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.

Guilandina bonduc L. is a pantropical coastal shrub with varied fruits and seeds, capable of germinating under saline stress. This study aimed to morphologically characterize the fruits and seeds of the species, correlate these characteristics, and evaluate the tolerance of seedlings to salt according to seed mass. Physical variables (length, width, thickness, and weight) were analyzed, and Spearman’s correlation was applied. Germination was tested with light seeds (<1.55 g) and heavy seeds (≥1.55 g) under five levels of salt stress, in a 2 × 5 factorial design. G. bonduc can produce seeds with variations in mass and size that are not necessarily related to fruit size. The reduction in osmotic potential resulted in lower seed germination and vigor; even so, the species demonstrated tolerance to salt stress, maintaining germination rates above 50% even under conditions of −1.0 MPa, regardless of seed mass. Lighter seeds germinate more quickly and uniformly, while heavier seeds produce more vigorous seedlings, especially in the absence of salinity, and are therefore more suitable for seedling production. These results indicate that G. bonduc has potential for revegetation of saline areas, being useful in adaptation to climate change due to its tolerance to saline stress and the relationship between seed mass and seedling vigor.