Biology subjects

Furtado, A.

Publications and source records attributed to Furtado, A..

17 recordsLinked to original sources

bioRxiv2026

Genomic and pedigree-based approaches to predict parental breeding values for nut and kernel traits in almond (Prunus dulcis Mill. D. A. Webb)

The self-incompatibility, perennial growth habit, large tree size, and long juvenility present challenges in applying traditional breeding approaches in almond (Prunus dulcis Mill. D. A. Webb). Moreover, nut and kernel traits in almond are mainly controlled by a large number of small-effect quantitative trait loci (QTLs) and improving complex traits through conventional breeding approaches is slow and often inefficient. Genome-wide selection represents a promising strategy to enhance the efficiency of cultivar identification and selection of superior parents in almond breeding programs by estimating the breeding values (BVs) at early maturity. The main aim of this study was to implement genomic (GBLUP) and pedigree-based (ABLUP) prediction approaches to estimate BVs to identify the superior parental candidates for improving nut and kernel traits in almond. Here, we estimated BVs for nine traits that are commonly used in the primary evaluation stage of the almond breeding using genomic data from 61 parents and phenotypic data of 15,281 progeny derived from 205 unique families. Breeding values obtained from both approaches showed a strong correlation (r [≥] 0.94) for all traits except shell seal (r = 0.87). The population structure analysis conducted using high-quality 90K single nucleotide polymorphisms (SNPs) indicated clear separation of the Californian, European and some old Australian almond cultivars, with considerable admixture across some cultivars. Following further validation, both prediction approaches could be useful in early identification of superior candidates. The slightly higher breeding values obtained using the GBLUP compared to the ABLUP approach suggest that accounting for within-family variations and realised genomic relationships can enhance prediction accuracy, reliability, and overall genomic prediction performance in almond.

genetics↗

bioRxiv2025

Chromosome-scale haplotype genome assemblies for the Australian mango 'Kensington Pride' 1 and a wild relative, Mangifera laurina, provide insights into anthracnose-resistance and volatile 2 compound biosynthesis genes

Mango (Mangifera indica) is one of the most popular fruits cultivated in tropical and subtropical regions of the world. The availability of reference genomes helps to identify the genetic basis of important traits. Here we report assembled high-quality chromosome-level genomes for the Australian mango cultivar Kensington Pride, and M. laurina; a wild relative, which shows resistance to anthracnose disease. PacBio HiFi sequencing with higher genome coverage enabled the assembly of both genomes with 100% completeness. Genome sizes of Kensington Pride and M. laurina were 367 Mb and 379 Mb, respectively, with all 20 chromosomes in both genomes having telomeres at both ends. K-mer analysis revealed that these genomes are highly heterozygous and significant structural variations were identified between Kensington Pride, M. laurina, and the recently published genome of the cultivar Irwin. Functional annotation identified key genes involved in carotenoid, anthocyanin, and terpenoid biosynthesis, responsible for fruit color and flavour in mango. Furthermore, the presence of a SNP in {beta}-1,3-glucanase 2 gene associated with anthracnose resistance was analyzed. Whole genome duplication analysis confirmed that mangoes have undergone two polyploidization events during their evolution. Analysis revealed a conserved pattern of colinear genes, although many colinear blocks were also identified on non-homologous chromosomes. Practitioner PointsO_LIPacBio HiFi sequencing and high coverage produced genomes for Kensington Pride mango and M. laurina with 100% completeness, identifying all the telomeres in the assembled chromosomes. C_LIO_LISignificant structural variations were identified between Kensington Pride, M. laurina, and the published Irwin genome. C_LIO_LIGenes linked in the biosynthesis of unique terpenoids were identified, and the structural differences in the annotated {beta}-1,3-glucanase 2 genes associated with anthracnose resistance provide a resource for gene expression analysis in susceptible and resistant cultivars. C_LI

