Cajui (Anacardium spp.) is a native fruit tree (small cashew) of the Brazilian Cerrado and possesses the potential for commercialization. However, cajui exploitation occurs exclusively through ...extractivism in the absence of conservation strategies. The lack of conservation strategies may lead to a decrease in genetic diversity of Anacardium. In this work, the genetic diversity and population structure of three natural populations in Sete Cidades National Park (PNSC; PI, Brazil) were assessed using ISSR analysis of 56 cajui accessions and two A. occidentale accessions (outgroup) from Pacajus (CE, Brazil). A total of 112 markers were obtained, 93 (83.04%) of which were polymorphic. The diversity indices of these populations indicated moderate levels of genetic diversity. According to AMOVA, 96.17% of the genetic variability lay within populations, with low genetic differentiation among populations (ΦST = 0.03828). Furthermore, STRUCTURE analysis indicated the existence of four connected genetic groups. The findings show that the individuals from the three collection sites did not represent different subpopulations, likely due to the high gene flow (Nm = 6.7) favored by the floral biology of Anacardium, pollinators and small-animal seed dispersers. This research identifies genetically divergent individuals (C-03, C-05, C-22, C-26, C-34 and C-39), which should be considered priority individuals for conservation and can inform conservation programs for Anacardium spp.
Parkia platycephala (Fabaceae) is a useful tree. The leaves are rich in protein, fiber and minerals and are good quality, low-cost fodder for animals, making it a great option for animal feed during ...the dry season in Northeast Brazil. In addition, wood is used in small buildings and as fuel. With the aim of exploring genetic variation within the species, we have assessed the molecular and morpho-agronomic characteristics of 10 accessions (F1 - F10) of the species originating from the same location and maintained in the Forage Collection at Embrapa Meio Norte. Clustering analyses based on the amplicons generated by 12 inter simple sequence repeat (ISSR) primers and on 36 qualitative/quantitative markers separated the accessions into two groups, the constituents of which were dependent on the characteristics considered. The most divergent genotypes according to ISSR analysis were F3 and F8. Morpho-agronomic analysis identified F2 and F7 as the most divergent, while the traits that contributed most (36.5%) to total diversity were, in order of importance, mature inflorescence length, stem length, immature inflorescence width, seed weight and pedicel length. The results revealed that there is sufficient genetic variability among the studied accessions. These accessions with greater diversity are candidates for actions that promote the conservation, domestication and genetic improvement of the species.
The mangabeira is a native fruit tree from Brazil with fruits that present significant potential for exploitation. This species is experiencing genetic erosion, which increases the importance of ...elucidating the genetic diversity that exists in mangabeira populations to support conservation programs. Thus, this study aimed to evaluate the diversity and genetic structure of mangabeira populations from the Germplasm Bank of Embrapa Meio-Norte using inter simple sequence repeat (ISSR) markers. A total of 29 accessions from Brazil were characterized, including one from Sergipe, one from Bahia, three from the Distrito Federal, 11 from Piauí and 13 from Paraíba. The 11 ISSR primers provided 166 loci, among which 120 were polymorphic. The analysis of molecular variance (AMOVA) indicated that 69.66% of the observed genetic variability occurred within populations and that the populations showed high genetic differentiation. The results obtained from the STRUCTURE analysis indicated the existence of two genetic groups. The Nei and Shannon indices of genetic diversity varied from 0.15 to 0.24 and from 0.22 to 0.34, respectively. The coefficient of similarity ranged from 0.57 to 0.94, with a mean of 0.76. The mean was used as the cut-off point in the dendrogram, and seven groups were identified. In conclusion, this study demonstrates the presence of low or moderate genetic diversity within the studied mangabeira populations and high genetic differentiation between the populations. The results indicate a need to increase the number of mangabeira population samples from different collection sites as a strategy to achieve more significant results for the conservation and genetic improvement of this species.
The objective of this study was to characterize sixteen genotypes of P. insignis available in the Embrapa Meio-Norte germplasm collection (Teresina, Piauí, Brazil) with respect to 33 morphological ...traits relating to leaves, flowers, branches, fruits and seeds. Phenotypic variance among genotypes was estimated using the Mahalanobis distance technique and the unweighted pair group method with arithmetic mean analysis (UPGMA). The method of Singh (1981) was used to determine which of the traits contributed most to diversity within genotypes. The occurrence of phenotypic variability among P. insignis genotypes indicated that it would be possible to achieve positive gains with selection. The most distant genotypes were BGB 16 and BGB 48, while crosses between genotype BGB 48 and genotypes BGB 32 and BGB 56 offers the greatest potential as parental types for this fruit tree breeding programs . The flesh content, ovary and fruit length , ratio between fruit length and diameter were the characters that most contributed to diversity among the studied genotypes.
