Ingrid Pinheiro Machado

Intraindividual variation in floral traits is central to plant reproductive dynamics, yet within-crown patterns in tropical andromonoecious trees remain underexplored. We used dwarf cashew (Anacardium occidentale L.) as a model to test three predictions: (i) floral output and sex ratio differ among crown quadrants due to microenvironmental gradients; (ii) male and hermaphroditic flowers show divergent phenological dynamics; and (iii) flowering abundance does not necessarily predict fruit set. We monitored 120 panicles per bloom across two flowering flushes in two years. Flowering intensity clustered early within the reproductive cycle and varied little between years, indicating stronger effects of within-flush timing than of broad seasonal context. Emission patterns of male and hermaphroditic flowers diverged, with male flowers requiring longer to reach anthesis. The north quadrant exhibited more hermaphroditic flowers, consistent with greater solar exposure, whereas fruit production peaked in the east and west quadrants, revealing a spatial decoupling between flowering and fruiting. We also observed protandrous dichogamy. These results show that within-crown microclimate and architectural position structure intraindividual floral variation and that post-floral filters help determine fruit set. Consequently, flowering alone is a poor proxy for reproductive success, underscoring the need to integrate positional, temporal, and post-floral processes when evaluating reproductive performance.

Using reaction norm components instead of traditional phenotypic data in genetic association studies (GWAS) may allow the identification of genomic regions that are more influenced by environmental variables in terms of tolerance and responsiveness to water stress. To test this hypothesis, we used a public genetic diversity panel of tropical maize inbred lines, evaluated in eight environments, four in well‐watered (WW) and four in water stress (WS) conditions. Most SNPs explained at least 40% of the genetic variability, and some reached 67%. The identified genes and genomic regions revealed physiological responses and direct or indirect molecular mechanisms related to water deficit tolerance and responsiveness. This information will enable more assertive selections and subsidize breeding programs aimed at obtaining cultivars for water deficit conditions while reducing the costs of the evaluation processes of reaction standards.

The advances in genomics in recent years have increased the accuracy and efficiency of breeding programs for many crops. Nevertheless, the adoption of genomic enhancement for several other crops essential in developing countries is still limited, especially for those that do not have a reference genome. These crops are more often called orphans. This is the first report to show how the results provided by different platforms, including the use of a simulated genome, called the mock genome, can generate in population structure and genetic diversity studies, especially when the intention is to use this information to support the formation of heterotic groups, choice of testers, and genomic prediction of single crosses. For that, we used a method to assemble a reference genome to perform the single-nucleotide polymorphism (SNP) calling without needing an external genome. Thus, we compared the analysis results using the mock genome with the standard approaches (array and genotyping-by-sequencing (GBS)). The results showed that the GBS-Mock presented similar results to the standard methods of genetic diversity studies, division of heterotic groups, the definition of testers, and genomic prediction. These results showed that a mock genome constructed from the population’s intrinsic polymorphisms to perform the SNP calling is an effective alternative for conducting genomic studies of this nature in orphan crops, especially those that do not have a reference genome.

Flower emission pattern in the dwarf cashew tree (Anacardium occidentaleL.) is essential for understanding the possible differences in the number, distribution over time, and/or proportion of the types of flowers affecting the reproductive dynamics of the species during the flowering. Our study aimed to explain the flowering pattern of the dwarf cashew tree, especially the emission and development of the male and hermaphrodite flowers and the influence of the flower distribution in the canopy for fruit production. Therefore, the canopy quadrants (north, south, east, and west) in two flowering seasons and two years (2018 and 2019) were considered. In each bloom, 120 panicles (one per quadrant of each plant) were randomly selected and monitored, in a randomized block design with 10 genotypes and three blocks, where each plant represented a repetition. There were significant differences in the effects of crop and canopy positions on the dwarf cashew tree. The dwarf cashew tree showed similar fluctuations in the average and cumulative number of flowers over time, regardless of flower type, but with a different pattern in the emission of male and hermaphrodite flowers. Male flowers required more time for anthesis during the harvests. Also, the northern quadrant of the crown had a greater quantity of flowers hermaphrodites, possibly due to a higher incidence of radiation because of the predominant path of the sun in the region. However, fruit production in the quadrants showed greater trends in the east and west quadrants, indicating that the flowering and fruiting patterns diverged.

Introduction: Morphological parameters of flowering are fundamental in the reproductive process of plants, but this subject is poorly explored in the cashew tree Anacardium occidentale. Objective: To determine the influence of the flowering and harvest period on floral parameters, and to identify association with hermaphrodite flowers in the dwarf cashew. Methods: For the 2018 and 2019 harvests in 120 samples we measured number of male/hermaphrodite/abnormal flowers; panicle biomass, length, maximum width, and ramifications at 30, 45 and 60 days for 360 samples in total, for each season (2018 and 2019). Results: The harvest effect was not significant. Panicle length and width (at 30 days), had the greatest contributions to the production of hermaphrodite flowers. The presence of male flowers (at 45 days), and the panicle length and number of primary branches (at 60 days) were the main factors at their respective periods. Conclusions: The emission of hermaphrodite flowers responds negatively to male flowers. Variations in flowering compromise the production of hermaphrodite flowers and the flowering structure. Introducción: Parámetros morfológicos de la floración son fundamentales en el proceso reproductivo de las plantas, sin embargo, el tema es poco explorado en el árbol de marañón Anacardium occidentale. Objetivo: Determinar la influencia de la floración y periodos de cosecha sobre parámetros florales, e identificar asociaciones con flores hermafroditas en el marañón enano. Métodos: Para las cosechas de 2018 y 2019 en 120 muestras, medimos el número de flores masculinas/hermafroditas/anormales; biomasa de panícula, largo, ancho máximo, y ramificaciones a los 30, 45 y 60 días, un total de 360 muestras en cada temporada (2018 y 2019). Resultados: El efecto de la cosecha fue insignificante. Longitud y ancho de la panícula (a los 30 días), tuvo la mayor contribución a la producción de flores hermafroditas. La presencia de flores masculinas (a los 45 días), y el largo de panícula y número de ramas primarias (a los 60 días) fueron los principales factores en sus periodos respectivos. Conclusiones: La emisión de flores hermafroditas responde negativamente a flores masculinas. Variaciones en la floración afecta la producción de flores hermafroditas y estructura de floración.

The advances in genomics in recent years have increased the accuracy and efficiency of breeding programs for many crops. Nevertheless, the adoption of genomic enhancement for several other crops essential in developing countries is still limited, especially for those that do not have a reference genome. These crops are more often called orphans. This is the first report to show how the results provided by different platforms, including the use of a simulated genome called the mock genome, can generate in population structure and genetic diversity studies, especially when the intention is to use this information to support the formation of heterotic groups, choice of testers and genomic prediction of single-crosses. For that, we used a method to assemble a reference genome to perform the SNP calling without needing an external genome. Thus, we compared the analysis results using the mock genome with the standard approaches (Array and GBS). The results showed that the GBS-Mock presented similar results to the standard methods of genetic diversity studies, division of heterotic groups, the definition of testers, and genomic prediction. These results showed that a mock genome constructed from the population's intrinsic polymorphisms to perform the SNP calling is an effective alternative for conducting genomic studies of this nature in orphan crops, especially those that do not have a reference genome.