plant biology↗

bioRxiv2025

Genetic diversity and variation in heterozygosity in Macadamia

BackgroundMacadamia is a diploid (2n =28) rainforest tree of the Proteaceae family, native to Australia. Single-nucleotide polymorphisms (SNPs) have proven to be effective tools for evaluating genetic diversity and heterozygosity. SNPs from the whole genome were used to determine allelic diversity within different species and breeding populations, and to investigate the heterozygosity of genotypes ResultsA total of 349 samples, including wild and domesticated genotypes, were whole genome sequenced, generating 4,180,786 - 7,661,269, 2,446,762 - 7,356,187, 2,829,944 - 4,391,600, 1601519 - 3,182,089 and 3,123,715 to 9,620,640 single nucleotide polymorphism (SNP) positions at the whole genome level for M. integrifolia, M. tetraphylla, M. ternifolia, M. jansenii and the domesticated cultivars and breeding selections respectively. The overall SNP diversity for wild M. integrifolia, M. tetraphylla, M. ternifolia and M. jansenii was 4.43%, 4.33%, 1.80% and 1.1%, respectively. Domesticated M. integrifolia showed an overall SNP diversity of 3.4%, 1.03% lower than wild M. integrifolia, providing evidence of a genetic bottleneck during domestication. Genetic diversity at the individual level for the domesticated gene pool varied from 0.4% to 1.24%, with an overall diversity of 6.10%. Results across different breeding groups revealed that the Australian breeding selections (NMBPA) had the highest diversity, and HAES cultivars had the lowest diversity. Wild M. integrifolia and M. tetraphylla exhibited heterozygosity ranging from 0.36% to 0.71% and 0.30% to 0.71% respectively. The two non-edible species, M. ternifolia and M. jansenii, displayed relatively low heterozygosity (From 0.29% to 0.42% and 0.19% to 0.34% respectively). Domesticated macadamia exhibited a wide range of heterozygosity (0.33% to 1.15%). Additionally, heterozygosity correlated with yield efficiency (kernel yield/tree volume), cumulative kernel yield at age 8 and cumulative nut in shell (NIS) yield at age 8 and showed that performance increased with heterozygosity to an optimal level and declined thereafter. ConclusionThese findings confirmed that there is substantial genetic variation among the different macadamia genotypes. The results also revealed that the greatest diversity is present in wild germplasm. The data will greatly support future genome-wide studies and breeding programs.

plant biology↗

bioRxiv2024

Centromeres are Hotspots for Chromosomal Inversions and Breeding Traits in Mango

Chromosomal inversions can preserve combinations of favorable alleles by suppressing recombination. Simultaneously, they reduce the effectiveness of purifying selection enabling deleterious alleles to accumulate. This study explores how areas of low recombination, including centromeric regions and chromosomal inversions, contribute to the accumulation of deleterious and favorable loci in 225 Mangifera indica genomes from the Australian Mango Breeding Program. Here, we identify 17 chromosomal inversions that cover 7.7% (29.7Mb) of the M. indica genome: eight pericentric (inversion includes the centromere) and nine paracentric (inversion is on one arm of the chromosome). Our results show that these large pericentric inversions are accumulating deleterious loci, while the paracentric inversions show deleterious levels above and below the genome wide average. We find that despite their deleterious load, chromosomal inversions contain small effect loci linked to variation in crucial breeding traits, indicating that chromosomal inversions have likely facilitated their selection. The results from this study have important implications for selective breeding of favorable combinations of alleles in regions of low recombination. Significance StatementChromosomal inversions and other low recombination regions of the genome can drive trait evolution. Fewer recombination events can assist in maintaining favorable combinations of alleles, but it can also make disentangling favorable and deleterious alleles difficult. Understanding whether these low recombination regions contain favorable or deleterious loci could drive our decision to increase or decrease the frequency of these regions in target breeding populations. Breeding for large segments of the genome based on presence or absence of an inversion can rapidly drive large trait differences within few generations. Harnessing the impact of large low recombination regions of the genome could have major implications for future genetic improvement in breeding.

genomics↗

bioRxiv2024

Analysis of genetic variation in Macadamia shows evidence of extensive reticulate evolution