The mangaba is a fruit tree with great potential for the northeast of Brazil. Due to the scarcity of improved cultivars, and as it is a species that is still in the process of domestication, ...exploitation has been based on rational and sustainable extractivism by farmer-gatherers. The aim of this study was to analyse the correlations between technological variables of the mangaba, and to carry out an early selection of the genotypes that make up the base population of the mangaba improvement program of Embrapa Meio-Norte. The variables fruit weight, pulp weight and percentage pulp show significant correlation with fruit length and fruit diameter, allowing indirect selection for the first set of variables by means of the latter, which are easily measured. Genotypes 4, 13, 16, 21, 25, 32, 35 and 49 show a positive association with fruit weight, fruit length, fruit diameter, pulp weight and percentage weight, and are therefore candidates for selection. Principal component 1 is associated with fruit weight, fruit length, fruit diameter, skin weight, number of seeds per fruit, seed weight, TTA and pulp weight. These variables can be selected with greater mathematical certainty, since this component concentrates more information regarding variability and is therefore more important.
Conservation systems involving trees enhance the sustainability of tropical soils. However, little is known on the effect of integrated systems with native and exotic trees on soil chemical quality ...in the eastern Amazon. We aimed to measure changes in soil chemical quality in integrated production systems in Pindaré-Mirim, Maranhão, Brazil. This study was carried out in 2017 and 2018, evaluating (i) perennial pasture; (ii) crop–livestock–forest integration-I (CLFI-I)—eucalyptus rows interspersed with maize + Urochloa brizantha intercropping; (iii) CLFI-II—babassu palm trees (Attalea speciosa Mart.) with maize + Megathyrsus maximus intercropping; and (iv) maize + M. maximus intercropping. Soil chemical attributes at depths of 0.00–0.10 m, 0.10–0.20 m, 0.20–0.30 m, and 0.30–0.50 m, forage productivity, and soil cover were evaluated. CLFI-II promoted the highest soil organic matter concentration in topsoil and highest pH, lowest Al3+ levels, and potential acidity (H+Al) at all soil depths. Soil under pasture showed the highest N, K+, Ca2+ concentrations, sum of bases, and cation exchange capacity. Changes in CLFI-II are associated with the babassu palm’s ability to modulate the surrounding environment, giving the species a competitive advantage in anthropic environments. The time of adoption is crucial for improving soil fertility in the Brazilian eastern Amazon. Sustainable production systems in the region must comply with long-term management plans.
The number of microsatellite loci and their allelic diversity contribute to increase accuracy and informativity of genetic estimates, however, the isolation of microsatellite loci is not only ...laborious but also quite expensive. We used (GATA) sub(n) and (GACA) sub(n) tetranucleotide probes and single- and double-enrichment hybridization to construct and screen a genomic library with an increased proportion of DNA fragments containing repeat motifs. Repeats were found using both types of hybridization but the double- enrichment procedure recovered sequences of which 100% contained (GATA) sub(n) and (GACA) sub(n) motifs. Microsatellite loci primers were then designed with an M13R-tail or CAG-tag to produce scorable PCR products with minimal stutter. The approach used in this study suggests that double-enrichment is a worthwhile strategy when isolating repeat motifs from eukaryotic genomes. Moreover, the use of tailed microsatellite primers provides increased resolution for compound microsatellite loci, with a significant decrease in costs.
The mangabeira its figure out among the mains native fruit tree explored by extractivism in Brasil. The objective evaluate the genetic divergence of landraces in orientation of crosses using ...multivariate techinics. The complete random blocks experimental design with four repetitions was used to evaluate twelve quantitative characteristics from twelve genotypes elite of mangabeiras concerning to divergence genetic using the software R (2012). Three groups genetically divergent were composed by biplot graphic and stored by UPGMA cluster analysis (Unweighted Pair-Group Method using Arithmetic Average / Weighted Clustering Method not using the Arithmetic Mean) showing genetic diversity and variability among 12 mangabeira accesses. Forty-four possible crosses are planned among genotypes of genetically dissimilar three groups and six among individuals in group III. Multivariate techniques were appropriate in the study of genetic divergence.
The objective of this study was to characterize sixteen genotypes of P. insignis available in the Embrapa Meio-Norte germplasm collection (Teresina, Piauí, Brazil) with respect to 33 morphological ...traits relating to leaves, flowers, branches, fruits and seeds. Phenotypic variance among genotypes was estimated using the Mahalanobis distance technique and the unweighted pair group method with arithmetic mean analysis (UPGMA). The method of Singh (1981) was used to determine which of the traits contributed most to diversity within genotypes. The occurrence of phenotypic variability among P. insignis genotypes indicated that it would be possible to achieve positive gains with selection. The most distant genotypes were BGB 16 and BGB 48, while crosses between genotype BGB 48 and genotypes BGB 32 and BGB 56 offers the greatest potential as parental types for this fruit tree breeding programs . The flesh content, ovary and fruit length , ratio between fruit length and diameter were the characters that most contributed to diversity among the studied genotypes.
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