Biology subjects

Zucchi, M. I.

Publications and source records attributed to Zucchi, M. I..

10 recordsLinked to original sources

bioRxiv2025

First chromosome scale genome of Acrocomia aculeata

The Arecaceae family comprises economically, and ecologically significant palm species widely distributed across tropical and subtropical regions. Among them, Acrocomia aculeata, commonly known as Macauba, has gained attention due to its high oil yield, environmental adaptability, and potential applications in sustainable agriculture and bioenergy production. This study presents the first chromosome scale genome assembly of A. aculeata and the first reference genome of the genus, using Oxford Nanopore Technologies sequencing, PacBio HiFi and Hi-C proximity ligation data. The genome covers 1.94 Gbp in the 15 pseudochromosomes, with N50 of 143.43 Mbp, achieving a base quality (QV) of 76.4 and a k-mer completeness of 90.58% of PacBio HiFi data, with k=21. Interspersed repetitive regions represent 77.36% of the total genome, with long terminal repeat (LTRs) accounting for 54.98%. A total of 28.215 protein-coding genes were predicted. The genome was validated with BUSCO, achieving a completeness of 98.9% for predicted proteins. The first chromosome scale genome of Macauba provide new insights and breakthroughs for studies of conservation genomics and plant breeding programs.

genomics↗

bioRxiv2024

Sample Size Impact (SaSii): an R script for estimating optimal sample sizes in population genetics and population genomics studies

Obtaining large sample sizes for genetic studies can be challenging, time-consuming, and expensive. However, small sample sizes may generate biased or imprecise results. Many studies have suggested the minimum sample size necessary to obtain robust and reliable results, but it is not possible to define one ideal minimum sample size that fits all studies. Here, we aim to present SaSii (Sample Size Impact), a R script to help researchers to define minimum sample size and to indicate minimum sample size patterns for some taxa groups. The patterns were obtained by analyzing previously published datasets with SaSii and can be used as a starting point for the sample design of population genetics and genomic studies. Our results showed that it is possible to estimate an adequate sample size that accurately represents the real population and does not require the scientist to take time to write any program code, extract and sequence samples or use population genetics programs, making it easier to gather this information. We also confirmed that sample sizes of five to twenty-five for SNP and fifteen to thirty for SSR can be used for most plant species, giving a better direction for new studies.

bioinformatics↗

bioRxiv2024

Genetic variations associated with adaptation processes in Acrocomia palms: A comparative study across the Neotropic for future crop improvement

Population genetic research has evolved, focusing on selection processes using single nucleotide polymorphisms (SNP) genotyping techniques to study crop traits and domestication. This study explores the adaptation process of three neotropical palms of Acrocomia, a genus that has high potential for oil extraction. Our research focuses on their genetic structure, evolutionary significance, and implications of the selection signatures for breeding efforts. We employed Genotyping-by-Sequencing (GBS) with a focus on outlier SNP markers for identifying adaptive genetic processes in A. aculeata, A. totai, and A. intumescens across the Neotropic. Our results reveal two major gene pools in A. aculeata, a North American and a South American group mainly influenced by dispersal and biogeographic barriers, with putative selective signatures linked to fatty acid and carotenoid biosynthesis, pathogen resistance, and environmental stress adaptation. A. totai presented a pronounced genetic structure, with SNPs under selection indicating a recent diversification driven by climatic and geological factors, especially in the Pantanal biome. A. intumescens displays genetic structuring shaped by the endemic process of biogeographic barriers within the Caatinga biome, with potential shared ancestry with A. aculeata. Correlations between allele frequencies and climatic variables highlight adaptation to diverse environments, principally semi-arid, with the annual mean temperature being one of the most influential. Candidate genes associated with fatty acid and carotenoid biosynthesis, as well as pathogen resistance and drought tolerance, indicate targets for domestication. Despite challenges in reduced representation sequencing, this study underlines the potential of Acrocomia as a novel crop, offering prospects in oil production, biofuels, and sustainable agriculture. Future efforts should prioritize whole-genome sequencing and genotype-environment interaction studies to realize the full potential of Acrocomia in sustainable development and renewable energy production.

genomics↗

bioRxiv2024

Genome-Wide Association Insights into the Genomic Regions Controlling Oil Production Traits in Acrocomia aculeata (neotropical native palm)

Macauba (Acrocomia aculeata) is a non-domesticated neotropical palm that has been attracting attention for economical use due to its great potential for oil production comparable to the commercially used oil palm (Elaeis guineenses). The discovery of associations between quantitative trait loci and economically important traits represents an advance toward macauba domestication. Pursuing this advance, this study performs single-trait and multi-trait GWAS models to identify candidate genes related to oil production traits in macauba. We randomly selected 201 palms from a natural population and analysed 13 traits related to fruit production, processing, and oil content. Genotyping was performed following the genotyping-by- sequencing protocol. SNP calling was performed using three strategies since macauba doesnt have a reference genome: using i) de novo pipeline, ii) Elaeis guineenses Jacq. reference genome, and iii) transcriptome of Acrocomia aculeata. Single-trait analysis was fitted using five models from GAPIT, while multi-trait analysis was fitted using a multivariate stepwise method implemented in the software TASSEL. Multi-trait analyses were conducted in all pairwise trait combinations. Results showed statistically significant differences in all phenotypic traits studied, and heritability values ranged from 0.63 to 0.95. Gene annotation detected 15 candidate genes in seven traits in the single-trait GWAS and four candidate genes in 10 trait combinations in the multi-trait GWAS. We provide new insights on genomic regions that mapped candidate genes involved in macauba oil production phenotypes. Associated markers to the traits of interest may be valuable resources for the development of marker-assisted selection in macauba for both domestication and pre-breeding purposes.