The genus Macadamia in the Proteaceae family includes four species. To explore diversity in macadamia genetic resources, a total of 166 wild genotypes, representing all four species, were sequenced. The four species were clearly distinguished as four separate clades in a phylogenetic analysis of nuclear gene CDS. M. integrifolia and M. tetraphylla formed a clade that had diverged from a clade including M. ternifolia and M. jansenii. The greatest diversity in nuclear and chloroplast genomes was found in the more widely distributed M. integrifolia while the rare M. jansenii showed little diversity. The chloroplast phylogeny revealed a much more complex evolutionary history. Multiple chloroplast capture events have resulted in chloroplast genome clades including genotypes from different species. This suggests extensive reticulate evolution in Macadamia despite the emergence of the four distinct species that are supported by the analysis of their nuclear genomes. The chloroplast genomes showed strong associations with geographical distribution reflecting limited maternal gene movement in these species having large seeds. The nuclear genomes showed lesser geographical differences, probably reflecting longer distance movement of pollen. This improved understanding of the distribution of diversity in Macadamia will aid conservation of these rare species now found in highly fragmented rainforest remnants. HighlightsWhole genome sequencing of population of the four species in the Macadamia genus allowed phylogenetic relationships to be determined and revealed significant reticulate evolution.

evolutionary biology↗

bioRxiv2024

A flow cytometry protocol for accurate and precise measurement of plant genome size using frozen material

Flow cytometry is a technique widely applied to infer the ploidy and genome size of plant nuclei. The conventional approach of sample preparation, reliant on fresh plant material to release intact nuclei, requires protocol optimisation for application to many species. The approach often results in poor yields of nuclei, impeding the accurate measurement of genome size and confines the optimal resource allocation and efficiency in genome sequencing which relies on genome size estimation. Here, we present a novel method using frozen plant material that facilitates the release of intact nuclei for genome size estimation. Genome estimates from frozen material are similar to those from fresh material. Accurate and precise estimates can be made by complementing the fluorescence of frozen nuclei with histogram modelling and debris compensation algorithms. This method of nuclei isolation from frozen plant material for flow cytometry-based genome size estimations has special value in estimating the genome size of samples collected and frozen for use in plant genome sequencing. Plant material can be conveniently stored, resampled, and used for DNA or RNA extractions. HighlightFrozen leaf material can be used to isolate nuclei for the accurate estimation of genome size The method proved suitable for difficult samples and did not require specific optimization. The method was especially useful where plant material could not be immediately processed through flow cytometry and allowed the same sample to be used for genomes size estimation and genome sequencing.

genomics↗

bioRxiv2023

An improved haplotype resolved genome reveals more rice genes

The rice reference genome (Oryza sativa ssp. japonica cv. Nipponbare) has been an important resource in plant science. We now report an improved and haplotype resolved genome sequence based upon more accurate sequencing technology. This improved assembly includes regions missing in earlier genomes sequences and the annotation of more than 3,000 new genes due to greater sequence accuracy.

genomics↗

bioRxiv2023

The genomes of the Macadamia genus

Macadamia, a genus native to Eastern Australia, comprises four species, Macadamia integrifolia, M. tetraphylla, M. ternifolia, and M. jansenii. Macadamia was recently domesticated largely from a limited gene pool of Hawaiian germplasm and has become a commercially significant nut crop. Disease susceptibility and climate adaptability challenges, highlight the need for use of a wider range of genetic resources for macadamia production. High quality haploid resolved genome assemblies were generated using HiFiasm to allow comparison of the genomes of the four species. Assembly sizes ranged from 735 Mb to 795 Mb and N50 from 53.7 Mb to 56 Mb, indicating high assembly continuity with most of the chromosomes covered telomere to telomere. Repeat analysis revealed that approximately 61% of the genomes were repetitive sequence. The BUSCO completeness scores ranged from 95.0% to 98.9%, confirming good coverage of the genomes. Gene prediction identified 37198 to 40534 genes. The ks distribution plot of Macadamia and Telopea suggests Macadamia has undergone a whole genome duplication event prior to divergence of the four species and that Telopea genome was duplicated more recently. Synteny analysis revealed a high conservation and similarity of the genome structure in all four species. Differences in the content of genes of fatty acid and cyanogenic glycoside biosynthesis were found between the species. An antimicrobial gene with a conserved cysteine motif was found in all four species. The four genomes provide reference genomes for exploring genetic variation across the genus in wild and domesticated germplasm to support plant breeding.

