Genetic diversity of accessions of the mangaba germplasm bank in Sergipe, BrazilAbstract -The objective of this work was to estimate the genetic variability of mangaba accessions of natural populations, from 11 locations, using RAPD markers. The accessions belong to Banco Ativo de Mangaba of Embrapa Tabuleiros Costeiros, in Itaporanga d'Ajuda, SE, Brazil. A total of 13 primers were used, which generated 82 fragments, of which 78 (95%) were polymorphic. Genetic analysis among regions showed low genetic diversity; however, genetic similarity ranged from 0.02 to 0.91, for the 55 accessions. Divergent groups were identified by UPGMA and ACoP clustering. The least similar accessions were derived from Ipiranguinha (Conde, PB, Brazil) and Preguiça (Indiaroba, SE, Brazil), and the most similar from Jandaíra (Costa Azul, BA, Brazil). From the total, 49 accessions were genetically distinct and six were similar. By using RAPD markers, it was possible to obtain a unique molecular profile, besides estimating the variability among the accessions evaluated. The Banco Ativo de Germoplasma de Mangaba of Embrapa Tabuleiros Costeiros shows low genetic diversity among locations.

The aim of this work was to study the regulation of coffee DREB-like genes in leaves of C. arabica subjected to cold, heat, low relative humidity, exogenous abscisic acid and high light stress, as well as in leaves and roots of drought-tolerant and droughtsusceptible clones of Coffea canephora subjected to water limitation. In C. arabica, CaERF017 was the most expressed gene under low temperatures and relative humidity, while low humidity and high temperatures up-regulated the expression of CaERF053 and CaERF014, respectively. Under water limitation, CcDREB1B, CcRAP2.4, CcERF027, CcDREB1D and CcTINY were the most expressed genes mainly in leaves of drought-tolerant C. canephora. On the other hand, expression of the CcERF016, CcRAP2.4 and CcDREB2F genes was highly up-regulated under water limitation in the roots of drought-susceptible C. canephora clone 22. We previously reported fine-tuned regulation of CcDREB1D promoter haplotypes (HP15, HP16 and HP17) in transgenic C. arabica subjected to low humidity. Here, we investigated the regulation of these haplotypes under high light, cold, heat, and abscisic acid (ABA) stress. In apical buds and leaf guard cells, GUS-stained percentages were higher in pHP16L-transformed plants subjected to low humidity, high light and ABA stress than in pHP17L-and pHP15L-transformed plants. We also reported up-regulated expression of the endogenous CaDREB1D gene for both the cold and low humidity in leaves of pHP16L-transformed C. arabica suggesting a key role of this gene in controlling the responses of coffee plants to abiotic stress probably through an ABA-dependent pathway.Keywords Abiotic stress . Abscisic acid -coffee -DREB -gene expression -promoter Key message: DREB-like genes are differentially expressed in drought-tolerant and susceptible clones of C. canephora subjected to different abiotic stress. In C. arabica, both cold, low humidity and ABA up-regulate CaDREB1D gene expression.

Cambui (Myrciaria tenella O. Berg) is a native species from Brazil, which belongs to the family Myrtaceae. Molecular characterization is one of the most used tools for the study of the biotechnological potential of species because the diversity level between individuals can be inferred. Analysis of genetic diversity is fundamental to the direction of the strategies necessary to form and maintain a germplasm. This study aimed to evaluate the genetic diversity in a natural population of cambui using inter-simple sequence repeat (ISSR) molecular markers. The natural population, which provided the plant material, is found at the Private Reserve of Natural Heritage of Caju, which belongs to the experimental field of Embrapa Tabuleiros Costeiros, in the municipality of Itaporanga d'Ajuda, SE, Brazil. Young leaves of each individual were collected for DNA extraction and analysis of PCR-ISSR. Thirty primers were tested and the top 10 were selected. The use of these primers resulted in 71 fragments with 98.3% polymorphism. Similarity of individuals ranged between 0.30 and 0.92. The most similar individuals were C13 and C17 and the most distant were C1 and C41. Through UPGMA, six distinct groups were identified. This information may be used for conservation of these genetic resources, germplasm exchange, creation of germplasm bank and in future studies with this species.

ABSTRACT. Brazil has about 300 Croton species in different types of vegetation. Croton tetradenius Baill., which is endemic to the Northeast region and predominant in the Caatinga vegetation, stands out among the several species of this genus. Considering the importance of knowing the genetic variability of a species, the objective of this study was to analyze the genetic diversity of the genotypes of natural populations of C. tetradenius in the State of Sergipe, using ISSR molecular markers. Forty individuals were sampled in four natural populations of the State of Sergipe, Brazil. Thirteen primers were used for DNA amplification using ISSR-PCR, totaling 77 amplified fragments, of which 94.8% were polymorphic. Results of the cluster analysis obtained by the Jaccard's similarity index, using the UPGMA method, resulted in the formation of six distinct clusters. Analysis of molecular variance (AMOVA), used to estimate the genetic variability among populations, revealed significant genetic variance (P < 0.01) between and within the 2 C.S. Almeida-Pereira et al.Genetics and Molecular Research 16 (2): gmr16029602 studied populations, and most of the genetic diversity was found (87%) within populations. According to the Jaccard's similarity index, none of the studied plants was genetically identical. CTE210 and CTE305 presented high similarity index (0.76), while CTE105 presented low similarity index (<0.16) with all related individuals. ISSR markers were efficient and allowed the formation of a molecular profile, and had sufficient polymorphism to estimate the genetic variability between the accessions of the studied populations.

-The cambuí tree (Myrciaria tenella O. Berg) is native to Brazil and its fruits are harvested by extraction for fresh consumption in the state of Sergipe (Brazil). Because of the regional importance of the species, this work aims to characterize the cambuí fruits and seeds. The fruits were harvested mature from native trees in the Reserva do Caju Experimental Field, on Itaporanga d'Ajuda (Sergipe, Brazil), belonging to Embrapa Tabuleiros Costeiros. Two hundred fruits and seeds were biometrically analyzed. In addition, we evaluated the fruit, pulp, and seed color based on RHS Color Chart.