Sorghum is one of the most important cereal crop and ranks fifth among cereals after wheat, rice, maize and barley for economic importance. Because the demand of food is increasing, sorghum will increase in importance as a source of food, feed, fibre, and fuel; specially in the European continent where sorghum is little cultivated, mainly due to the lack of sorghum varieties well adapted to the soil and climate conditions such as photoperiod, cold and drought; for this reason, the genetic diversity analysis, through molecular characterization, is an important requirement to begin a plant breeding program. The analysis was performed in 46 sorghum genotypes obtained from the Czech Plant Gene Bank, Crop Research Institute, Prague. Genetic variability values were estimated, through the genetic distance using Dice’s coefficient, and dendrogram constructed using DARwing software. Four out of fifteen of the primers evaluated were completely polymorphic (100%), A hundred and twenty-six scorable bands were identified and 89% of them were polymorphic, the bands ranged from 200 to 2000 bp. The dendrogram grouped the accession into six clusters. The results indicate the existence of high genetic distance values up to 0.8776 among the evaluated accessions, even if the accessions were collected in the same country, or by the contrary, lower genetic diversity among accessions collected in different countries. It may be due to the existence of five ancient races of sorghum, from which were originated most of the wild and cultivated species known nowadays. Mainly, the migration of people from the origin centre of sorghum, located in Ethiopia and Sudan, explain the spread of the genetic material out of Africa. The information generated by this study should be useful for a better understanding of the genetic diversity from the sorghum germplasm stored in the Czech Plant Gene Bank for future plant breeding program.

Guatemala’s wild avocado germplasm holds vital genetic value, but lacking conservation strategies imperils it. Studying its diversity is pivotal for conservation and breeding. The study aimed to comprehensively assess the wild avocado germplasm in Guatemala by combining phenotypic and genotypic data and to create a core collection for conservation and future breeding programs. A total of 189 mature avocado trees were sampled across Guatemala’s northern, southern, and western regions. Morphological characteristics were documented, and genetic diversity was assessed using 12 SSR loci. The investigated germplasm revealed three distinct genetic clusters, exhibiting an average gene diversity of 0.796 and a 7.74% molecular variation among them. The samples showed various morphological characteristics that indicate the presence of three avocado races in Guatemala. The weak correlation between phenotypic and genotypic distances highlighted their independence and complementary nature. The joint matrix effectively integrated and captured genotypic and phenotypic data for comprehensive genetic diversity analysis. A core collection comprising 20% of total accessions that captured maximum genetic diversity was formed. This study exposed wild Guatemalan avocados’ genetic diversity, morphological traits, and conservation significance. Integrated data capture via clustering validates holistic genetic insight for conservation and breeding strategies.

Even though Guatemala is considered one of the three domestication centres of the avocado (Persea americana Mill), little is known about the genetic diversity of its native populations. This is the first study to explore avocado genetic diversity and population structure in native dispersal areas using microsatellite markers. We sampled 189 avocado trees grown from seeds in eight geographical populations, and 12 microsatellite loci were tested for diversity. There were a total of 289 alleles found throughout the 12 loci, with an average of 23.83 alleles per locus. The average observed and expected heterozygosity were 0.53 and 0.83, respectively. The analysis of molecular variance revealed that the eight populations comprised around 2% of the variation. Five of the 28 G'ST(Nei) pairwise comparisons indicated no genetic difference. We discovered a mixture of avocado trees from various populations using unweighted pair group method with arithmetic mean (UPGMA) hierarchical cluster analysis. The sampled individuals were classified into three main genetic clusters by the model-based STRUCTURE and discriminant analysis of principal components (DAPC). The weak genetic structure exhibited by mixing avocado trees from different populations could be mainly attributed to high human-mediated gene flow (Nm = 12.25) due to avocado's importance in food, culture, and Guatemala's religion. The high genetic diversity found in the avocado germplasm suggests that it might be a valuable source of variable alleles that could be used in breeding programs for this crop in Guatemala.

Seeds and bark of Garcinia kola Heckel (Clusiaceae) are popular products in West and Central Africa. Despite the tree’s economic and cultural importance, little is known about its phenotypic and genotypic variation. This study characterised the morphological and genetic diversity of G. kola in South Cameroon, searching for traits and populations that might be used for domestication. Morphological assessment and amplified fragment length polymorphism (AFLP) markers were applied to characterise diversity among geographic populations from Central and South regions, and between managed and wild trees. AFLP-SURV and analysis of molecular variance results indicated that a major part of genetic diversity is harboured within populations rather than between them. Bayesian analysis, principal component analysis and t-SNE identified three clusters where Ebolowa emerged as the transition population combining features from both regions. Trees from the South demonstrated a higher incidence of domestication-related traits, showing higher genetic diversity compared to the Central region. This suggests that individuals from the South might be more suitable for selection as “elite trees” in future breeding strategies for the species. No significant differences in phenotype and genotype were revealed between wild and managed populations, suggesting G. kola is still in the early stages of its domestication process.

The tree composition in cocoa agroforestry systems (CAFS) in Guatemala is valued for providing a number of ecosystem services. Despite the importance of the trees in these systems, little is known about the tree species richness and its contribution to the conservation of diversity. We studied the botanical composition of CAFS of different ages in the Alta Verapaz department of Guatemala. In total, 70 survey plots with a size of 2500 m² were established. An inventory was carried out in each sampling unit, recording the tree species present and measuring the diameter at breast height (DBH 1.30 m) and the height of each tree. The Importance Value Index (IVI) was calculated and species richness and the similarity between sites were evaluated. A total of 2519 trees, belonging to 59 species and 34 families were identified. The species with the highest IVI was Gliricidia sepium (Jacq.) Kunth. The CAFSs with the highest and lowest species richness were those of 9-12 and 27 years old, respectively (H´=1.99, H´=0.34). This behavior can be explained by the fact that growers work to enrich the agroforestry systems with a broad diversity of species in the first years which they then begin to harvest at around 16 years of age. A discriminant analysis of principal components (DAPC) and the Jaccard Similarity Index were used to show that several AFS were similar in terms of composition and botanical diversity. Given the tree diversity within the CAFS, these can be acknowledged as areas with good potential for the conservation of overall biodiversity. We recommend education programs for local growers about the benefits of shade management during the production cycle of cocoa to preserve the botanical composition and structural complexity of the AFS.

Frosty pod rot (FPR) disease, caused by Moniliophthora roreri, is the most important cocoa disease in the Western Hemisphere. In Guatemala, the presence of the pathogen is attributed to a rapid and clonal dissemination throughout Central America after one or very few introductions of M. roreri from South America. We analyzed the genetic diversity of isolates from the main cocoa producing departments in Guatemala using AFLP. In total, 15 different multilocus genotypes were found among 119 isolates, indicating a low genetic diversity (percentage of polymorphic loci and Nei’s gene diversity, 12.28% and 0.321, respectively). The obtained linkage disequilibrium through the observed and standardized indexes of association (IA and r̄d) confirmed clonality and asexual reproduction in the populations of M. roreri. The discriminant analysis of principal components suggested three genetic groups; nonetheless, the minimum spanning network and fixation index (ΦST = 0.043 P = 0.09) revealed a weak population structure, mainly attributed to high human-mediated gene flow (Nm = 11.13). Given the high mutation rate of M. roreri, constant monitoring of its evolution is suggested along with quarantine practices that limit its dispersal and evaluation of cocoa clones tolerant to the new genotypes of M. roreri, thus preventing increases in losses of Guatemalan cocoa production.