genomics↗

bioRxiv2023

Determination of phylogenetic relationships in the genus Mangifera based on whole chloroplast genome and nuclear genome sequences

The genus Mangifera (Anacardiaceae) includes 69 species of which Mangifera indica L. is the most important and primarily cultivated species for commercial mango production. Although the species are classified based on morphological descriptors, molecular evidence has proposed the hybrid origin of two species suggesting the possibility that more of the species may be of hybrid origin. To analyze evolutionary relationships within the genus, 13 samples representing 11 Mangifera species were sequenced and whole chloroplast (Cp) genomes and 47 common single-copy nuclear gene sequences were assembled and used for phylogenetic analysis using concatenation and coalescence-based methods. The Cp genome size varied from 151,752 to 158,965 bp with M. caesia and M. laurina having the smallest and largest genomes, respectively. Genome annotation revealed 80 protein-coding genes, 31 tRNA and four rRNA genes across all the species. Comparative analysis of whole Cp genome sequence and nuclear gene-based phylogenies revealed topological conflicts suggesting chloroplast capture or cross hybridization. The Cp genomes of M. altissima, M. applanata, M. caloneura and M. lalijiwa were similar to those of M. indica (99.9% sequence similarity). Their close sequence relationship suggests a common ancestry and likely cross-hybridization between wild relatives and M. indica. This study provides improved knowledge of phylogenetic relationships in Mangifera, indicating extensive gene flow among the different species, suggesting that hybrids may be common within the genus.

plant biology↗

bioRxiv2022

Haplotype resolved chromosome level genome assembly of Citrus australis reveals disease resistance and other citrus specific genes

Recent advances in genome sequencing and assembly techniques have made it possible to achieve chromosome level reference genomes for citrus. Relatively few genomes have been anchored at the chromosome level and/or are haplotype phased, with the available genomes of varying accuracy and completeness. We now report a phased high-quality chromosome level genome assembly for an Australian native citrus species; Citrus australis (round lime) using highly accurate PacBio HiFi long reads, complemented with Hi-C scaffolding. Hifiasm with Hi-C integrated assembly resulted in a 331 Mb genome of C. australis with two haplotypes of nine pseudochromosomes with an N50 of 36.3 Mb and 98.8% genome assembly completeness (BUSCO). Repeat analysis showed that more than 50% of the genome contained interspersed repeats. Among them, LTR elements were the predominant type (21.0%), of which LTR Gypsy (9.8 %) and LTR copia (7.7 %) elements were the most abundant repeats. A total of 29,464 genes and 32,009 transcripts were identified in the genome. Of these, 28,222 CDS (25,753 genes) had BLAST hits and 21,401 CDS (75.8%) were annotated with at least one GO term. Citrus specific genes for antimicrobial peptides, defense, volatile compounds and acidity regulation were identified. This chromosome scale, and haplotype resolved C. australis genome will facilitate the study of important genes for citrus breeding and will also allow the enhanced definition of the evolutionary relationships between wild and domesticated citrus species.

plant biology↗

bioRxiv2021

De-novo chromosome level assembly of plant genomes from long read sequence data

Recent advances in the sequencing and assembly of plant genomes have allowed the generation of genomes with increasing contiguity and sequence accuracy. The chromosome level assembly of the contigs generated from long read sequencing has involved the use of proximity analysis (Hi-C) or traditional genetic maps to guide the placement of sequence contigs within chromosomes. The development of highly accurate long reads by repeated sequencing of circularized DNA (PacBio HiFi) has greatly increased the size of contigs. We now report the use of HiFiasm to assemble the genome of Macadamia jansenii. a genome that has been used as model to test sequencing and assembly. This achieved almost complete chromosome level assembly from the sequence data alone without the need for higher level chromosome map information. Eight of the 14 chromosomes were represented by a single large contig and the other 6 assembled into 2-4 main contigs. The small number of chromosome breaks appear to be due to highly repetitive regions of ribosomal genes that cannot be assembled by these approaches. De novo assembly of near complete chromosome level plant genomes now seems possible using these sequencing and assembly tools. Further targeted strategies might allow these remaining gaps to be closed. Significance statement (of up to two sentences)De novo assembly of near complete chromosome level plant genomes is now possible using current long read sequencing and assembly tools.