genetics↗

bioRxiv2022

Complete chloroplast genomes and phylogeny in three Euterpe palms (E. edulis, E. oleraceae and E. precatoria) from different Brazilian biomes

The Brazilian palm fruits and hearts-of-palm of Euterpe edulis, E. oleracea and E. precatoria are an important source for agro-industrial production, but overexploitation requires conservation strategies to maintain genetic diversity. Chloroplast genomes have conserved sequences, which are useful to explore evolutionary questions. Besides the plastid DNA, genome skimming allows the identification of other genomic resources, such as single nucleotide polymorphisms (SNPs), providing information about the genetic diversity of species. We sequenced the chloroplast genome and identified gene content in the three Euterpe species. We performed comparative analyses, described the polymorphisms among the chloroplast genome sequences (repeats, indels and SNPs) and performed a phylogenomic inference based on 55 palm species chloroplast genomes. Finally, using the remaining data from genome skimming, the nuclear and mitochondrial reads, we identified SNPs and estimated the genetic diversity among these Euterpe species. The Euterpe chloroplast genomes varied from 159,232 to 159,275 bp and presented a conserved quadripartite structure with high synteny with other palms. In a pairwise comparison, we found a greater number of insertions/deletions (indels = 93 and 103) and SNPs (284 and 254) between E. edulis/E. oleracea and E. edulis/E. precatoria when compared to E. oleracea/E. precatoria (58 indels and 114 SNPs). Also, the phylogeny indicated a closer relationship between E. oleracea/E. precatoria. The nuclear and mitochondrial genome analyses identified 1,077 SNPs and high divergence among species (FST = 0.77), especially between E. edulis and E. precatoria (FST = 0.86). These results showed that, despite the few structural differences among the chloroplast genomes of these Euterpe palms, a differentiation between E. edulis and the other Euterpe species can be identified by point mutations. This study not only brings new knowledge about the evolution of Euterpe chloroplast genomes, but also these new resources open the way for future phylogenomic inferences and comparative analyses within Arecaceae.

evolutionary biology↗

bioRxiv2021

Selective signatures and high genome-wide diversity in traditional Brazilian manioc (Manihot esculenta Crantz) varieties

Knowledge about crops genetic diversity is essential to promote effective use and conservation of their genetic resources, because genetic diversity enables farmers to adapt their crops to specific needs and is the raw material for breeding efforts. Currently, manioc (Manihot esculenta ssp. esculenta) is one of the most important food crops in the world and has the potential to help achieve food security in the context of on-going climate changes. In this study we assessed the patterns of genome-wide diversity of traditional Brazilian manioc varieties conserved in the gene bank of the Luiz de Queiroz College of Agriculture, University of Sao Paulo. We used single nucleotide polymorphisms to evaluate the organization of genetic diversity and to identify selective signatures contrasting varieties from different biomes with samples of maniocs wild relative M. esculenta ssp. flabellifolia. We identified signatures of selection putatively associated with resistance genes, plant development and response to abiotic stresses. This presumed adaptive variation might have been important for the initial domestication and for the crops diversification in response to cultivation in different environments. The neutral variation revealed high levels of genetic diversity within groups of varieties from different biomes and low to moderate genetic divergence among biomes. These results reflect the complexity of maniocs biology and its evolutionary dynamics under traditional cultivation. Our results exemplify how the smallholder practices contribute to the conservation of maniocs genetic resources, maintaining variation of potential adaptive significance and high levels of neutral genetic diversity.

genetics↗

bioRxiv2020

Whole-genome SNP analysis elucidates the genetic population structure and diversity of Acrocomia species

