Hymenaea martiana is a species native to Brazil. It has ecological value, contributes to forest restoration, and is economically important because of the use of its wood and fruits. However, it is frequently exploited. Therefore, understanding genetic diversity becomes essential for guiding conservation strategies as well as ecological restoration actions in the face of climate change and anthropogenic pressures. Thus, this study aimed to evaluate the intraspecific diversity of 160 H. martiana mother plants on the basis of morphological descriptors of fruits and seeds and physiological indicators of seed quality, identifying the most discriminating characters. Eighteen traits were analyzed and subjected to analysis of variance and the Scott–Knott test (p < 0.05), with estimates of heritability and the ratio between genetic and environmental coefficients of variation. Phenotypic divergence was obtained via the Mahalanobis distance (D²) and grouped via UPGMA, whereas the relative contribution of the traits was estimated via the Singh method. The results revealed that seed length and weight, emergence speed index, and shoot dry mass were the most effective descriptors for discriminating parent plants. Multivariate analysis revealed the formation of eleven phenotypically distinct groups, demonstrating high variability. These findings support the selection of superior genotypes and representative seed collection, as well as practical initiatives such as the formation of germplasm banks, the selection of breeding stock for forest nurseries, and reintroduction programs. Thus, the data obtained offer technical and scientific support for biodiversity conservation and ecosystem recovery in the semiarid region of Brazil.

Forest fires have become more common in all Brazilian ecosystems, including the Caatinga, a seasonally dry tropical forest that is threatened by increasing aridity. The aim of this work was to analyze the effects of thermal shock, which simulates forest fires, on the germination of seeds from two columnar cacti in this ecosystem. To simulate the effects of fire, seeds of Cereus jamacaru and Xiquexique gounellei were subjected to the following heat treatments: 80 °C/5 min, 80 °C/10 min, 100 °C/5 min, 100 °C/10 min; and a control (i.e., no heat). After the treatments, the seeds were allowed to germinate at a constant temperature of 25 °C and evaluated daily for 30 days. The statistical design was entirely randomized following a 2 × 5 factorial arrangement (species × heat shock). The heat treatments influenced all the response variables, reducing the viability and vigor of C. jamacaru and X. gounellei seeds as the heat treatment temperature increased. Compared with the control treatment, heat treatment at 100 °C for 10 min caused decreases of 94 and 56% in the germination of C. jamacaru and X. gounellei seeds, respectively. Compared with C. jamacaru seeds, X. gounellei seeds are more tolerant to heat shock, suggesting a relative ability to develop a soil seed bank that can persist after forest fires in the Caatinga and recolonize disturbed areas; thus, understanding these adaptations provides useful insights into conservation strategies.

The aim of this study was to assess phenotypic variation and its implications for genetic diversity in natural populations of Spondias tuberosa. Fruits were harvested from 38 mother plants from three natural populations, and the physical traits of the fruits, endocarps, and physiological quality of the seeds were evaluated in a completely randomized design with four replicates of 25 fruits per genotype. The data were subjected to analysis of variance, and the means were grouped via the Scott–Knott method. Genetic diversity was evaluated via UPGMA and Tocher clustering methods, which are based on the Mahalanobis distance (D²) and canonical variables, whereas the relative importance of the characters was evaluated via the Singh method. The results indicated high phenotypic variability, with fruit length was the main discriminant trait among genotypes. The groupings formed six (UPGMA) and 12 groups (Tocher), indicating greater divergence within populations. The analysis of phenotypic data provides a solid basis for understanding the ecological dynamics of and supporting sustainable management practices for S. tuberosa, in line with bioeconomic objectives. This study highlights the importance of preserving phenotypic variability in populations, which is essential for the adaptation of species to environmental changes and for improving local bioeconomies.

Species like Crateva tapia, valued for its ecological and nutritional importance, with discontinuous flowering and fruiting, make it challenging to anticipate the harvest time of fruits and determine the physiological maturity of seeds due to the variety of maturation stages on a single plant. Thus, the objective in this study was to determine the physiological maturity of C. tapia seeds. A completely randomized design was used, in a split plot scheme with four replicates. In the plots was evaluated the production cycles 2020-2021 (cycle I) and 2021-2022 (cycle II), and in the split plot was evaluated the maturation stages: 25, 40, 55, 70, 85, 100, 115, 130, 145, 160, and 175 days after anthesis. The evaluated characteristics included the physical (fruit and seeds) and physiological (seeds) traits throughout their development. As the fruits matured, their color changed from deep green to yellow, while the seeds transitioned from pink to dark brown. The seeds reached maximum germination capacity and vigor at 153 and 126 days in cycle I, respectively, and at 149 and 136 days after anthesis in cycle II, respectively. C. tapia seeds reach physiological maturity between 142 and 150 days after anthesis. Morphological aspects of the fruits, such as green coloration with small yellow traces, indicate the physiological maturation of the seeds. The development of C. tapia seeds involves morphological and physiological changes that affect their quality and germination capacity. Climatic conditions (temperature and precipitation) during seed formation influence the germination process and vigor.

Viviparity is rarely reported in species with seed physical dormancy. This is because physical dormancy, common in tropical trees, results from the impermeability of the seed tegument to water and regulates the timing of germination. Records of germination within the fruit in such species suggest greater functional plasticity than traditionally assumed. This study reports and quantifies viviparity in Hymenaea martiana seeds over four consecutive years (2019–2022) and assessed seed dormancy status through vigor tests. Sixty fruits were collected annually, and viviparity was estimated as the proportion of fruits containing at least one seed with radicle protrusion. Non-viviparous seeds were subjected to emergence tests with and without mechanical scarification, and cumulative emergence, percentages of dead and water-impermeable seeds, and seed water content were evaluated. Viviparity occurred consistently, affecting approximately 10–15% of the fruits, with no significant differences between years, indicating that the phenomenon was not associated with extreme environmental events. However, early germination did not result in seedling establishment because the emerging roots dehydrated while still inside the fruit. Mechanical scarification significantly increased emergence, confirming the presence of seed physical dormancy. These results show that, although viviparity was observed recurrently in the studied population of H. martiana, seed physical dormancy remains the main mechanism controlling germination in this species.