genomics↗

bioRxiv2021

The genome of the endangered Macadamia jansenii displays little diversity but represents an 1 important genetic resource for plant breeding

Macadamia, a recently domesticated expanding nut crop in the tropical and subtropical regions of the world, is one of the most economically important genera in the diverse and widely adapted Proteaceae family. All four species of Macadamia are rare in the wild with the most recently discovered, M. jansenii, being endangered. The M. jansenii genome has been used as a model for testing sequencing methods using a wide range of long read sequencing techniques. Here we report a chromosome level genome assembly, generated using a combination of Pacific Biosciences sequencing and Hi-C, comprising 14 pseudo-molecules, with a N50 of 58 Mb and a total 758 Mb genome assembly size of which 56% is repetitive. Completeness assessment revealed that the assembly covered 96.9% of the conserved single copy genes. Annotation predicted 31,591 protein coding genes and allowed the characterization of genes encoding biosynthesis of cyanogenic glycosides, fatty acid metabolism and anti-microbial proteins. Re-sequencing of seven other genotypes confirmed low diversity and low heterozygosity within this endangered species. Important morphological characteristics of this species such as small tree size and high kernel recovery suggest that M. jansenii is an important source of these commercial traits for breeding. As a member of a small group of families that are sister to the core eudicots, this high-quality genome also provides a key resource for evolutionary and comparative genomics studies.

genomics↗

bioRxiv2021

Allele expression biases in mixed-ploid sugarcane accessions

Allele-specific expression (ASE) represents differences in the magnitude of expression between alleles of the same gene. This is not straightforward for polyploids, especially autopolyploids, as knowledge about the dose of each allele is required for accurate estimation of ASE. This is the case for the genomically complex Saccharum species, characterized by high levels of ploidy and aneuploidy. We used a Beta-Binomial model to test for allelic imbalance in Saccharum, with adaptations for mixed-ploid organisms. The hierarchical Beta-Binomial model was used to test if allele expression followed the expectation based on genomic allele dosage. The highest frequencies of ASE occurred in sugarcane hybrids, suggesting a possible influence of interspecific hybridization in these genotypes. For all accessions, ASEGs were less frequent than those with balanced allelic expression. These genes were related to a broad range of processes, mostly associated with general metabolism, organelles, responses to stress and responses to stimuli. In addition, the frequency of ASEGs in high-level functional terms was similar among the genotypes, with a few genes associated with more specific biological processes. We hypothesize that ASE in Saccharum is largely a genotype-specific phenomenon, as a large number of ASEGs were exclusive to individual accessions.

genomics↗

bioRxiv2021

Improvements in the Sequencing and Assembly of Plant Genomes

BackgroundAdvances in DNA sequencing have reduced the difficulty of sequencing and assembling plant genomes. A range of methods for long read sequencing and assembly have been recently compared and we now extend the earlier study and report a comparison with more recent methods. ResultsUpdated Oxford Nanopore Technology software supported improved assemblies. The use of more accurate sequences produced by repeated sequencing of the same molecule (PacBio HiFi) resulted in much less fragmented assembly of sequencing reads. The use of more data to give increased genome coverage resulted in longer contigs (higher N50) but reduced the total length of the assemblies and improved genome completeness (BUSCO). The original model species, Macadamia jansenii, a basal eudicot, was also compared with the 3 other Macadamia species and with avocado (Persea americana), a magnoliid, and jojoba (Simmondsia chinensis) a core eudicot. In these phylogenetically diverse angiosperms, increasing sequence data volumes also caused a highly linear increase in contig size, decreased assembly length and further improved already high completeness. Differences in genome size and sequence complexity apparently influenced the success of assembly from these different species. ConclusionsAdvances in long read sequencing technology have continued to significantly improve the results of sequencing and assembly of plant genomes. However, results were consistently improved by greater genome coverage (using an increased number of reads) with the amount needed to achieve a particular level of assembly being species dependant.

genomics↗

bioRxiv2020

Chromosome-scale assembly and annotation of the macadamia genome(Macadamia integrifolia HAES 741)

