Background: The Caribbean coast of Central America remains an area of malaria transmission caused by Plasmodium falciparum despite the fact that morbidity has been reduced in recent years. Parasite populations in that region show interesting characteristics such as chloroquine susceptibility and low mortality rates. Genetic structure and diversity of P. falciparum populations in the Honduras-Nicaragua border were analysed in this study. Methods: Seven neutral microsatellite loci were analysed in 110 P. falciparum isolates from endemic areas of Honduras (n = 77) and Nicaragua (n = 33), mostly from the border region called the Moskitia. Several analyses concerning the genetic diversity, linkage disequilibrium, population structure, molecular variance, and haplotype clustering were conducted. Results: There was a low level of genetic diversity in P. falciparum populations from Honduras and Nicaragua. Expected heterozigosity (H _e ) results were similarly low for both populations. A moderate differentiation was revealed by the F_ST index between both populations, and two putative clusters were defined through a structure analysis. The main cluster grouped most of samples from Honduras and Nicaragua, while the second cluster was smaller and included all the samples from the Siuna community in Nicaragua. This result could partially explain the stronger linkage disequilibrium (LD) in the parasite population from that country. These findings are congruent with the decreasing rates of malaria endemicity in Central America.

The DNA barcode initiative aims to establish a universal protocol using short genetic sequences to discriminate among animal and plant species. Although many markers have been proposed to become the barcode of plants, the Consortium for the Barcode of Life (CBOL) Plant Working Group recommended using as a core the combination of two portions of plastid coding region, rbcL and matK. In this paper, specific markers based on matK sequences were developed for 7 closely related Annona species of agronomic interest (Annona cherimola, A. reticulata, A. squamosa, A. muricata, A. macroprophyllata, A. glabra and A. purpurea) and the discrimination power of both rbcL and matK was tested using also sequences of the genus Annona available in the Barcode of Life Database (BOLD) data systems. The specific sequences developed allowed the discrimination among all those species tested. Moreover, the primers generated were validated in six additional species of the genus (A. liebmanniana, A. longiflora, A. montana, A. senegalensis, A. emarginata and A. neosalicifolia) and in an interspecific hybrid (A. cherimola x A. squamosa). The development of a fast, reliable and economic approach for species identification in these underutilized subtropical fruit crops in a very initial state of domestication is of great importance in order to optimize genetic resource management.

Traditional agave spirits such as mezcal or tequila are produced all over Mexico using different species of Agave. Amongst them, A. angustifolia is the most popular given its agricultural extension. A. angustifolia is a wild species extensively distributed from North to Central America, and previous studies show that it is highly related to the tequila agave A. tequilana. In different regions of Mexico, A. angustifolia is cultivated under different types and levels of management, and although traditional producers identify several landraces, for the non-trained eye there are no perceivable differences. After interviews with producers from different localities in Jalisco, Mexico, we sampled A. angustifolia plants classified as different landraces, measured several morphological traits, and characterized their genetic differentiation and diversity at the genome-wide level. We included additional samples identified as A. tequilana and A. rhodacantha to evaluate their relationship with A. angustifolia. In contrast with previous studies, our pool of ca 20K high quality unlinked SNPs provided more information and helped us to distinguish different genetic groups that are congruent with the ethnobotanical landraces. We found no evidence to genetically delimitate A. tequilana, A. rhodacantha and A. angustifolia. Our large genome level dataset allows a better understanding of the genetic identity of important A. angustifolia traditional and autochthonous landraces.

Peach (Prunus persica) is an economically important temperate fruit crop due to its edible fruits. Due to the need to develop new varieties better adapted to climate change, it is of great interest to find germplasm adapted to warmer conditions, such as those found in the Canary Islands. Peach was an important crop during the last century in one of those islands (La Palma), but its cultivation has been abandoned in recent years. Currently, commercial production is relict and isolated trees are relegated to family orchards with little management. With the objective to characterize and prevent the loss of local varieties of this crop, peach trees were sampled along La Palma. A total of 89 local peach accessions were prospected and analyzed with 10 single-sequence repeat (SSR) loci, which permitted 28 different genotype profiles to be detected. These genotypes were compared to 95 Spanish peach landraces conserved in an ex situ collection, and 26 additional samples from eight different countries. Results showed that the peach genetic diversity found in La Palma was low. In addition, a relation between La Palma samples and other Spanish peaches was observed, which could indicate the arrival of genetic material from the Iberian Peninsula and subsequent intercrossing and local selection of the genotypes more adapted to the subtropical climate of the island. The population structure reflects a grouping of the samples based on fruit type and geographic origin.

Fruits of the cherimoya tree (Annona cherimola Mill.) were consumed by native cultures in Central America, from where the crop was disseminated to South America in pre-Columbian times. Despite its historical significance and cultivation in subtropical regions worldwide, cherimoya remains an underutilized crop, particularly in its area of origin where the conservation of its genetic diversity is under threat. In this study, we provide a comprehensive overview of the research performed on this fruit tree over the past two decades, shedding light on its current status in terms of commercial production and germplasm conservation efforts in the main cherimoya producing countries in the Americas and Europe.