brazil nut germination physiology and identifies metabolic markers that differentiate genotypes. These findings are fundamental for our understanding of primary metabolism turnover in B. excelsa and provide a basis to support forest restoration and genetic improvement programs. In addition, we hope to contribute to the selection of superior high-performance genotypes, which are essential for recovering degraded areas and enhancing productive plantations in the Amazon region.

Anais do Simpósio Estadual de Produtos Naturais (978-65-5941-203-7) - Caracterização De Inibidores De Proteases De Sementes De Diferentes Genótipos De Hevea Spp.