The genetic background of the Brazilian population is mainly characterized by three parental populations: European, African, and Native American. The aim of this study was to overview the genetic ancestry estimates for different Brazilian geographic regions and analyze factors involved in these estimates. In this systematic scoping review were included 51 studies, comprehending 81 populations of 19 states from five regions of Brazil. To reduce the potential of bias from studies with different sampling methods, we calculated the mean genetic ancestry weighted by the number of individuals. The weighted mean proportions of European, African, and Native American ancestries were 68.1%, 19.6%, and 11.6%, respectively. At the regional level, the highest European contribution occurred in the South, while the highest African and Native American contributions occurred in the Northeastern and Northern regions, respectively. Among states in the Northeast region, Bahia and Ceara showed significant differences, suggesting distinct demographic histories. This review contributes for a broader understanding of the Brazilian ancestry and indicates that the ancestry estimates are influenced by the type of molecular marker and the sampling method.

/pdf/a-systematic-scoping-review-of-the-genetic-ancestry-of-the-4bpy2c80s3.pdf

A systematic scoping review of the genetic ancestry of the Brazilian population.

The abiotic stresses such as unfavorable temperature, drought, flood, salinity, and heavy metal stress are considered as major factors causing a huge impression on crop growth and productivity. The abiotic stresses can reduce as much as 50% of benefits for some important crops in the world through altering the physiological, morphological, biochemical, and molecular process of plants. Therefore, escape, avoidance, and tolerance mechanisms are very important for plants to survive against abiotic stresses. Crop wild relatives (CWRs) are considered as wild plant species of the same genus (mostly with the same gene pool) of a crop, which play a vital role in the development of crop species for various hostile environments. The gene pool CWRs wild relatives is considered in the choice of crops for today, which is simply a selection from vast. The CWRs helped a lot in the domestication of selected species of present day’s crops and played a vital role in feeding the human civilization. Under the present scenario of climate change, CWRs have got a vital dimension in crop improvement for combatting the adverse effects of climatic threats. Therefore, CWRs became more useful in molecular breeding for the sustainability of crop production in the modern era of climate change. In the chapter, we have been discussed on the wild relatives of plants as sources for the development of abiotic stress tolerance in plants.

Wild relatives of plants as sources for the development of abiotic stress tolerance in plants

Closely related species with parapatric elevational ranges are ubiquitous in tropical mountains worldwide. The gradient speciation hypothesis proposes that these series are the result of in situ ecological speciation driven by divergent selection across elevation. Direct tests of this scenario have been hampered by the difficulty inferring the geographic arrangement of populations at the time of divergence. In cichlids, sticklebacks and Timema stick insects, support for ecological speciation driven by other selective pressures has come from demonstrating parallel speciation, where divergence proceeds independently across replicated environmental gradients. Here, we take advantage of the unique geography of the island of New Guinea to test for parallel gradient speciation in replicated populations of Syma kingfishers that show extremely subtle differentiation across elevation and between historically isolated mountain ranges. We find that currently described high-elevation and low-elevation species have reciprocally monophyletic gene trees and form nuclear DNA clusters, rejecting this hypothesis. However, demographic modelling suggests selection has likely maintained species boundaries in the face of gene flow following secondary contact. We compile evidence from the published literature to show that although in situ gradient speciation in labile organisms such as birds appears rare, divergent selection and post-speciation gene flow may be an underappreciated force in the origin of elevational series and tropical beta diversity along mountain slopes.

/pdf/speciation-and-gene-flow-across-an-elevational-gradient-in-4cxechx2kw.pdf

Speciation and gene flow across an elevational gradient in New Guinea kingfishers.

Since many fungal pathogens develop resistance to fungicides, novel and low-cost alternative methods to improve plant health and fitness need to be developed. An approach to improve productivity in crops is to stimulate the plant's own defence mechanisms via priming. Therefore, we investigated if a fermentation-based elicitor could prime plant defences against powdery mildew in wheat by inducing the expression of endogenous defence-related genes. Wheat seedlings were spray-treated with a fermentation-based elicitor 8 days prior to inoculation with powdery mildew. Disease assays showed a significantly reduced number of powdery mildew pustules were formed on wheat treated with the mixed elicitor. In vitro sensitivity assays tested the ability of powdery mildew conidia to germinate on agar amended with the fermentation-based product and concluded that fungal germination and differentiation were also inhibited. Tissue samples were taken at time points pertaining to different developmental stages of powdery mildew infection. Significantly higher expression of PR genes (PR1, PR4, PR5, and PR9) was observed in the microbial fermentation mixture-treated plants compared with untreated plants. These genes are often associated with the elicitation of plant defence responses to specific biotrophic pathogens, such as powdery mildew, suggesting an elicitor-mediated response in the wheat plants tested. The product components were assessed, and the components were found to act synergistically in the microbial fermentation mixture. Therefore, this fermentation-based elicitor provides an effective method for powdery mildew control.