Macadamia integrifolia is a representative of the large basal eudicot family Proteaceae and the main progenitor species of the Australian native nut crop macadamia. Since its commercialisation in Hawaii fewer than 100 years ago, global production has expanded rapidly. However, genomic resources are limited in comparison to other horticultural crops. The first draft assembly of M. integrifolia had good coverage of the functional gene space but its high fragmentation has restricted its use in comparative genomics and association studies. Here we have generated an improved assembly of cultivar HAES 741 (4,094 scaffolds, 745 Mb, N50 413 kb) using a combination of Illumina paired and PacBio long read sequences. Scaffolds were anchored to 14 pseudo-chromosomes using seven genetic linkage maps. This assembly has improved contiguity and coverage, with >120 Gb of additional sequence. Following annotation, 34,274 protein-coding genes were predicted, representing 92% of the expected gene content. Our results indicate that the macadamia genome is repetitive and heterozygous. The total repeat content was 55% and genome-wide heterozygosity, estimated by read mapping, was 0.98% or one SNP per 102 bp. This is the first chromosome-scale genome assembly for macadamia and the Proteaceae. It is expected to be a valuable resource for breeding, gene discovery, conservation and evolutionary genomics.

genomics↗

bioRxiv2020

Comparison of long read methods for sequencing and assembly of a plant genome

Sequencing technologies have advanced to the point where it is possible to generate high accuracy, haplotype resolved, chromosome scale assemblies. Several long read sequencing technologies are available on the market and a growing number of algorithms have been developed over the last years to assemble the reads generated by those technologies. When starting a new genome project, it is therefore challenging to select the most cost-effective sequencing technology as well as the most appropriate software for assembly and polishing. For this reason, it is important to benchmark different approaches applied to the same sample. Here, we report a comparison of three long read sequencing technologies applied to the de novo assembly of a plant genome, Macadamia jansenii. We have generated sequencing data using Pacific Biosciences (Sequel I), Oxford Nanopore Technologies (PromethION) and BGI (single-tube Long Fragment Read) technologies for the same sample. Several assemblers were benchmarked in the assembly of PacBio and Nanopore reads. Results obtained from combining long read technologies or short read and long read technologies are also presented. The assemblies were compared for contiguity, accuracy and completeness as well as sequencing costs and DNA material requirements. Overall, the three long read technologies produced highly contiguous and complete genome assemblies of Macadamia jansenii. At the time of sequencing, the cost associated with each method was significantly different but continuous improvements in technologies have resulted in greater accuracy, increased throughput and reduced costs. We propose updating this comparison regularly with reports on significant iterations of the sequencing technologies.

genomics↗

bioRxiv2019

Structural elements that modulate the substrate specificity of plant purple acid phosphatases: avenues for improved phosphorus acquisition in crops

Phosphate acquisition by plants is an essential process that is directly implicated in the optimization of crop yields. Purple acid phosphatases (PAPs) are ubiquitous metalloenzymes, which catalyze the hydrolysis of a wide range of phosphate esters and anhydrides. While some plant PAPs display a preference for ATP as the substrate, others are efficient in hydrolyzing phytate or 2-phosphoenolpyruvate (PEP). PAP from red kidney bean (rkbPAP) is an efficient ATP- and ADPase, but has no activity towards phytate. The crystal structure of this enzyme in complex with an ATP analogue (to 2.20 [A] resolution) provides insight into the amino acid residues that play an essential role in binding this substrate. Homology modelling was used to generate three-dimensional structures for the active sites of PAPs from tobacco (NtPAP) and Arabidopsis thaliana (AtPAP12 and AtPAP26) that are efficient in hydrolyzing phytate and PEP as substrates, respectively. In combination with substrate docking simulations and a phylogenetic analysis of 49 plant PAP sequences (including the first PAP sequences reported from Eucalyptus), several active site residues were identified that are important in defining the substrate specificities of plant PAPs. These results may inform bioengineering studies aimed at identifying and incorporating suitable plant PAP genes into crops to improve phosphorus use efficiency. Organic phosphorus sources increasingly supplement or replace inorganic fertilizer, and efficient phosphorus use of crops will lower the environmental footprint of agriculture while enhancing food production.

biochemistry↗