Acrocomia (Arecaceae) is a genus widely distributed in tropical and subtropical America that has been achieving economic interest due to the great potential of oil production of some of its species. In particular A. aculeata, due to its vocation to supply oil with the same productive capacity as the oil palm even in areas with water deficit. Although eight species are recognized in the genus, the taxonomic classification based on morphology and geographic distribution is still controversial. Knowledge about the genetic diversity and population structure of the species is limited, which has limited the understanding of the genetic relationships and the orientation of management, conservation, and genetic improvement activities of species of the genus. In the present study, we analyzed the genomic diversity and population structure of seven species of Acrocomia including 117 samples of A. aculeata covering a wide geographical area of occurrence, using single nucleotide Polymorphism (SNP) markers originated from Genotyping By Sequencing (GBS). The genetic structure of the Acrocomia species were partially congruent with the current taxonomic classification based on morphological characters, recovering the separation of the species A. aculeata, A. totai, A. crispa and A. intumescens as distinct taxonomic groups. However, the species A. media was attributed to the cluster of A. aculeata while A. hassleri and A. glauscescens were grouped together with A. totai. The species that showed the highest and lowest genetic diversity were A. totai and A. media, respectively. When analyzed separately, the species A. aculeata showed a strong genetic structure, forming two genetic groups, the first represented mainly by genotypes from Brazil and the second by accessions from Central and North American countries. Greater genetic diversity was found in Brazil when compared to the other countries. Our results on the genetic diversity of the genus are unprecedented, as is also establishes new insights on the genomic relationships between Acrocomia species. It is also the first study to provide a more global view of the genomic diversity of A. aculeata. We also highlight the applicability of genomic data as a reference for future studies on genetic diversity, taxonomy, evolution and phylogeny of the Acrocomia genus, as well as to support strategies for the conservation, exploration and breeding of Acrocomia species and in particular A. aculeata.

genetics↗

bioRxiv2020

Genetic structure and molecular diversity of Brazilian grapevine germplasm: management and use in the breeding programs

The management of germplasm banks is complex, especially when many accessions are involved. Microsatellite markers are an efficient tool for assessing the genetic diversity of germplasm collections, optimizing their use in breeding programs. This study genetically characterizes a large collection of 410 grapevine accessions maintained at the Agronomic Institute of Campinas (IAC) (Brazil). The accessions were genotyped with 17 highly polymorphic microsatellite markers. Genetic data were analyzed to determine the genetic structure of the germplasm, quantify its allelic diversity, suggest the composition of a core collection, and discover cases of synonymy, duplication, and misnaming. A total of 304 alleles were obtained, and 334 unique genotypes were identified. The molecular profiles of 145 accessions were confirmed according to the literature and databases, and the molecular profiles of more than 100 genotypes were reported for the first time. The analysis of the genetic structure revealed different levels of stratification. The primary division was between accessions related to Vitis vinifera and V. labrusca, followed by their separation from wild grapevine. A core collection of 120 genotypes captured 100% of all detected alleles. The accessions selected for the core collection may be used in future phenotyping efforts, in genome association studies, and for conservation purposes. Genetic divergence among accessions has practical applications in grape breeding programs, as the choice of relatively divergent parents will maximize the frequency of progeny with superior characteristics. Together, our results can enhance the management of grapevine germplasm and guide the efficient exploitation of genetic diversity to facilitate the development of new grape cultivars for fresh fruits, wine, and rootstock.

molecular biology↗

bioRxiv2020

Geographic and environmental contributions to genomic divergence in mangrove forests

Assessing the relative importance of geographical and environmental factors to the spatial distribution of genetic variation can provide information about the processes that maintain genetic variation in natural populations. With a globally wide but very restricted habitat distribution, mangrove trees are a useful model for studies aiming to understand the contributions of these factors. Mangroves occur along the continent-ocean interface of tropical and subtropical latitudes, regions considered inhospitable to many other types of plants. Here, we used landscape genomics approaches to investigate the relative contributions of geographical and environmental variables to the genetic variation of two black mangrove species, Avicennia schaueriana and Avicennia germinans, along the South American coast. Using single nucleotide polymorphisms, our results revealed an important role of ocean currents and geographical distance in the gene flow of A. schaueriana and an isolation-by-environment pattern in the organization of the genetic diversity of A. germinans. Additionally, for A. germinans, we observed significant correlations between genetic variation with evidence of selection and the influence of precipitation regimens, solar radiation and temperature patterns. These discoveries expand our knowledge about the evolution of mangrove trees and provide important information to predict future responses of coastal species to the expected global changes during this century.

genomics↗

bioRxiv2018

Environment-driven genomic and trait divergence in a neotropical mangrove highlight differential sensitivities to climate change

Local adaptation is often a product of environmental variations in the geographical space and has implications for biodiversity conservation. We investigated the role of latitudinal heterogeneity in climate on the organization of genetic and phenotypic variation in the dominant coastal tree, Avicennia schaueriana. In a common garden experiment, samples from an equatorial region, marked by rainy/dry seasons, accumulated less biomass, showed lower stomatal conductance and transpiration, narrower xylem vessels, smaller leaves and higher reflectance of long wavelengths (red light) on the stem epidermis, than samples from a subtropical region, marked by warm/cold seasons. Transcriptome differences identified between trees sampled under field conditions at equatorial and subtropical sites, were enriched in functional categories as responses to temperature, solar radiation, water deficit, photosynthesis and cell wall biosynthesis. The diversity based on thousands of SNP loci revealed a north-south genetic structure. Remarkably, signatures of selection were identified in loci associated with photosynthesis, anthocyanin accumulation and the responses to osmotic and hypoxia stresses. Our results suggest the existence of divergence in key resource-use characteristics, likely driven by climate seasonality, based on water-deficit and solar radiation. These findings provide a basis for conservation plans and for predictions for coastal plant responses to climate change.

plant biology↗