/pdf/a-microbial-fermentation-mixture-primes-for-resistance-3tyocmfxa4.pdf

A microbial fermentation mixture primes for resistance against powdery mildew in wheat

1. Many developing countries harbour large numbers of species that face little-understood, gradual changes in their environment, including chronic anthropo genic disturbance (CAD), a high frequency but low intensity form of disturbance. These countries also lack the resources to study each species, so conservation practices have been generalized, assuming that complete taxonomic groups may be managed in the same ways. This approach could be justified if closely related species respond similarly to threats. We assessed if related species respond simi larly to CAD, whether this affects phylogenetic diversity and if such patterns occur in different systems. 2. Species’ identity and abundance was recorded in 59 sites differing in CAD inten

https://besjournals.onlinelibrary.wiley.com/doi/pdf/10.1111/1365-2664.13151

Related plant species respond similarly to chronic anthropogenic disturbance: Implications for conservation decision-making

This study was conducted with the objective of evaluating the growth of six strains of Lentinula edodes (LE1, LE2, LE3, LE4, LE5 and LE6) in five culture media and characterizes strains for enzyme production. The culture medium that provided the best mycelial growth of the strains was used for semi-quantitative tests of ligninase and cellulase activity. Samples for enzyme assays and determination of total proteins were collected at 7, 14, 21 and 28 days of incubation to building an enzymatic curve. The strain LE5 is the most aggressive, with higher mycelial growth rate and mycelial mass production in the basic medium added of 0.01% yeast extract. The addition of biotin and thiamine to the culture medium is not sufficient to substitute yeast extract. The performance of the strains with respect to the production of cellulase and ligninase was different. The LE6 strain excelled in the production of laccase, manganese peroxidase and β-glucosidase with 28 days of incubation and endo-β-1,4-glucanase with 14 days of incubation, while strain LE5 excelled in the production of exo-β-1,4-glucanase with 7 days of incubation.

Ligninase and cellulase activity of Lentinula edodes (Berk.) pegler strains in different culture media

The distribution of mitochondrial DNA (mtDNA) lineages in Brazil is heterogeneous due to different regional colonization dynamics. Northeastern Brazil, although being an important region in terms of human imigration and ethnic admixture, has little information regarding its population mtDNA composition. Here, we determine which mitochondrial lineages contributed to the formation of the Northeastern Brazilian population. Our sample consisted of 767 individuals distributed as follows i) 550 individuals from eight Northeastern states (Piaui, Ceara, Rio Grande do Norte, Paraiba, Pernambuco, Alagoas, Sergipe, and Bahia) which were sequenced for mtDNA hypervariable segments I, II, and III; ii) 217 individuals from Alagoas and Pernambuco (previously published data). Data analysis was performed through sequence alignment and Haplogrep 2.0 haplogroup assignment tools. Furthermore, maternal ancestry distribution was contextualized and, when possible, related to historical events to better understand the biological interactions and population dynamics that occurred in this region since the beginning of colonization. Unexpectedly, Amerindian mitochondrial ancestry was the highest in the Northeastern region overall, followed by African, European and non-Amerindian Asian, unlike previous results for this region. Alagoas and Pernambuco states, however, showed a larger African mtDNA frequency. The Northeastern region showed an intraregional heterogeneous distribution regarding ancestral groups, in which states/mesoregions located to the north had a prevalent Amerindian ancestral frequency and those to the south had predominance of African ancestry. Moreover, results showed great diversity of European haplogroups and the presence of non-Amerindian Asian haplogroups. Our findings are in disagreement with previous investigations that suggest African mitochondrial ancestry is the most prevalent in the Brazilian Northeast. The predominance of Amerindian lineages exemplifies the importance of indigenous women in the formation of the population, despite intense African slave entry and conflicts with European settlers. The variable distribution of ancestral groups observed in the Northeast is in accordance with historical records showing the similarities with colonization dynamics occurred in the Amazon region and the Brazilian Southeast. Moreover, the variety of European haplogroups suggests multiple origins of founding groups, specially those found in Western European populations.

/pdf/mtdna-structure-the-women-who-formed-the-brazilian-northeast-1ce11aqzky.pdf

mtDNA structure: the women who formed the Brazilian Northeast

The current Brazilian population is the product of centuries of admixture between intercontinental founding groups. Although previous results have revealed a heterogeneous distribution of mitochondrial lineages in the Northeast region, the most targeted by foreign settlers during the sixteenth century, little is known about the paternal ancestry of this particular population. Considering historical records have documented a series of territorial invasions in the Northeast by various European populations, we aimed to characterize the male lineages found in Brazilian individuals in order to discover to what extent these migrations have influenced the present-day gene pool. Our approach consisted of employing four hierarchical multiplex assays for the investigation of 45 unique event polymorphisms in the non-recombining portion of the Y-chromosome of 280 unrelated men from several Northeast Brazilian states. Primary multiplex results allowed the identification of six major haplogroups, four of which were screened for downstream SNPs and enabled the observation of 19 additional lineages. Results reveal a majority of Western European haplogroups, among which R1b-S116* was the most common (63.9%), corroborating historical records of colonizations by Iberian populations. Nonetheless, FST genetic distances show similarities between Northeast Brazil and several other European populations, indicating multiple origins of settlers. Regarding Native American ancestry, our findings confirm a strong sexual bias against such haplogroups, which represented only 2.5% of individuals, highly contrasting previous results for maternal lineages. Furthermore, we document the presence of several Middle Eastern and African haplogroups, supporting a complex historical formation of this population and highlighting its uniqueness among other Brazilian regions. We performed a comprehensive analysis of the major Y-chromosome lineages that form the most dynamic migratory region from the Brazilian colonial period. This evidence suggests that the ongoing entry of European, Middle Eastern, and African males in the Brazilian Northeast, since at least 500 years, was significantly responsible for the present-day genetic architecture of this population.

/pdf/new-insights-on-intercontinental-origins-of-paternal-4qxcjfwbte.pdf

New insights on intercontinental origins of paternal lineages in Northeast Brazil.

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Ligninase and cellulase activity of Lentinula edodes (Berk.) pegler strains in different culture media

mtDNA structure: the women who formed the Brazilian Northeast

New insights on intercontinental origins of paternal lineages in Northeast Brazil.